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AC 91-70C - Oceanic and Remote Continental Airspace Operations
Reproduced for study. Always verify against the official GACAR at gaca.gov.sa.
U.S. Department
of Transportation
Federal Aviation
Administration Advisory
Circular
Subject: Oceanic and Remote Continental
Airspace Operations Date: 10/4/23 AC No: 91-70C
Initiated by: AFS-400 Change:
This advisory circular (AC) contains both general information and detailed guidance for
operators planning flights in oceanic and remote continental airspace. This includes Performance -based Navigation (PBN) and Special Areas of Operation (SAO). The Federal
Aviation Administration (FAA) revised this AC to focus on the evolving operations in oceanic and remote continental airspace. This AC is laid out in a building block format, beginning with foundational information, followed by information on the training, authorizations, and equipment required to operate most efficiently in this airspace, and finishing with flight planning, flight execution, and contingency operations guidance. Our goal is to provide you with a template to guide you through planning and executing flight operations through oceanic and remote continental airspace. Information related to international operations in specific locales continues to be available in the North Atlantic (NAT) Resource Guide for United States Operators ; the
West Atlantic , Gulf of Mexico, and Caribbean Resource Guide for U.S. Operators ; a nd the
Pacific Resource Guide for U.S. Operators. These online resource guides, along with Notices to
Air Missions (NOTAM) and FAA International Notices, provide the most current information
available to pilots, aircraft dispatchers , and other operational control personnel preparing for
oceanic and international operations. We have also included hyperlinks to many documents, available free or for purchase. While we carefully checked at the time of publi cation that
information included in this AC is current, oceanic and remote continental airspace operations are constantly evolving, and it is incumbent on you, the operators, to ensure you are flying with current information.
This AC neit he
r is mandatory nor does it constitute a regulation. When this AC uses mandatory
language (e.g., “must” or “may not”), it is quoting or paraphrasing a regulatory requirement or prohibition. When this AC uses permissive language (e.g., “should” or “may”), it describes an
acceptable means, but not the only means, of conducting that aspect of operations in oceanic and remote continental airspace. However, if you use the means described in the AC, you must follow them in all important respects.
Wesl
ey L. Mooty
Acting Deputy Executive Director, Flight Standards Service
10/4/23 AC 91 -70C
ii CONTENTS
Paragraph Page
Chapter 1. General ....................................................................................................................... 1-1
1.1 Purpose of This Advisory Circular (AC ) ...................................................................... 1-1
1.2 Audience ....................................................................................................................... 1-1
1.3 Where You Can Find This AC ...................................................................................... 1-1
1.4 What This AC Cancels.................................................................................................. 1-1
1.5 Fundamental Changes From Previous Edition ............................................................. 1-1
1.6 Related Title 14 Of The Code Of Federal Regulations (14 CFR ) Parts ....................... 1-1
1.7 Related Read ing Material (Current Editions) ............................................................... 1-2
1.8 AC Feedback Form ....................................................................................................... 1-3
Chapter 2. Background Information for Operations in Oceanic and R emote
Continental Airspace .................................................................................................. 2-1
2.1 ICAO: Its Relationship t o U.S. Aviation ...................................................................... 2-1
2.2 ICAO Annexes .............................................................................................................. 2-1
2.3 Applicability of U.S. and International Regulations ..................................................... 2-3
2.4 ICAO Guidance Documents a nd Reference Material ................................................... 2-5
2.5 Authorization to Operate in Oceanic/Remote Continental Airspace and Special
Areas of Oper ation (SAO) ............................................................................................ 2-9
2.6 Authorization Process ................................................................................................... 2-9
2.7 Web -Based Operations Safety System (WebOPSS )................................................... 2-10
Chapter 3. Pilot Qualification and Training Guidance for Oceanic and Remote Continental
Airspace Operations ................................................................................................... 3-1
3.1 Training Requirements for Oceanic a nd Remote Continental Airspace
Operations ..................................................................................................................... 3-1
Chapter 4. Communications, Navigation, and S urvei llance Systems Guidance for
Operations in Oceanic a nd Remote Continent al Airspace ......................................... 4-1
4.1 Communications, Navigation, and Surveillance Improvements—Impact
on ATS .......................................................................................................................... 4-1
4.2 Performance -Based Operations .................................................................................... 4-1
4.3 Voice Communications i n Oceanic Airspace ............................................................... 4-3
4.4 CPDLC a nd Automatic Dependent Surveillance -Contract (ADS -C) ........................... 4-7
4.5 Data Link Sys tems —Operational Authorization t o Use ............................................... 4-9
10/4/23 AC 91 -70C
iii 4.6 ATC in Oceanic and Remote Contine ntal Airspace ................................................... 4-10
4.7 Special Use Airspace ( SUA) ....................................................................................... 4-12
4.8 Air Defense Identification Zones ( ADIZ ) ................................................................... 4-13
4.9 World Geodetic System 1984 ( WGS 84).................................................................... 4-13
Chapter 5. Flight Planning Guidance for International and Oceanic and Remote
C
ontinental Airspace Operations ............................................................................... 5-1
5.1 Lead Time Requirements .............................................................................................. 5-1
5.2 Preparing an Itinerary ................................................................................................... 5-1
5.3 Crew Fatigue ................................................................................................................. 5-4
5.4 Required Paperwork/Documentation ............................................................................ 5-4
5.5 Entry to Foreign Airspace—Flight Plan vs. Formal Advance Permission ................... 5-7
5.6 Managing Risk in Oceanic and Remote Continental Airspace Operations .................. 5-7
5.7 Weather Forecasts and Other Meteorological Planning ............................................... 5-7
5.8 FAA International Notices Website .............................................................................. 5-8
5.9 ETOPS .......................................................................................................................... 5-8
5.10 Polar Operations .......................................................................................................... 5-9
5.11 Areas With Limited o r No ATS (Also Called “No FIR ” Areas) ................................. 5-9
5.12 Rotorcraft Operations ................................................................................................ 5-10
Chapter 6. Flight Execution Guidance for Operations in Oceanic and Remote
C
ontinental Airspace .................................................................................................. 6-1
6.1 General Information ...................................................................................................... 6-1
6.2 Flight Plan ..................................................................................................................... 6-5
6.3 Aircraft Preflight Guidance ........................................................................................... 6-6
6.4 En Route Guidance ..................................................................................................... 6-12
Chapter 7. In -F light Contingency Guidance for Operations i n Oceanic Airspace ...................... 7-1
7.1 Contingency Procedures: When They May Be Needed ............................................... 7-1
7.2 Choosing The Correct Contingency Procedure ............................................................ 7-1
7.3 Altimetry a nd/or Navigation Degradation .................................................................... 7-2
7.4 Lost Communications Procedures ................................................................................ 7-2
7.5 Normal Aircraft Tracking ............................................................................................. 7-3
10/4/23 AC 91 -70C
iv Appendix A. Abbreviations a nd Definitions ............................................................................ A-1
Appendix B. Sp ecial Areas of Operation and OpSpecs/MSpecs/L OAs ...................................B-1
Appendix C. Unusual Weather Activity ....................................................................................C-1
A
ppendix D. Sam ple Oceanic Checklist .................................................................................. D-1
Appendix E. IAT A In-Flight Broadcast Procedure ................................................................... E-1
Appendix F. Sp ecial Procedures for In -Flight Contingencies i n Oceanic Airspace ................. F-1
Appendix G. Sugge sted Subjects for Inclusion in Oceanic and International Procedures
and/or an Operations Manual .............................................................................. G-1
List of Figures
Fi
gure 4-1. Sample CPDLC Route Uplinks .............................................................................. 4-9
Figure 6-1. Sa mple Plotting Chart ............................................................................................. 6-8
Figure C-1. IC AO Volcanic Ash Advisory Centers .................................................................. C-1
Figure C-2. Ex ample of a National Oceanic and Atmospheric Administration Scales
Activity Report....................................................................................................... C-3
Figure E-1. Ma p of IFBP Area of Applicability ........................................................................ E-2
Figure F-1. Sp ecial Procedures for In -Flight Contingencies in Oceanic Airspace
(Non -Weather) ........................................................................................................ F-1
Figure F-2. Sp ecial Procedures for In -Flight Weather Contingencies ....................................... F-6
List of Tables
Tab
le 6-1. Examples of Incorrectly Applied Conditional Clearances ...................................... 6-2
Table B -1. SAO -Related OpSpecs/MSpecs/LOAs .................................................................. B-1
Table B -2. Ocean ic and Remote/General En Route OpSpecs/MSpecs/LOAs ........................ B-2
Table F -1. Al titude Offset When Denied Clearance to Deviate 9.3 km (5.0 NM) or More
(5 NM Procedures) .................................................................................................. F-7
10/4/23 AC 91 -70C
1-1 CHAPTER 1. GENERAL
1.1 Purpose of This Advisory Circular (AC). The Federal Aviation Administration (FAA)
(“we”) developed this AC to provide general information and guidance for certificated
and General Aviation (GA) operators (“you”) planning flights in oceanic and remote continental airspace. This guidance includes the authorizations you may need for
operations in such airspace. The contents of this document do not have the force and
effect of law and are not meant to bind the public in any way, and the document is intended only to provide information to the public regarding existing requirements under the law or agency policies.
1.2 Audience. We wrote this AC primarily for operators who do not have experience with
flying in oceanic and remote continental airspace, to assist in developing their own procedures. We also wr ote this AC for GA pilots who do not fly regularly in oceanic and
remote continental airspace and need a refresher in planning and executing such a flight. Most certificated operators have company procedures for operations in oceanic and remote continental airspace. Those procedures have been accepted by FAA inspectors
and conform to all relevant regulations and guidance. If you are working for one of these operators, this AC may serve to reinforce your company procedures.
1.3 Where You Can Find This AC. You can find this AC on the FAA’s website at
https://www.faa.gov/regulations_policies/advisory_circulars
1.4 What This AC Cancels. AC 91 -70B CHG 1 , Oceanic and Remote Continental
Operations, dated February 1, 2019, is canceled.
1.5 Fundamental Changes From Previous Edition. This revi sion of AC 91-70 contains
numerous changes from the previous edition, many of which clarify or amplify information provided earlier. Operators should review this revised AC in its entirety. We
have added information on the use of Satellite Voice (SATVOICE) communications,
Controller- Pilot Data Link Communication (CPDLC), and space-based Automatic
Dependent Surveillance -Broadcas t (ADS -B), as well as updated information on common
causes of pilot deviations and re- emphasized the importance of accurate flight plan
equipment and capability codes. We updated the contingency procedures, in line with International Civil Aviation Organiz ation ( ICAO) changes, and explain the requirements
for oceanic authorizations. Finally, we provide updated links to the most current sources of international material.
1.6 Related Title 14 of the Code of Federal Regulations (14 CFR) Parts.
• Part 91, §§ 91.1 through 91.21, 91.101 through 91.143, 91.151 through 91.159
,
91.167 through 91.193, 91.203, 91.205, 91.209 through 91.217, 91.221, 91.225 ,
91.227, 91.303 through 91.319, 91.323, 91.509, 91.511, 91.605, 91.609, 91.703
through 91.715, 91.903, 91.1039, and 91.1073; and Appendix G .
• Part 119, §§ 119.5, 119.49, 119.59, and 119.63 .
10/4/23 AC 91 -70C
1-2 • Part 121, §§ 121.11, 121.101, 121.121, 121.163, 121.339, 121.351, 121.353, 121.355,
121.401, 121.415, 121.427, and 121.445; and Appendix G .
• Part 125, §§ 125.23, 125.45, 125.51, 125.203, 125.209, 125.296, and 125.363.
• Part 135, §§ 135.3, 135.43, 135.145, 135.165, 135.167, 135.183, 135.213, 135.323,
135.329, 135.351, 135.364, and 135.381; and Appendix G .
1.7 Related Reading Material (current editions).
1.7.1 RT CA Documents . Available for purchase on the RTCA website at
https://www.rtca.org/standards .
1. RTCA/DO-258/ED-100, Interoperability Requirements for ATS Applications Using
ARINC 622 Data Communications.
2. RTCA/DO-260/ED- 102, Minimum Operational Performance Standards (MOPS) for
1090 MHz Extended Squitter Automatic Dependent Surveillance- Broadcast (ADS -B)
and Traffic Information Services – Broadcast (TIS -B).
3. RTCA/DO -306/ED- 122, Safety and Performance Standard for Air Traffic Data Link
Services in Oceanic and Remote Airspace (Oceanic SPR Standard).
4. RTCA/ DO-350/ED-228, Safety and Performance Requirements Standard for
Baseline 2 ATS Data Communications (Baseline 2 SP R Standard).
1.7.2 F AA Technical Standard Orders (TSO) .
1. TSO -C115, Flight Management System (FMS) Using Multi-Sensor Inputs.
2. TSO -C145, Airborne Navigation Sensors Using The Global Positioning System
Augmented by the Satellite Based Augmentation System (SBAS).
3. TSO - C146, Stand-Alone Airborne Navigation Equipment Using The Global
Positioning System Augmented by the Satellite Based Augmentation System (SBAS).
4. TSO - C196, Airborne Supplemental Navigation Sensors for Global Positioning
System Equipment Using Aircraft -Based Augmentation.
1.7.3 FAA ACs .
1. AC 20-138, Airworthiness Approval of Positioning and Navigation Systems.
2. AC 20-140, Guidelines for Design Approval of Aircraft Data Link Communication
Systems Supporting Air Traffic Services (ATS).
3. AC 20-150, Airworthiness Approval of Satellite Voice (SATVOICE) Equipment
Supporting Air Traffic Service (ATS) Communication.
4. AC 90-80, Approval of Offshore Standard Approach Procedures, Airborne Radar
Approaches, and Helicopter En Route Descent Areas.
10/4/23 AC 91 -70C
1-3 5. AC 90-96
, Approval of U.S. Operators and Aircraft to Operate Under Instrument
Flight Rules (IFR) in European Airspace Designated for Basic Area Navigation
(B-RNAV) and Precision Area Navigation (P -RNAV).
6. AC 90- 105, Approval Guidance for RNP Operations and Barometric Vertical
Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace.
7. AC 90-
114, Automatic Dependent Surveillance -Br oadcast Operations.
8. AC 90-117, Data Link Communications.
9. AC 91-85, Authorization of Aircraft and Operators for Flight in Reduced Vertical
Separation Minimum (RVSM) Airspace.
10. AC 91- 92, Pilot’s Guide to a Preflight Briefing .
11. AC 120-42, Extended Operations (ETOPS and Polar Operations).
12. AC 120-100, Basics of Aviation Fatigue.
13. AC 120-103, Fatigue Risk Management Systems for Aviation Safety.
14. AC 121-31, Flight Crew Sleeping Quarters and Rest Facilities.
15. AC 135-42, Extended Operations (ETOPS) and Operations in the North Polar Area.
1.7.4 FAA IFR Enroute Aeron autical Planning Charts . These charts are available at
https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/ifr.
1. North Atlantic Route Chart.
2. North Pacific Route Chart.
3. Western Atlantic Route System Chart.
1.8 AC Feedback Form. For your convenience, the AC Feedback Form is the last page of
this AC. Note any deficiencies found, clarifications needed, or suggested improvements regarding the contents of this AC on the AC Feedback Form.
10/4/23 AC 91 -70C
2-1 CHAPTER 2. BACKGROUND INFORMATION FOR OPERATIONS IN OCEANIC
AND REMOTE CONTINENTAL AIRSPACE
2.1 ICAO and Its Relationship to U.S. Aviation. The United States is a Contracting State
to the Convention on International Aviation (Chicago Convention) and an ICAO Member
State and has fully supported the organization’s goa ls from its inception. ICAO works to
achieve the highest level of standards and procedures for aircraft, personnel, airways, and aviation services throughout the world. ICAO oversees the international standards ascribed to by its more than 190 Member State s for navigation facilities, airports,
weather, and radio services. Through active support and participation in ICAO, the FAA strives to improve worldwide safety standards and procedures. ICAO’s strategic objectives are to continue to establish and maintain Standards and Recommended Practices (SARP s) for the safe and orderly development of international aviation. The
19 Annexes to the Chicago Convention (ICAO Annexes) contain more than 10,000 adopted SARPs.
Note: ICAO Member States are obligated to “collaborate i n securing the highest
practicable degree of uniformity in regulations” and generally achieve this by
complying with the SARPs contained in the 19 Annexes and supporting ICAO documents such as ICAO Doc 4444 , Procedures for Air Navigation Services —
Air
Traffic Management, and ICAO Doc 7030, Regional Supplementary Procedures.
States notify ICAO of their “differences” with SARPs and publish them in their Aeronautical Information Publication (AIP ).
2.2 IC
AO Annexes. Find all ICAO Annexes at the ICAO store at https://store.icao.int.
2.2.1 Annex 1, Personnel Licensing. Provides information on licensing of flightcrews, air
traffic controllers, and aircraft maintenance personnel, including medical standards for flightcrews and air traffic controllers.
2.2.2 Annex 2, Rules of the Air .
Contains visual flight r ules (VFR) and instrument flight rules
(IFR) for all operators.
2.2.3 Annex 3, Meteorological Service for International Air Navigation. Provides for
meteorological services for international air navigation and reporting of meteorological observations from aircra ft.
2.2.4 Annex 4, Aeronautical Charts .
Contains specifications for aeronautical charts used in
international aviation.
2.2.5 Annex 5, U nits of Measurement to be Used in Air and Ground Operation s. Lists
dimensional systems used in air and ground operations.
2.2.6 Annex 6, O p eration of Aircraft (3 Parts). Specifies minimum standards for below -listed
operations throughout the world:
10/4/23 AC 91 -70C
2-2 1. Part I, International Commercial Air Transport— Aeroplanes.
2. Part II, International General Aviation —Aeroplanes.
3. Part III, International Operations —Helicopters.
2.2.7 Annex 7, Aircraft Nationality and Registration Marks . Specifies requirements for
registration and identification of aircraft.
2.2.8 A nnex 8, Airworthiness of Aircraft. Specifies uniform procedures for certification and
inspection of aircraft.
2.2.9 A nnex 9, Facilitation. Provides for the standardization and simplification of
border- crossing formalities.
2.2.10 A nnex 10, Aeronautical Telecommunications:
1. Volume I, Radio Navigation Aids. Provides for standardizing communications
equipment and systems.
2. Volume II, Communication Procedures including those w ith PANS status.
Standardizes communications procedures.
3. Volume III, Communication Systems. Standardizes communications systems.
4. Volume IV, Surveillance and Collision Avoidance Systems. Standardizes surveillance radar and collision avoidance.
5. Volume V, Aeronautical Radio Frequency Spectrum Utilization. Standardizes aeronautical radio spectrum utilization.
2.2.11 Annex 11, Air Traffic Services. Includes information on establishing and operating a ir
traffic control (ATC), flight information, and alerting services.
2.2.12 A nnex 12, Search and Rescue. Provides information on organization and operation of
facilities and services necessary for Search and Rescue (SAR).
2.2.13 A nnex 13, Aircraft Accident and Incident Investigation. Provides for uniformity in
notifying, investigating, and reporting on aircraft accidents.
2.2.14 A nnex 14, Aerodromes:
1. Volume I, Aerodrome Design and Operations. Contains specifications for the design and equipment of aerodromes.
2. Volume II, Helipor ts. Contains specifications for the design and equipment of
heliports.
2.2.15 Annex 15, Aeronautical Information Services . Includes methods for collecting and
disseminating aeronautical information required for flight operations.
10/4/23 AC 91 -70C
2-3 2.2.16 A nnex 16, Environmental Protection:
1. Volume I, Aircraft Noise. Contains specifications for aircraft noise certification, noise
monitoring, and noise exposure units for land- use planning.
2. Volume II, Aircraft Engine Emissions. Contains specifications for aircraft engine emissions.
3. Volume III, Aeroplane CO
2 Emissions.
4. Volume IV, Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).
2.2.17 A
nnex 17, Security. Specifies methods for safeguarding international civil aviation
against unlawful acts of interference.
2.2.18 Annex 18, The Safe Transport of Dangerous Goods by Air . Contains specifications for
labeling, packing, and shipping dangerous cargo.
2.2.19 Annex 19, Safety Management . Describes Safety Management System (SMS)
development, regulatory framework, and supporting guidance.
2.3 A pplicabilit y of U.S. and International Regulations.
2.3.1 FAA regulations relating to certification, airworthiness, licensing, and certain operational aspects (e.g., operational control, communication and navigation equipment, and Extended Operations ( ETOPS) ), are applicab le to U. S. operators wherever they fly. Some
of these regulations are fundamental to oceanic operations:
2.3.1.1 Title 14 CFR part 91, § 91.511 (applicable to part 91 subpart F), deals with
“overwater” operations which are more than 30 minutes or 100 nautical miles (NM) from the nearest shore .
Note: S
ection 91.511(b) notes that a unit is “independent if the
function of any part of it does not depend on the functioning of any part of another receiver or electronic navigation unit. ”
2.3.1.1.1 For such operations, two independent long- range navigation systems (LRN S)
are required, except in an area defined by coordinates in § 91.511(f), where only one LRNS is sufficient.
2.3.1.1.2 Part 91 subpart F overwater operations outside very high frequency ( VHF )
voice communication coverage require two long-range communication systems (LRCS ), except when an aircraft has two VHF radios, in which case
only one high frequency ( HF) radio is sufficient.
2.3.1.2 Title 14 CFR part 121, § 121.351; part 125, § 125.203; and part 135,
§ 135.165 use a different term, “extended over-water” operations, defined in
14 CFR part 1, § 1.1 as more than 5 0 NM from the nearest shoreline.
10/4/23 AC 91 -70C
2-4 2.3.1.2.1 Section 121.351 specifically requires two “independent long-range navigation
systems” for extended over -water operations.
2.3.1.2.2 Sections 125.203 and 135.165 use different language, and only require “two approved independent navigation systems suitable for navigating the airplane along the route” within the “degree of accuracy required for ATC.” This
allows extended over -water operations along ATS routes that have
ground-based Navigational Aid (NAVAID) coverage, without any LRNS.
2.3.1.2.3 For parts 121, 125, and 135, extended over- water operations “in certain
geographic areas” with only a single LRNS can be authorized via operations specification ( OpSpec ) B054, which defines an area by coordinates where
only one LRNS is sufficient.
2.3.1.2.4 Extended ove rwater operations outside VHF voice communication coverage
require two LRCS s, except for holders of OpSpec B045, which defines an
area by coordinates where only one LRCS is sufficient.
2.3.2 FAA regulations governing “F light Rules” ( this is the title of part 91 subpart B
), on the
other hand, are applicable to all operators, in U.S. sovereign airspace only.1 These
so-called “flight and maneuver” regulations are generally harmonized with ICAO rules,
in accordance with Article 12 to the Chicago Convention. Exceptions are listed as
“Differences” in the relevant AIP. In the U.S. AIP, these are found in Section GEN 1.7,
Differences From ICAO Standards, Recommended Practices and Procedures.
2.3.3 U.S. operators flying outside U.S. sovereign airspace must abide by the “flight and maneuver” regulations in effect for that airspace. If the airspace is “high seas” (“high seas” airspace generally begins outside 12 NM from the nearest shore), the applicab le
rules are found in ICAO Annex 2 (titled “Rules of the Air”), and ICAO Doc 7030.
2 In
other countries’ sovereign airspace, information on regulations is found in the relevant AIP, with Differences from ICAO SARPs also notified there.
2.3.3.1 Section 91.703
says that you must comply with ICAO Annex 2 if you operate
your U.S.- registered aircraft “over the high seas.” Section 91.703 further
requires that you, when within a foreign country, follow the rules “relating to the flight and maneuver of air craft there in force.”
2.3.3.2 According to §§ 121.11, 125.23(b) , and 135.3(a)(2) , for operations under each
respective part, when operating within a foreign country, you must comply with the air traffic rules of the c ountry concerned and any local airport rules
that may be in force. You must also follow all rules of that part that are more
1 Exception: § 91.703 imposes the following subpart B flight rules for operations of civil aircraft of U.S. registry
over the high seas : §§ 91.117(c) , 91.127 , 91.129 , and 91.131 .
2 In addition, 14 CFR contains three flight and maneuver regulations (listed in footnote 1) which apply to operations
of civil aircraft of U.S. registry over the high seas.
10/4/23 AC 91 -70C
2-5 restrictive than the rules of the foreign country in which you are operating, as
long as you can do so without violating the rules of that country.
Note: In some countries, Annex 6 fuel requirements are in force,
which may be more restrictive than applicable 14 CFR rules.
2.3.4 Differing Airspace Requirements . It is quite possible to transit regions with significantly
different procedures in one long-range flight. Therefore, you should familiarize yourself
with the equipment and procedural requirements to file and fly in each segment of foreign airspace in which you intend to operate by referencing, for example, the appropriate State’s AIP.
2.4 ICAO Guidance Documents and Reference Material.
Find the following ICAO
documents at the ICAO store at https://store.icao.int.
2.4.1 Guidance Documents. We developed much of the material in this AC from these
foundational documents: ICAO Annexes, other ICAO guidance documents, related sections of 14 CFR, and other FAA guidance material.
2.4.2 Chicago Convention. We single out the following articles of the Convention on
International Civil Aviation (listed in ICAO Doc 7300) because of their importance in regulating international aviation. If you operate in oceanic and remote continental airspace, you should thoroughly understand them.
• Article 1, Sovereignty.
•
Article 12, Rules of the Air.
• Article 29, Documents Carried in Aircraft.
2.4.3 ICAO Publications . T he principal purpose of ICAO publications is the “systematic and
prompt dissemination in concise form of the policies and activities of the
Organization…” These publications consist of Annexes, documents with “Procedures for Air Navigation Services ” and “Regional Supplementary Procedures” in the name,
manuals, and other similar publications. The following is a brief description of each category of publications, beginning with the most authoritative, and moving down the hierarchy.
2.4.3.1 An
nexes. There are 19 Annexes (named in paragraph 2.2 above) to the
Convention on International Civil Aviation (listed in ICAO Doc 7300). They
state the SARPs.
2.4.3.2 Pro cedures for Air Navigation Services (PANS) and Regional
Supplementary Procedures (SUPPS) . ICAO publications with “Procedures
for Air Navigation Services” in the title have special status, as does the
publication “Regi onal Supplementary Procedures.”
2.4.3.2.1 ICAO Doc 4444, Procedures for Air Navigation Services—Air Traffic
Management (PANS -ATM) . These procedures complement the SARPs
10/4/23 AC 91 -70C
2-6 contained in ICAO Annex 2 and Annex 11, and specify, in greater detail than
in the SARPs, the actual procedures A ir Traffic Service (ATS) units apply
when providing various services to air traffic.
2.4.3.2.2 I CAO Doc 8168, Procedures for Air Navigation Services—Aircraft
Operations (PANS -OPS) . This document has three volumes:
1. Volume I, Flight Procedures , describes operational requirements for flying
the procedures designed in accordance with the criteria provided in
Volume II.
2. Volume II, Construction of Visual and Instrumental Flight Procedures, is
intended for the guidance of procedures specialists and describes the
essential areas and obstacle clearance requirements for the achievement of
safe, regular instrument flight operations. It provides the basic guidelines to States, and those operators and organizations producing instrument flight charts, that will result in uniform practices at all aerodromes where instrument flight procedures are carried out.
3. Volume III, Aircraft Operating Procedures, describes operational procedures recommended for the guidance of flight operations personnel and flightcrew.
2.4.3.2.3 I
CAO Doc 7030, Regional Supplementary Procedures. For each ICAO region,
ICAO Doc 7030 provides detailed procedures designed to meet those needs of specific areas that are not covered in the worldwide provisions contained in the Annexes and PANS documents. The SUPPS complement the statement of requirements for facilities and services contained in the Air Navigation Plan publications.
Note: T
o illustrate the hierarchy among ICAO publications, we can
look at the topic of communication failure. ICAO Annex 2 details
global procedures on communication failure. ICAO Doc 4444 elaborates on those procedures, which, “unless otherwise prescribed on the basis of regional air navigation agreement,” are in effect. ICAO Doc 7030 describes such regional agreements. FAA principal inspectors (PI) and spec ialists within the FAA’s Flight Technologies
and Procedures Division, Flight Operations Group can help you understand the relationship between various ICAO publications.
2.4.3.3 Manuals. Similar to our ACs, ICAO manuals provide guidance and
information concerning selected aspects of aeronautical activity or facilitating
the uniform application of ICAO SARPs. Therefore, you should familiarize yourself with the following documents (current editions) prior to undertaking operations in oceanic and remote continental ai rspace. The following are the
more prominent ICAO manuals:
10/4/23 AC 91 -70C
2-7 2.4.3.3.1 I CAO Doc 9574, Manual on a 300m (1,000 ft) Vertical Separation Minimum
Between FL 290 and FL 410 Inclusive. ICAO Doc 9574 provides States’
regional planning groups with a basis for the revision of documents,
procedures, and programs to enable the maintenance of a 300m (1,000 ft) vertical separation minimum between flight level (FL) 290 and FL 410 inclusive, in accordance with the criteria and requirements developed by ICAO. It provides guidance to S tate aviation authorities on those measures
necessary to ensure that the criteria and requirements are met within their area of responsibility, as well as background information for operators to assist in the development of operating manuals and flightcrew procedures.
2.4.3.3.2 ICAO Doc 9613, Performance-based Navigation (PBN) Manual .
This manual
provides practical guidance on how to implement Area Navigation (RNAV) and Required Navigation Performance (RNP) applications, and how to ensure that the performance require ments are appropriate for the planned application.
2.4.3.3.3 ICAO Doc 9869, Performance-based Communication and Surveillance
(PBCS) Manual. This guidance material explains the concepts of Required
Communication Performance (RCP) and Required Surveillance Performance
(RSP), identifies RCP and RSP requirements applicable to the provision and use of ATS, and provides a basis for the application of RCP and RSP in a specified airspace.
2.4.3.3.4 ICAO Doc 10037, Global Operational Data Link (GOLD) Manual. The
GOLD Manual addresses d ata link service provision, operator readiness,
controller and flightcrew procedures, performance -based specifications, and
post-implementation monitoring and analysis. GOLD provides guidance and information concerning data link operations and is intended to facilitate the
uniform application of ICAO SARPs contained in ICAO Annex 2, Annex 10,
and Annex 11; the provisions in ICAO Doc 4444; and, when necessary, ICAO Doc 7030.
2.4.3.3.5 I
CAO NAT Doc 007, North Atlantic Operations and Airspace Manual. This
document provides information for aircraft operating agencies, pilots, and
dispatchers planning and conducting operations in or above the North Atlantic High Level Airspace (NAT HLA). It also offers guidance to the State regulators responsible for the approval/certification/licensing of such aircraft
operators, pilots, or dispatchers.
Note: O
perators flying below NAT HLA should pay particular attention to ICAO NAT Doc 007, Chapter 17, Flight Operations Below
the NAT HLA. Information in the North Atlantic International General Aviation Operations Manual (NAT IGA) was incorporated into ICAO NAT Doc 007 in 2013.
10/4/23 AC 91 -70C
2-8 2.4.4 O ther References:
1. ICAO Satellite Voice Guidance Material (SVGM), available at
https://www.icao.int/apac/d ocuments/edocs/cns/satvoice_svgm_v1.pdf . This
document is intended to maximize the operational benefits of SATVOICE
implementations by promoting seamless and interoperable SATVOICE operations throughout the world. The document provides guidance and information concerning SATVOICE communications for aeronautical use and is intended to facilitate the uniform application of ICAO SARPs contained in ICAO Annex 2, the provisions in ICAO Doc 4444, and, when necessary, ICAO Doc 7030.
2. T
he FAA w ebsite at https://www.faa.go v.
3. Resource Guides for United States Operators:
a. North Atlantic (NAT) Resource Guide for U.S. Operators at
https://www.faa.gov/headquartersoffices/avs/nat-resource-guide .
b. Pacific Resource Guide for U.S. Operators at https://www.faa.gov/headquartersof
fices/avs/ pacific-resource-guide .
c. West Atlantic , Gulf of Mexico, and Caribbean Resource Guide for U.S. Oper ators
at https://www.faa.gov/headquartersoffices/avs/ wa t-gomex-and- caribbean -
resource-guide .
Note: Contact information for specialists from the Flight Operations Group can
be obtained from the responsible Flight Standards office, and is avai lable in these
resource guides.
4. Applicable FAA Domestic/International Notices and Notices to Air Missions
(NOTAM) .
5. U.S. AIP and applicable foreign AIPs. The AIP is the State’s official publication that
defines and describes the airspace, aeronautical facilities, services, and national rules
and practices pertaining to air traffic, particularly if they differ from ICAO SARPs
(“differences” are listed in AIPs). Eurocontrol maintains a global listing of links to AIPs here: https://eurocontrol.int/articles/ais -
online . Refer to the current AIP for any
States whose airspace you intend to operate in/through.
6. R egulations of the foreign countries over which you intend to fly.
7. The customs procedures, cultural considerations, entry and overflight procedures, and
health and safety precautions for each country in which you intend to land.
8. The “Oceanic and R emote ” section of the FAA’s Flight Operations Group web page
at https: //www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs4
00/afs410/oceanic_remote. See in particular the “ Ocean ic and Remote Continental
Application Guide” posted there.
9. Th e “Data Communications” section of the FAA’s Flight Operations Group
web page, at https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/a
fx/afs/afs400/afs410/datacomm/ . See in particular the “Data Link Communication
Application Guide” posted there.
10/4/23 AC 91 -70C
2-910.NAT bulletins, found in the “EUR and NAT Documents” area of the ICAO website:
https://www.icao.int/EURNAT /Pages/EUR -and- NAT -Document.aspx.
2.5 Authorization to Operate in Oceanic/Remote Continental Airspace and Special
Areas of Operation (SAO). The FAA requires all certificated U.S. operators to obtain
operational authorization to fly in oceanic and/or remote continental airspace .3 The FAA
requires all operators to obtain operational authorization to fly in some or all SAOs.
SAOs are areas with unique characteristics that require special equipment, procedures, and/or techniques. The Administrator grants authorization in the form of an OpSpec, a management specification (MSpec), or a Letter of Authorization (LOA), depending on what part of 14 CFR governs your operations.
2.5.1 Appendix B , Special Areas of Operation and OpSpecs/MSpecs/LOAs, provides more
information on SAOs, related authorizations, and other operational authorizations pertaining to oceanic, remote continental, and en route operations.
2.5.1.1 T
able B-1, SAO -R elated OpSpecs/MSpecs/LOAs, lists SAOs that require
authorizations, broken down by part.
2.5.1.2 T able B-2, O ceanic and Remote/General En Route OpSpecs/MSpecs/LOAs,
lists operations that require authorizations, broken down by part.
2.5.2 P art 91 operators only require authorizations as indicated in the footnotes to Tables B-1
and B-2.
2.6 Authorization Process. The FAA uses a five-phase process to approve operator
applications. The responsible Flight Standards office can provide you with the details
pertinent to each phase and your specific requirements.
2.6.1 P hase 1 . You determine a need for authorization and contact the FAA.
2.6.2 Phase 2 . You formally submit a proposal for FAA evaluation.
2.6.3 Phase 3 . We evaluate the request and determine what level of demonstration is required.
We may conduct the demonstration within the responsible Flight S tandard s office, at
your site of operations, or at another suitable location.
2.6.4 Phase 4 . W e observe and evaluate a demonstration of your ability to perform in
accordance with your proposal. This is an operational evaluation. If the demonstration is unsuccessful, we will provide feedback on deficient areas and their resolution.
3 Certificated operators holding OpSpec B032 /MSpec B031 , En Route Limitations and Provisions, do not need
OpSpec /MSpec B036, Oceanic and Remote Continental Navigation U sing Multiple Long -Range Navigation
Systems, provided they adhere to the OpSpec B032 /MSpec B031 limitation of being able to obtain a “reliable fix”
at least once each h our from a standard IC AO ground -based Navigational Aid ( NAVAID ).
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2-10 Note: Flight or line observations are not required for GA LOA applications. For
GA operators, we evaluate your application and if warranted, conduct a
knowledge validation (tabletop exercise and/or static airplane demonstration).
2.6.5 P hase 5. If your demonstration is successful, we issue the requested
OpSpec/MSpec/ LOA.
2.7 We b- Based Operations Safety System (WebOPSS).
2.7.1 Web OPSS Access. WebOPSS is the FAA’s document management system for issuing
OpSpecs, MSpecs, and LOAs to air operators as indicated in 14 CFR. Authorized aviation industry personnel can apply for access to WebOPSS through their PIs. WebOPSS access allows industry personnel to vi ew and propose changes to their
authorizations, which can expedite applications.
2.7.2 WebOPSS Training . Y
ou will require training prior to receiving WebOPSS access. You
can accomplish the training either through an FAA inspector or by taking the WebOPSS formal training course through the FAA’s Mike Monroney Aeronautical Center (MMAC).
Note: T
he Operations Approval Portal System (OAPS) was introduced late 2018 to streamline processing of NextGen authorizations. OAPS allows bundling, and is integrated with W ebOPSS. To register for an account, follow instructions on
the web page: https://oaps.faa.gov/ . For s
upport and/or questions, email
9-AWA- AVS -AFS-OAPS@faa.gov.
10/4/23 AC 91 -70C
3-1 CHAPTER 3. PILOT QUALIFICATION AND TRAINING GUIDANCE FOR OCEANIC
AND REMOTE CONTINENTAL AIRSPACE OPERATIONS
3.1 Training Requirements for Oceanic and Remote Continental Airspace Operations.
3.1.1 Certificated Operator Training . Certificated operators are required to have training
approved by the Admin istrator.4 This normally takes place during the certification
process and prior to issuance of OpSpecs or MSpecs.
3.1.2 GA Training . If you are a GA pilot desiring to indicate RNP capability in oceanic and
remote continental airspace, you need operational approval via an LOA (see Appendix B,
paragraph B.1).5 One or more of the following actions may satisfy training requirements:
1. Completing an operator’s oceanic operations current training program.
2. Completing a commercial oceanic operations current training program.
3. Submitting military training records indicating prior oceanic operations experience.
4. Using other methods indicating that you can safely conduct oceanic operations.
Examples could include written testing, oral testing, or evidence of prior recent experience.
3.1.3 Relevant Subject Matter . The follow ing items are examples of the subject matter with
which you should be familiar in order to conduct operations in oceanic and remote continental airspace (as required based on the types of operations being conducted):
1. Title 14 CFR (applicable parts).
2. ICAO S ARPs and measurement standards.
3. Operator’ s international operating procedures, to include the international operations
manual,6 its organization and structure, and access via E lectronic F light B ag (EFB),
as applicable.
4. Use of oceanic flight planning chart s.
5. Sources and content of int ernational flight publications.
6. Itinerary planning and overflight clearances.
7. Meteorology, including S ignificant Weather (SIGWX) charts, prognostic weather
charts, tropopause prognostic charts, and Terminal Aerodrome Forecasts (TAF), as
well as contingency procedures for weather diversions.
8. Preparation of international flight plans, plotting charts, and operational flight plans (OFP) /flight logs, to include Equal Time Point (ETP ) calculations. These include the
4 Regulatory references are §§ 91.1073, 121.401 , 125.296 , and 135.323 .
5 Regulatory reference is § 91.703 , which incorporates ICAO Annex 2 by reference. Annex 2, in turn, refers to
ICAO Doc 7030 , which requires State of the Operator or State of Registry approval for oceanic RNP operations.
6 See also Appendix G , Suggested Subjects for Inclusion in Oceanic and International Procedures and/or an
Operations Manual.
10/4/23 AC 91 -70C
3-2communications, navigation, and surveillance capability codes appropriate to your
aircraft and your operational authorization.
9. Specific airspace requirements, to include communications, navigation, and
surveillance equipmen t requirements a nd specific approvals
(OpSpecs/MSpecs/LOAs), as well as operational procedures related to ReducedVertical Separation Minimum (RVSM) and RNP.
10. Long- range, air -to-ground communication procedures, including all data link and
satellite communic ations (SATCOM) voice operations, as applicable.
11. En route and terminal procedures—differences from U.S. procedures.
12.Use of oceanic checklists.
13.Oceanic error risk mitigations.
14.Understanding of Strategic Lateral Offset Procedures (SLOP).
15.Air traffic clearanc es, to include proper terminology and phraseology.
16. Emergency and contingency procedures (see Appendix F , Special Procedures for
In-Flight Contingencies in Oceanic Airspace), includ ing required emergency
equipment, SAR techniques, navigation equipment failure techniques (to include dead
reckoning (DR) ), and communication equipment failure techniques.
17.Specialized training, ( e.g., if conducting operations in areas of magnetic unreliabi lity
(AMU), or for parts 121 and 135, ETOPS “preclude and protect” philosophy, as
applicable).
18.Use of polar/remote area checklists.
19.P
olar/remote continental terrain awareness, risk mitigations, and contingency options.
10/4/23 AC 91 -70C
4-1 CHAPTER 4. COMMUNICATIONS, NAVIGATION, AND SURVEILLANCE
SYSTEMS GUIDANCE FOR OPERATIONS IN OCEANIC AND REMOTE
CONTINENTAL AIRSPACE
4.1 Communications, Navigation, and Surveillance Improvements—Impact on ATS.
4.1.1 Technological Advances. Technological advances in communications, navigation, and
surveillance systems al l contribute to an air traffic system that provides increased
navigational accuracy and allows you and your aircraft to interact more quickly with
controllers. These advances have also improved controller-pilot communications, navigation accuracy, and airc raft surveillance reporting. This enhanced communications,
navigation, and surveillance capability greatly reduces the errors and retransmissions that hampered oceanic flights just a few years ago. These safety improvements have facilitated corresponding i mprovements in efficiency and capacity by reducing separation
minima, allowing controllers to space aircraft closer together. Trials of new separation minima or implementations of new operating procedures are common in oceanic airspace. Operators should therefore make sure they have the most up- to-date information
concerning the airspace in which they will be flying. U.S. and foreign State AIPs, NOTAM s, and related publications are normally the best sources of current information.
International ope rations manuals that consolidate this information should be current.
4.1.2 ADS -B.
ADS -B supports these improvements by providing a higher update and enhanced
accuracy of surveillance information over the current radar -based surveillance systems.
4.1.3 S pace- Based ADS -B. In 2019, a constellation of low-E arth orbit satellites with ADS -B
receivers began supplying surveillance data to air traffic service providers (AT SP).
Shortly thereafter, ICAO published a new separation standard for areas under ADS- B
surveillance where VHF voice communications are not available. This new separation
standard allows aircraft to be more close ly spaced in oceanic areas, which in turn allow s
more efficient routing. While space -based ADS -B update rates are comparable to those of
some domestic radar systems, communication systems traditionally used in oceanic and remote continental airspace do not perform as quickly as the VHF voice communications used in domestic environments. Consequently, aircraft cannot yet be spaced as closely as in domesti c areas. As communication systems evolve, allowable separation between
aircraft will likely be reduced further.
4.2 Performance-b ased Operations.
4.2.1 Measures of Performance. Performance-based operations rely on RCP, RNP, and RSP. It
uses these three primary measu res of performance to determine required separation
between flights, both in radar contact and in oceanic and remote continental airspace. ATS providers determine separation requirements based on a combination of these three performance indicators.
4.2.2 RCP . R
CP establishes aircraft/controller communications timeline, equipment, and
flightcrew training standards. Generally, you can measure RCP in terms of the timeline required to complete the communication transaction and the continuity, availability, and
10/4/23 AC 91 -70C
4-2 integrity of the transaction. In oceanic and remote continental airspace, RCP 240 and
RCP 400 are the prevalent performance standards.
4.2.2.1 RCP 240 requires a 99.9 percent probability (continuity) the communications transaction will complete in less than 240 seconds (timeline). It also requires a 99.99 percent probability the communication can be initiated (availability) and no more than 10
-5 communications transaction malfunctions per flight-hour
(integrity).
4.2.2.2 RCP 400 requires a 99.9 percent probability (continuity) the communications transaction will complete in less than 400 seconds (timeline). It also requires a 99.9 percent probability the communication can be initiated (availability) and no more than 10
-5 communications transaction malfunctions per flight-hour
(integrity).
4.2.2.3 U.S. operators desiring Performance-based Communications and Surveillance (PBCS) approval for qualifying systems (e.g., with RCP 240 and RSP 180) can obtain OpSpec/MSpec/LOA A056, Data Link Communications. See paragraph 4.5
below.
4.2.2.4 For additional details, please refer to AC 90-117 , Data Link Communications ;
and the ICAO Doc 10037, Global Operational Data Link (GOLD) Manual, Appendix B, RCP Specifications, and ICAO Doc 9869, Performance-based
Communication and Surveillance (PBCS) Manual, at
https://store.icao.int .
4.2.3 RNP . RNP establishes aircraft navigation accuracy, equipment, and flightcrew training
standards. ICAO Doc 9613 , Performance-based Navigation (PBN) Manual, outlines these
standards. Generally, we measure these standards in terms of accuracy, integrity, continuity, availability, and functionality. Oceanic and remote continental airspace ATS providers primarily provide RNP 10 (also known as RNAV 10) and RNP 4- based
separation minima. RNP 2 applications have also become available for oceanic and remote continental airspace, to be used by individual States as necessary to meet their airspace requirements. In all cases, ATS providers will apply appropriate separation minima between adjacent aircraft based on the capabilities each aircraft operator files in the flight plan. You must only indicate the oceanic RNP capability authorized in your OpSpec/MSpec/LOA B036, Oceanic and Remote Continental Navigation using Mul tiple
Long- Range Navigation Systems.
1. RNP 10 requires accuracy to be within 10 NM 95 percent of the time.
2. RNP 4 requires accuracy to be within 4 NM 95 percent of the time and within 8 NM
99.999 percent of the time.
3. RNP 2 requires accuracy to be within 2 NM 95 percent of the time and within 4 NM
99.999 percent of the time.
7 Regulatory reference is § 91.169 , which refers to § 91.153 . This requires the flight plan to include “any other
information the pilot in command (PIC) or ATC believes is necessary for ATC purposes.”
10/4/23 AC 91 -70C
4-3 Note: Regardless of RNP value, pilots are expected to fly the centerline (or up to
2 NM right of course, where use of SLOP is authorized).
4.2.4 RS P . RSP establishes aircraft/controller surveillance timeline and equipment standards.
Generally, you can measure RSP in t erms of the timeline required to complete the
transaction and the continuity, availability, and integrity of the transaction. In oceanic and
remote continental airspace, RSP 180 and RSP 400 are the prevalent performance standards.
4.2.4.1 R
SP 180 requires a 99 per cent probability (continuity) the surveillance
transaction will complete in less than 180 seconds (timeline). It also requires a 99.99 percent probability the communication can be initiated (availability) and no more than 10
-5 communications transaction ma lfunctions per flight -hour
(integrity).
4.2.4.2 RSP 400 requires a 99 percent probability (continuity) the surveillance transaction will complete in less than 400 seconds (timeline). It also requires a 99.9 percent probability the communication can be initiated (a vailability) and
no more than 10
-5 communications transaction malfunctions per flight-hour
(integrity).
4.2.4.3 For additional details, please see ICAO Doc 10037, Appendix C, RSP Specifications.
4.2.5 A
ccess to Performance -based Separation . Communications, navigation, a nd surveillance
capabilities of aircraft and crew determine eligibility for authorizations (i.e., via OpSpecs, MSpecs, and LOAs), which in turn allow operators to take advantage of performance- based separation in oceanic and remote continental airspace. Th e significant
improvements in communications, navigation, and surveillance systems have allowed air traffic controllers to reduce separation between aircraft, expanding access to more favorable routing and/or altitudes that offer savings in time and fuel.
Note: F
or a list of pertinent OpSpecs/MSpecs/LOAs, please see Appendix B ,
Special Areas of Operation and OpSpecs/MSpecs/LOAs.
4.3 V oice Communications in Oceanic Airspace. When operating over the high seas,
ICAO Annex 2 requires you to m aintain a continuous air- to-ground voice communication
watch with the appropriate ATS authority on the appropriate communication channel.
Note: It is not acceptable to depend solely on other aircraft providing a radio relay
to satisfy this requirement. The appropriate authority for the airspace where you
conduct the flight may prescribe the aeronautical stations and frequencies used for two-way communications.
4.3.1 H
F Radio Communications. HF radios have been in use for almost a century over oceanic
and remote continental areas. As technological advances lead to more sophisticated methods of communication, HF equipment has also improved. HF radios now offe r
digital tuning, compact size, selective calling systems (SELCAL) (see paragraph 4.3.2
10/4/23 AC 91 -70C
4-4 below), and new antenna concepts. Consider the following when using HF
communications:
4.3.1.1 HF radio calls are typically made to a radio operator, who in turn
electronically relays the information, via keyboard and pre- formatted
messages, to air traffic controllers in oceanic centers. There is some delay between your requests and ATC clearances, where the radio operator coordinates with the appropriate controller. Radio operators do not have the authority to issue ATC clearances on their own.
4.3.1.2 Communications over HF radio rely heavily on proper radio terminology and scripted reports. Use the published guidance found in en route publications or the Aeronautical Information Manual (AIM)
to make sure you deliver
messages in the proper format. Speak at a moderate speed using the internationally accepted phraseology. You may find ICAO standard phraseology in ICAO Doc 9432, Manual of Radiotelephony. This document and other ICAO reference materials are available on ICAO’s website at
https://store.icao.int .
4.3.1.3 If ATC uses the terms “expect” or “when can you accept ,” they have not
granted you a clearance. Typically, oceanic radio operators will use the phraseology “ATC clears…” when relaying a clearance.
4.3.1.4 ICAO Doc 4444
, Procedures for Air Navigation Services —Air Traffic
Management, requires the flightcrew to read back level instructions, heading
and speed instructions, and ATC route clearance s. Ensure that the radio
operator acknowledges your exact read back to confirm that you correctly heard the instructions.
4.3.1.5 In general, higher frequencies (above 10.0 megah ertz (MHz)) work better
during daylight and lower frequencies (below 10.0 MHz) at night. It is common to use several frequencies on one flight while communicating with the same ATS provider.
4.3.1.6 HF communications are dependent on transmitted signals striking the ionosphere and reflecting back to antennae at ground stations. The ionosphere is susceptible to interference from space weather, resulting in periods where HF reception is marginal or unreadable. You may especially notice this phenomenon in polar regions above 60° N or below 60° S and during periods of significant solar activity.
4.3.2 SELCAL. SELCAL is a means to alert an individual aircraft that a ground station wishes
to communicate with it. ATS providers can transmit SELCAL signals over VHF or HF. The signals produce an audio tone and possibly a cockpit indication that alerts you to initiate contact with the appropriate ATC unit.
4.3.2.1 The SELCAL codes are controlled by a commercial service and are assigned to a specific aircraft. Since the number of unique S ELCAL codes is less than
10/4/23 AC 91 -70C
4-5 the number of aircraft with SELCAL capability, multiple aircraft could be
operating and logged in with the same SELCAL code assignment.
4.3.2.2 When you apply for SELCAL codes for your aircraft, the issuing company will de -conflict duplica te codes by region as much as possible. However,
aircraft flying in multiple regions may encounter another aircraft using the same code. Therefore, y ou should be certain that the ATS radio operator uses
your exact call sign when responding to a SELCAL.
4.3.2.3 New SELCAL systems use 32 tones, instead of only 16 tones currently used, and thereby increase the number of unique identifiers exponentially. The ICAO Communication Panel approved the global imple mentation of
SELCAL 32 for revisions to take effect in Novembe r 2022. SELCAL 32
compliant equipment became available beginning in 2020. Operators with 16-tone HF SELCAL systems may continue to encounter a duplicate code situation.
4.3.2.4 Check HF SELCAL even when your CPDLC is working properly. You should do a SELCAL check prior to oceanic entry and then again at each control area (CTA) boundary. See the sample transcript of an HF SELCAL check below.
Sample Transcript of HF SELCAL Check
HF call from the air: “New York Radio, Airline 123, request SELCAL Check.”
Answer from the
ground: “Airline 123, New York Radio, roger.”
[SELCAL tones transmitted]
HF call from the air: [If successful]
“SELCAL check good, thank you!”
4.3.3 SATVOICE . In keeping with ICAO’s recognition of SATVOICE as a valid LRCS, the
FAA accommodates SATVOICE through arrangements with the recognized Aeronautical Mobile Satellite (Route) Service providers. The FAA currently restricts direct SATVOICE contact between th e pilot and FAA ATC to “distress and urgency
situations,” or other exceptional circumstances only. For oceanic communications with ATC via New York Radio and San Francisco Radio, relevant SATVOICE policy and short codes are published in the U.S.
AIP.
4.3.3.1 The FAA requires SATVOICE equipment supporting ATS communications to be installed in accordance with AC 20-150B
(or subsequent edition),
Airworthiness Approval of Satellite Voice (SATVOICE) Equipment Supporting Air Traffic Service (ATS) Communication.
8 Addi tional
8 Regulatory references are § 91.703 and ICAO Annex 2, paragraph 3.6.5.1. The U.S. AIP, in des cribing the
“appropriate communication channel,” invokes AC 20 -150B.
10/4/23 AC 91 -70C
4-6 r
equirements are listed in the U.S. AIP. Portable satellite phones are not
approved for normal and routine ATC communications.
Addi tionally, the FAA requires a SATVOICE Callback Check when pilots use
SATVOICE to communicate with ATC via New York Rad io or San Francisco
Radio. A sample transcript is here:
Sample Transcript of SATVOICE Callback Check
SATVOICE call from
the air: “New York Radio, Airline 123, request SATVOICE
Callback Check.”
For aircraft equipped with both Inmarsat and Iridium:
“… on Inmarsat/Iridium (as applicable) ”
Answer from the
ground: “Airline 123, roger , terminating call, will call you right
back”
New SATVOICE call
from ground: “Airline 123, New York Radio with your SATVOICE
Callback, how do you read?”
SATVOICE answer
from the air: “Loud and clear, SATVOICE Callback Check good, good
day!”
4.3.3.3 If SATVOICE is used (as authorized in the relevant AIP) as the sole voice
LRCS, for purposes of maintaining a continuous air- to-ground voice
communication watch with the releva nt ATS authority on the appropriate
communication channel, several important considerations apply:
1. Flightcrews should be thoroughly familiar with SATVOICE use, to
include the aural and visual alerts for incoming calls, call answering, display and selection of call priority, use of press -to-talk switches, call
setup with or without the avionics phone book, call preemption, and call termination.
2. Avionics (e.g., flight management computer (FMC)) phone books should be organized in a logical, easy- to-understand manner, and flightcrews
should have the appropriate number preloaded to facilitate rapid call setup with the relevant ATS authority. Calls should be managed to ensure a line is always available for an incoming “Operatio nal High” priority
(Priority 2/Q12) c all from the relevant ATS authority.
3. For purposes of compliance with 14 CFR requirements on numbers of LRCS, the FAA recognizes SATVOICE as an approved LRCS only in areas where the ground infrastructure supports SATVOICE as the “sole voice LRCS.” Such services are described in the relevant AIP. In areas
10/4/23 AC 91 -70C
4-7 lacking this designation, at least one operable HF (voice) radio is
required.9
4. A
s SATVOICE technology evolves, ensure that you comply with the
latest guidance. In the United States, see entry in the U.S. AI P, with new
changes published in the FAA’s International Notices. For additional guidance, refer to the FAA’s AIM, ICAO’s
Satellite Voice Guidance
Material (SVGM) , a nd/or the relevant AIP.
4.3.4 Changes to Communications Procedures. Information needed on initial contact with an
agency, radio frequencies, and other aspects of oceanic communications are changed frequently. Thus, it is important that you consult the appropriate AIP, international notices, current oceanic charts, and co mmercial en route publications for the most current
information.
• ICAO NAT Doc 007, North Atlantic Operations and Airspace Manual, describes
North Atlantic (NAT) operations, to include communication and navigation
procedures in NAT airspace. The NAT section of ICAO Doc 7030, Regional
Supplementary Procedures, cu rrently require s HF SELCAL checks, meaning that an
HF radio is required in NAT airspace.
• Commercially published navigation charts contain details of communication p
rocedures on inserted panels. Exercise some caution in using this reference, as they
may be on a different update cycle than the source documents and therefore could be not completely up to date.
4.4 CPDLC and Automatic Dependent Surveillance -Co
ntract (ADS -C). Data link
communications systems are widely used throughout the world and are normally used in concert with ADS -C systems that further improve ATS capability. CPDLC technology
improves communications between aircraft and ATS providers. CPDLC replaces most of
the often-challenging HF voice communications that were the only communication link with oceanic and remote continental airspace air traffic controllers for decades. With
CPDLC, you and the controller transfer ATC clearance requests and instructions digitally, reducing the likelihood of miscommunication. CPDLC compliant with RCP 240 is required to fly the most efficient routes in the NAT .
Note: In ADS -C, C = “Contract.” The controller sets up one or more electronic
contracts with your aircraft to automatically provide time -triggered (periodic)
and/or condition-triggered (e.g., deviation event) reports. In addition, a controller, at any time, can issue a “demand” contract for a single periodic ADS -C report.
4.4.1 Title 14 CFR Requirements for LRCS . F
or purposes of compliance with 14 CFR
requirements on numbers of LRCS (cited in paragraph 2.3.1 above) , the FAA recognizes
CPDLC that is compliant with RCP 240 as a n approved LRCS. Equipage with CPDLC
does not eliminate the requirement for at least one operable voice LRCS. This means t hat
9 Regulatory references are § 91.703 and ICAO Annex 2, paragraph 3.6.5.1. The applicable AIP describes the
“appropriate communication channel.”
10/4/23 AC 91 -70C
4-8 (as is mentioned in paragraph 4.3.3.3 , item 3) unless the relevant AIP authorizes
SATVOICE as a sole voice LRCS, at least one operable HF (voice) radio is required.
4.4.2 A ccess to Preferred Airspace. Since equipment like CPDLC and ADS- C improves the
efficiency with which aircraft in oceanic and remote continental airspace can be
controlled, such better- equipped aircraft are being better served through initiatives to
reserve preferred blocks of oceanic airspace for those aircraft. Preferred altitudes and routes around the world are more readily issued to aircraft equipped with robust communications, navigation, and surveillance capabilities.
4.4.3 F
AA Domestic CPDLC Use of Free Text in Route Uplinks . The FAA’s domestic flight
data processing systems automatically add so -called “Free Text” messages containing the
entire cleared route, to all route clearance change messages. This allows pilots to more readily see and understand the given change. However, oceanic systems do not do this. The result is that pilots accustomed to the FAA domestic display of route clearances could be confused when seeing an oceanic route uplink. Figure
4-1, Sample CPDLC
Route Uplinks, shows how a CPDLC route uplink might look if se nt from a U.S.
domestic system versus an oceanic system.
10/4/23 AC 91 -70C
4-9 Figure 4 -1. Sample CPDLC Route Uplinks
Data Link Systems —Operational Authorization to Use. We grant operational
authorization for operators to use Future Air Navigation System (FANS) data link (used
in oceanic areas and in the U.S.) by issuing OpSpec/MSpec/LOA A056, as appropriate.10
Note: OpSpec/MSpec/LOA A056 also applies to VHF datalink communications
in overland areas, such as Aeronautical Telecommunications Network (ATN)
Baseline 1 (B1) (formerly Link 2000+), used in European airspace.
10 AC 90 -117 provides information on OpSpec/MSpec/LOA A056.
10/4/23 AC 91 -70C
4-10 4.5.1 Oceanic Data Link Requires Authorization . U.S. operators (including part 91) must have
a data link authorization to file ATC flight plan capa bility codes J5 and/or J7 in oceanic
airspace.11 These codes denote Inmarsat and Iridium satellite communications capability,
respectively. You can find our guidance on the process and procedures for operational
authorization and aircraft data link system approval in the following documents:
• AC 20-140 , Guidelines for Design Approval of Aircraft Data Link Communication
Systems Supporting Air Traffic Services (ATS).
• AC 90 -117.
4.5.2 Data Link Requirements and Standards. You can consult ICAO Doc 10037 for additional
information on data link requirements and standards.
4.6 ATC in Oceanic and Remote Continental Airspace.
4.6.1 Procedural Airspace. In oceanic and remote continental airspace, ATC typically requires
position reports via voice or ADS-C, and controllers apply “procedural separation,”
spacing aircraft farther apart than in domestic “ATS surveillance airspace” (where radar or ADS -B surveillance is accompanied by VHF voice communication with ATC).
Space- based ADS -B provides significant improvements in surveillance, but without ATC
being able to issue a vector via VHF voice communications, required separation between aircraft is greater . In areas with space- based ADS -B surveillance that lack direct VHF
voice communications with the controller, ATC st ill therefore provides at least some
elements of procedural control.
4.6.1.1 In procedural airspace, ATC issues clearances and instructions providing separation vertically and horizontally, based on the specific aircraft equipment authorizations you indicate on your flight plan.
4.6.1.2 ATC monitors your compliance with the issued clearance. Your aircraft position reports are processed for conformance with the clearance. If your aircraft is equipped with ADS -C, it provides trigger alerting for lateral and
vertical deviatio ns.
4.6.1.3 In order to make this procedural separation work the way it is designed, you
must provide timely and accurate time estimates (estimated time of arrival (ETA)) and operate with strict discipline and adherence to ATC clearances and procedures, both normal and contingency.
4.6.1.4 Controllers manage longitudinal separation in procedural airspace by assigning speeds, either true Mach number or true airspeed. Proper separation
11 AC 90 -117 cites the regulatory basis for this requirement, which is § 91.123 .
12 ICAO Annex 2, paragraph 3.6.2.2d), says: “if the time estimate … changes in excess of 2 minutes from that
previously notified to air traffic services, … the flight crew shall notify the appropriate air traffic services unit as soon as possible.”
10/4/23 AC 91 -70C
4-11of aircraft is dependent upon pilots maintaining the speed assigned with the
clearance (not to be confused with the speed filed on the flight plan).
•If traffic conditions permit, the controller may permit variations. However,if a controller assigns a speed, compliance with that speed is mandatory.
•Even when a controller permits variations, ICAO Annex 2 spe cifies that
pilots must inform ATC of speed variations of Mach 0.02 or greater from
the current flight plan (current clearance).
4.6.2 ICAO Procedures for Specific Geographical Areas. You will find detailed procedures for
the applicable ICAO Region in ICAO Doc 7 030. When flying over the high seas
(international airspace, generally greater than 12 NM from the nearest shore), part 91,
§91.703 requires compliance with Annex 2. Annex 2, in turn, refers to Doc 7030. You
should consider ICAO Doc 7030 re gulatory.
4.6.3 U.S. ATS . Inf ormation on provision of ATS by the United States is available in FAA
Order JO 7400.11, Airspace Designations and Reporting Points. A lso refer to 14 CFR
part 71.
4.6.3.1 Domestic Airspace. (ICAO refers to this as “Contine ntal” Airspace). Along
the coast of the United S tates, dom estic A TC pr ocedures (with ra dar or
ADS -B surveillance and VHF communications) are applie d in U.S. Offshore
Airspace, g enerally ext ending as far as the useful range of radar and VHF
communications systems permits, approximatel y 150-200 N M from the coast.
Note : Domestic airspace generally includes sove reign airspace over
terrain and territorial w aters, a s well as the “high seas” airspace
beyond 12 NM from the coast with ATS surveillance and VHF
communications. As discussed in paragraphs 2.3.2 and 2.3.3, part 91
subpart B applies in U.S. sovereign airspace, and ICAO Annex 2
applies in “h igh seas” airspace.
Ocea nic Airspace. The United States provides ATS in oceanic airspace as
follows:
•Atlantic Ocean: New York, Miami, and San Juan Flight Information
Regions (FIR).
•Gulf of Mexico: Miami and Houston Oceanic CTAs/FIRs. Most of theGulf of Mexico is under ADS -B surveillance, with VHF voice
communications directly with the controller (above 18,000 ft mean sea
level (MSL)).
•Pacific Ocean: Oakland and Anchorage CTA/FIR.
•Arctic Ocean: Anchorage Arctic CTA/ FIR.
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4-12 4.6.3.3 Remote Continental Airspace. The United States provides ATS in remote
continental airspace as follows: Alaska Remote Continental Airspace:
Anchorage Air Route Traffic Control Center (ARTCC).
4.6.4 Advanced Technologies and Oceanic Procedures (ATOP). U.S. controllers use the ATOP
flight data processing system in the airspace of Oakland Oceanic, New York Oceanic,
and Anchorage Oceanic and Arctic FIRs.
4.6.4.1 Within this airspace, ATOP allows for establishing the separation minima for all pairs of aircraft along a cle ared profile, and provides aircraft profile
conformance monitoring and protection.
4.6.4.2 ATOP deciphers ATC flight plan information to determine wh at separation
standards may be applied to a particular aircraft based on filed aircraft equipage. Accordingly, you must notify ATC immediately if your
communications, navigation, and surveillance equipment capability degrades below that which you listed in your flight plan.
4.6.4.3 ATOP analyzes cleared routes of aircraft and alerts controllers of potential future conflicts (scalable to more than 2 hours ahead) with other aircraft.
ATOP also considers different separation standards applied by adjacent ATC facilities and can warn the controller when a conflict will occur based on the adjacent ATC facility’s requirements. This allows controllers to effectively plan for transitions to adjacent FIRs.
4.6.4.4 You can find specific information regarding ATC separation standards in FAA Order JO 7110.65
, Air Traffic Control. Additionally, trial periods where
new separation standards are being applied will be announced on the FAA’s International Notices
website .
4.7 Special Use Airspace (SUA).
4.7.1 Warning Area. A warning area, as defined in 14 CFR part 1, § 1.1 , is airspace of defined
dimensions extending from 3 NM outward from the coast of the United States that contains activity that may be hazardous to nonparticipating aircraft. The purpose of such a warning area is to warn nonparticipating pilots of the potent ial danger. A warning area
may be located over domestic or international waters or both.
4.7.2 P
rohibited Areas . ICAO Annex 2 specifies that these areas exist “above the land areas or
territorial waters of a State, within which the flight of aircraft is prohibited.”
13 Regulatory reference is § 91.169, which refers to § 91.153. This requires the flight plan to include “any other
information the pilot in command or ATC believes is necessary for ATC purposes.” The U.S. AIP states that pilots must “advise ATC” if equipment failures render the filed capability indicators inaccurate.
10/4/23 AC 91 -70C
4-13 4.7.3 R estricted Areas. ICAO Annex 2 specifies that these areas exist “above the land areas or
territorial waters of a State, within which the flight of aircraft is restricted in accordance
with certain specified conditions.”
Note: C arefully review charts for these types of areas when you plan your flight,
taking note of the area operating times and restrictions. You should also review applicable oceanic NOTAMs.
4.8 Air Defense Identification Zones (ADIZ). Title 14 CFR P art 99, Security Control of Air
Traffic, discusses defense areas and ADIZ. You can check part 99, the latest U.S. AIP, the latest AIM (c hapter 5, section 6), and all FAA NOTAMs Domestic/International to
ensure compliance with national security requirements in the ADIZ.
4.9 Wor
ld Geodetic System 1984 (WGS 84). ICAO and th e United States endorse the
WGS 84 or approved equivalent as the geodetic reference datum standard for air
navigation latitude and longitude coordinates. WGS 84 provides for a common geodetic reference system and a means to standardize aeronautical surveys and related products. You should determine in advance whether any countries you int end to fly over or into are
WGS 84-compliant. Information about WGS 84 compliance is often noted on chart s used
in terminal operations or on airfield diagrams. A State’s AIP generally notes compliance with WGS 84. Most areas of the world are listed as: 1) Unknown (U); 2) Partially Compl iant (PC); 3) Compliant (C); or 4) Noncompliant (NC) with WGS 84.
Note: Commercial charting vendors also post information on their websites about
specific countries and their compliance with WGS 84.
4.9.1 O
perations in Areas That Are Not WGS 84- Compliant. Flight manuals may include a
note for RNAV systems indicating that, for countries or terminal areas that are not
WGS 84-compliant, the crew should deselect the use of Global Navigation Satellite
Systems (GNSS), and use ground- based navigation aids for na vigation. You should be
familiar with your flight manual limitations as well as any country -specific procedures
published in State AIPs when flying in countries or terminal areas that are not WGS 84-compliant.
10/4/23 AC 91 -70C
5-1CHAPTER 5. FLIGHT PLANNING GUIDANCE FOR INTERNATIONAL AND
OCEANIC AND REMOTE CONTINENTAL AIRSPACE OPERATIONS
5.1 Lead Time Requirements.
5.1.1 P reparation . Your preparation for a successful oceanic and remote continental and/or
international flight, whether you fly large or small aircraft, starts with adequate training
and planning. The lead time required for planning varies depending on such things as
experience, training, and currency, as well as specific country requirements, and could exceed 30 days. Dispatch/flight locator departments of 14 CFR part 121 operators and
large 14 CFR part 135 operators w ith good familiarity and experience with such flights
can sometimes work with shorter lead times. Commercial flight planning companies used by 14 CFR part 91 and smaller part 135 operat o
rs can offer similar services.
5.1.2 Awareness. Ensure you are aware of current and special notices relating to entry and
overflight requirements for the countries on your itinerary. In most cases outside North
America and Europe, you obtain prior permission to land in or overfly a country directly from that country’s Civil Aviation Authority (CAA). You can also find information on immunizations, ports of entry, and other important requirements in the country’s AIP and in various commercial publications.
5.1.3 Verification .
You should allow enough lead time to ensure your planning is thorough,
complete, and correct. You should also cross -check and verify any flight planning
products against the appropriate source documents. By doing so, you could uncover potential errors before they result in a pilot deviation.
5.2 P
reparing an Itinerary.
5.2.1 Itin erary Factors . You should consider the following questions when developing your
itinerary:
1.Wh at airspace, routes, speeds, and altitudes, do I fly to get to my destination(s)?
2.Are there any terrain clearance concerns along those routes at those altitudes?
3.Is the flying time to suitable and available en route alternates from along those routes
and altitudes appropriate for the aircraft and operating part? (Plotting ETPs will help
answer this question. )
4.Are there any pitfalls I should be aware of from each State’s AIP?
5. What communications, navigation, and surveillance equipment and authorizations
must I have in order to f ly my intended routes and altitudes?
6.Will I be operating in a n SAO? Do I have the necessary operational authorization(s)
to do so? (See Appendix B , Special Areas of Operation and OpSpecs/MSpecs/LOAs,
Table B-1, SAO -R elated OpSpecs/MSpecs/LOAs.)
7.With regard to my GNSS equipment, are there any WGS 84 compliance issues incountries I intend to transit? (Paragraph 4.9 provides information on WGS 84.)
10/4/23 AC 91 -70C
5-2 8. What survival equipment must I have on board in order to fly my intended routes?
9. Are there suitable en route and destination alternates available in the event of an
emergency diversion at other than my intended en route altitude? Are there terrain clearance or oxygen considerations at those divert altitudes?
10. Does my preferred destination have instrument approaches and arrival and departure procedures that are compatible with my aircraft equipment and authorizations?
11. What crew rest requirements will I have for each destination?
Note: See paragraph 5.3 below regarding fatigue management issues.
12. Should I use a flight planning or dispatch service for my trip?
13. Have I reviewed the following:
• Oceanic error mitigation procedures?
• Oceanic flight planning, plotting charts, navigation, and waypoint procedures?
• My oceanic checklist?
• SLOP?
• En route procedures for all airspace I will pass through?
• Oceanic contingency procedures?
14. Are there specific pilot certification, type rating, and/or medical certificate
requirements for the countries I’ll be visiting? Are single -pilot operations authorized?
15. Will my intended rout e take me through areas of volcanic activity?
16. If my route takes me through polar areas, have I researched the risks inherent to operations on polar routes? (Paragraph 5.10 provides information on polar
operations.)
17. ETO PS c onsideration : Will I be operating more than 60 minutes (part 121) or more
than 180 minutes (part 135) from an Adequate Airport?
5.2.2 A dministrative, Country- Specific Issues an d Requirements . As part of your itinerary
preparation, asking the following additional questions can help you determine the country- specific issues/airspace requirements that might affect your international flight:
1. D
o I require overflight and landing permi ts for any of the airspace/airfields I will
transit?
2. How much will overflight and landing fees cost, and how do I pay for each airspace and destination I intend to transit (e.g., credit card, cash, local currency, U.S. currency)?
3. How much advance notification do I need to provide prior to arrival?
Note: All countries require some form of advance notification of arrival. You
should carry a copy of the advance notification, as well as confirmation that the
10/4/23 AC 91 -70C
5-3 notification was sent. This is particularly important for c ountries that do not
normally return approvals.
4. What are the availability, types, and duration of visas, tourist cards, and other
required entry documents for all countries I intend to visit, as well as those with potential alternate airports (in the event I have to divert)?
Note: Some countries require that you have a visa for the next country of entry
before departure, as well as proof of required immunizations for that country. You can obtain this information from the U.S. Department of State (DOS).
5. Are there prohibitions, restrictions, notices, and/or applicable travel advisories for
countries I intend to visit?
Note: The FAA’s website includes a special section on prohibitions, restrictions,
notices , and DOS travel advisories applicable to foreign countri es at
https://www.faa.gov/air_traffic/publications/us_restrictions/. This is a particularly
important aspect of your flight planning.
6. What is th e normal work week for countries I intend to overfly/enter?
Note: Understanding this will help you coordinate for visas and overflight/landing
permits. You can obtain this information from the DOS.
7. Are there any import regulations I need to consider, given the a mount of time I intend
to remain in the countries on my route?
Note: Aircraft that remain within the territorial limits of a country for an extended
period may become subject to import regulations and impoundment.
8. What hours are customs, immigration, and other services operational?
9. Do I intend to conduct any operations that might be considered “cabotage?”
5.2.3 Airport -S pecific Issues. Consider the following airport -specific issues when planning for
your overseas trip: 1. What time considerations can affect your trip?
•
Wha t is local time at each of my destination airports in terms of Coordinated
Universal Time (UTC)?
• What is local time at my original departure airport?
• Are there restrictions on operating at night in the countries I intend to transit?
• Do any of the airspaces /destinations I intend to transit require slot times?
2. Is a Prior Permission Only (PPO) number required for landing?
3. Do my preferred destination and alternate airfields have the appropriate grade of fuel
and other types of aircraft handling services availab le?
10/4/23 AC 91 -70C
5-4 4. Are maintenance services available at my destination airfields?
5. Should I bring spare parts for my aircraft?
6. Will I have lodging available at the destination?
5.3 Crew Fatigue.
5.3.1 Fatigue Management . International travel typically involves crossing time zones and
interrupting normal sleep patterns (circadian rhythm). Ensure you have a plan for how
you will manage fatigue for you and your crew.
5.3.2 Fatigue Management Strategies. AC 120-100 , Basics of Aviation Fatigue, discusses
strategies to mitigate the effects of fatigue and is an excellent resource. AC 120-103 ,
Fatigue Risk Management Systems for Aviation Safety, discusses the Fatigue Risk Management Systems (FRMS) prescribed in 14 CFR part
117. While part 117 does not
apply to all operators, we recommend you review both ACs as the contents cover issues that are important to all aircrews. Although a Fatigue Risk Management Plan (FRMP) is
only required for part 121 operators, the FAA recommends any operator who frequently conducts long-range flights to objectively assess the risks of flightcrew fatigue and
implement some form of a plan to reduce those risks.
5.3.3 Se
lf -Care and Time Zone Differences . Having a high level of physical fitness, using
caffeine strategically, and avoiding alcohol can help you adjust to time zone differences, allow your body to rest better, and help make you a more effective, safer operator.
5.3.4 P
reparing to Mitigate Fatigue . Inquire in advance about day sleeping or noise levels in
the location where you intend to get your crew rest. This will help your crewmembers know what challenges to good rest might lie ahead. You should also consider adding pilots for long -duration flights or those outside of normal sleep times. This will help
mitigate fatigue issues and promote safer flying.
5.3.5 S
leep Aids. Make sure you understand the restrictions on using sleep aids and the
importance of consulting an Aviation Medical Examine r (AME) prior to use. They will
advise you on the possible side effects of sleep aids. We have built a list of approved prescription sedative -hypnotic-type drugs approved for use under certain conditions.
• Information regarding pharmaceutical sleep aids is available on the FAA ’s website .
• This web site includes names of many popular sleep aids. It also includes the required
wait time after taking the last dose before you can fly (“pill to push” time).
5.4 Required Paperwork/Documentation. Whenever you fly into, from, or over foreign
territory, you must comply with that territory’s regulations. Ensure that you have al l
required entry documents available for presentation upon arrival; you may need to provide multiple copies of each.
10/4/23 AC 91 -70C
5-5 5.4.1 D ocumentation. Local authorities may ask to see the below-listed types of paperwork.
The Articles of the Chicago Convention specify those items marked with a double plus
sign (++).
5.4.1.1 A ircraft/Aircrew Documentation. It is important to note that you may be
responsible for additional documentation requirements that this list does not
include.
1. Airworthiness certificate.++
2. Aircraft registration ++ (some States do not allow temporary certificates).
3. Radio station license.++
• ICAO Annex 6 Part I requires that one member of the flightcrew hold
a valid radio telephone operator’s license “authorizing operation of the
type of radio transmitting equipment to be used.”
• T he European Union Aviation Safety Agency (EASA) has published
inspector guidance for its Ramp Inspections program that references
the requirement in Article 30 of the Chicago Convention at https://www.easa.europa.eu/sites/default/files/dfu/SAFA%20Ramp%2
0Inspections%20Guidance%20Material%20-%20Version%202.0.pdf .
Some operators have found it useful to create a ramp inspection binder for easy access to required documents.
• F
or U.S. domestic flights operating only on VHF, the Federal
Communications Commission (FCC) does not require the license.
4. Minimum equipment list (MEL) (or Master Minimum Equipment List (MMEL) if operator plans to operate under this option).
5. Airplane Flight Manual (AFM) with Weight and B alance (W&B)
information and metric conversion tables, if applicable.
6. Copies of aircraft and engine logbooks.
7. Import papers for aircraft of foreign manufacture.
8. OpSpecs/MSpecs/LOA s.
Note: Some countries require an OpSpec/MSpec/ LOA and/or an
airworthiness statement for certain operations.
9. Ownership papers.
10. Certificates of insurance, if applicable.
11. Authorization letters from the operating company or the aircraft owner (original signature required), if applicable.
Note: For privately owned aircraft where the owner is not on board,
many countries require a letter from the owner before they will allow operations within their country (you can find specific information on
10/4/23 AC 91 -70C
5-6 this letter and other requirements in the AIP of the countries
concerned).
12. Licenses.
13. Crewmember certificates.++
Note: Pay special attention to medical certificates, as expiration rules
vary from country to country; consult the AIP for those countries
where you intend to land.
5.4.1.2 Trip -Specific Documentation. The following information will change for
each flight, but should be available for authorities:
1. Passenger manifest, containing complete names of passengers and places
of embarkation and destinations of each.++
2. Cargo manifest and detailed declaration of the cargo, if carried.++
3. Copies of overflight and landing permissions.
4. General declarations.
5. Journey logbook, signed by the pilot in command (PIC). ++ ICAO Annex 6
identifies the components of the journey logbook as listed below. Consult the AIP for the country you are visiting for their particular requirement.
• Airplane nationality and registration.
• Date.
• Names of crewmembers.
• Duty assignments of crewmembers.
• Place of departure.
• Place of arrival.
• Time of departure.
• Time of arrival.
• Hours of flight.
• Nature of flight (private, aerial work, scheduled, or nonscheduled).
• Incidents and observations, if any.
• Signature of person in charge.
5.4.1.3 Personal Documentation for Crew and Passengers. When planning a trip to
or from a foreign country, ensure that all travelers have proper personal documentation (passports and visas, as required). You may find the requirements for individual countries at https://travel .state.gov/ .
10/4/23 AC 91 -70C
5-7 5.5 Entry to Foreign Airspace—Flight Plan vs. Formal Advance Permission.
5.5.1 P ermission for Airspace Entry . When the foreign ATS authority accepts your flight plan
and issues you a flight clearance, you have not necessarily received official approval for
entering that State’s airspace. The governing CAA may independently require permission for airspace entry, and your destination airfield may require permission as well.
5.5.2 Fligh t
Plans . Your flight plan provides advance notice of foreign airspace penetration and
facilitates effective ATC procedures. For some countries, your flight plan is the only advance notice required; other countries use your flight plan as a check against previously granted permission to enter national airspace.
5.5.3 S
tate AIPs . During your pre-trip planning, as noted in paragraphs 5.1.2, 5.2.1, and 5.2.2
above, consult the AIP for the States you will transit to determine any overflight/landing permits and whether prior permission is required. Ensure you allow plenty of lead time to
request and obtain all necessary permissions.
5.6 M
anaging Risk in Oceanic and Remote Continental Airspace Operations. Operators
should have a risk management process before conducting oceanic operations (per ICAO Annex 19, originally i
ssued in 2013). Many of the topics included in earlier portions of
this chapter should be included as elements of your risk assessment. Operators are strongly encouraged to research the information available on the FAA website, both from
the standpoint of oceanic operations planning, and risk management overall. Non- airline
operators are also encouraged to review the material specifically earmarked for airline operators. You can get good ideas from that infor mation.
Note: T
he Automated Mutual- assistance Vessel Rescue (AMVER) system,
sponsored by the U.S. Coast Guard (USCG), is a computer-based voluntary global ship reporting system used worldwide by SAR authorities to arrange for assistance to persons in distress at sea. The w eb addres s is:
https://www.amver.com/ . Operators conducting oceanic operations are
encouraged to be familiar with AMVER in case of a potential ditching. Once the operator notifies ATC of a possible ditching, all merchant vessels registered with AMVER and within 100 NM of the aircraft’s predicted ditching position will be notified.
5.7 W
eather Forecasts and Other Meteorological Planning.
5.7.1 N ational Weather Service (NWS). The NWS provides weather, hydrologic, and climate
forecasts and warnings for the United States, its territories, adjacent waters, and ocean areas. Part s 91 subpart K (part 91K), 121, and 135 operators must use an approved
weather source (i.e., NWS or FAA-approved).14
14 Regulatory references are §§ 91.1039, 121.101 , and 135.213 .
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5-8 5.7.2 Weather Sources. As representatives of the Administrator, Principal Operations
Inspectors (POI) may approve, via OpSpec/MSpec A010, Aviation Weather Information
(required for parts 91K, 121, and 135) the following weather sources:
• The NWS for the United States and its territories.
• U.S. and North Atlantic Treaty Organization (NATO) military observing sources.
• Meteorological offices or automated observations operated by ICAO Member States
(as long as the States subscribe to ICAO meteorological standards and practices (i.e., list no differences to ICAO Annex 3
)).
• Members of the World Meteorological Organization (WMO).
5.7.3 Enhanced Weather Information Systems (EWINS) . Many certificated operators utilize an
EWINS. EWINS are systems for gathering, evaluating, and disseminating aviation weather information, and for issuing weather reports and forecasts prepared by properly trained and qualified aviation meteorologists or aircraft dispatchers. Air carriers typically use a proprietary EWINS. Parts 91K, 121, and 135 operators require FAA approval via OpSpec/MSpec A010 to use EWINS.
5.7.3.1 Each carrier’s EWINS must have sufficient procedures, personnel, and communications and data processing equipment to effectively obtain, analyze, and disseminate aeronautical weather data. An EWINS source may produce weather analyses and forecasts based on meteorological observations provided by the Federal government.
5.7.3.2 For an explanation of EWINS, refer to FAA Order 8900.1
, Volume 3,
Chapter 26, Section 4, Enhanced Weather Information Systems. Approval to use EWINS weather products is issued on a case -by-case basis and is
currently only applicable to part 91K program managers and part 121 or 135
certificate holders (CH) , who may either act as their own EWINS or contract
for services from an outside source. These approved operators may conduct flight operations using the weather analyses and forecasts produced by their approved EWINS.
5.8 FAA In ternational Notices Website. International Notices include Flight Prohibitions
Notices and International Oceanic Airspace Notices that could affect your decision to enter or use certain areas of foreign or international airspace. If you are seeking to ente r
areas of the world that require special consid erations, these n otices can be very important.
To access FAA International N otices, refer to
https://www.faa.gov/air_traffic/publication
s/internationalnotices/.
5.9 ETOPS. ETOPS (the ICAO term is “Extended Diversion Time Operations (EDTO)” )
requirements pertain to aircraft operated under parts 121 and 135. ETOPS is a system of maintenance, planning, alternate airport selection, dispatch, and flight operations standards that are designed to preclude a diversion and, if one were to occur, to protect
15 Regulatory references are §§ 91.1039, 121.101, and 135.213.
10/4/23 AC 91 -70C
5-9 that diversion. Thus, ETOPS standards establish a higher level of performance
requirements and equipment monitoring.
Note: Rules covering ETOPS do not address operations conducted under part 91.
However, because risk increases with distance from an Adequate A irport (defined
in § 121.7), if you are a GA operator, we strongly recommend that your pilot
training, maintenance practices, flight planning, and any applicable dispatch
procedures follow the processes and procedures established in ETOPS regulations and guidance.
5.9.1 ETO
PS Guidance . Guidance pertaining to ETOPS is provided in AC 120-42, Extended
Operations (ETOPS and Polar Operations), and AC 135-42, Extended Operations
(ETOPS) and Operations in the North Polar Area. The regulatory basis for ETOPS requirements is provided by part 121 (§§ 121.161 and 121.374 and appendix P ) a
nd
part 135 (§ 135.364 and appendix G ).
5.10 Polar Operations. ACs 120 -42 and 135- 42 cover polar operations by aircraft operated
under parts 121 and 135 respectively. As noted in the ETOPS discussion above, we strongly recommend part 91 operators refer to these ACs if you fly a polar route. Other worthwhile sources of information include the Canada and Iceland AIPs and the Canadian Designated Airspace Handbook. The North Polar Area of Operations includes the area that lies north of latitude 78° N. The North Polar routes across Russia are shown
in the Russian AIP or in commercial charts for Eastern Europe and Eurasia. The South Polar Area of Operations includes the area south of latitude 60° S. Operators should contact a specialist from the F AA’s Flight Technologies and Procedures Division, Flight
Operations Group for advice on operational factors to consider when planning polar operations.
1. Relevant authorizations are:
a. OpSpec/MSpec B055, North Polar Operations.
b. OpSpec/MSpec B040, Operations in Areas of Magnetic Unreliability.
2. Operations in AMU s when using a Global Positioning System (GPS)-only
navigation- sensor for the flight management system (FMS) require careful analysis to
confirm that the FMS is receiving accurate and reliable heading info rmation.
5.11 Areas With Limited or No ATS ( Also C alled “ NO FIR” A reas). Two examples of
such areas are the boundary between Bodo Oceanic and Murmansk, and the area
southeast of Mazatlan's Oceanic FIR off the west coast of Central America.
5.11.1 P
art 91 Operators. While part 91 GA operators are not bound by the requirements below,
we recommend that they have a solid understanding of this information before attempting to operate in this type of airspace. If you intend to operate in advisory-only airspace, you are required, as you are for all flights, to become familiar with all available information
10/4/23 AC 91 -70C
5-10concerning that flight.16 Good familiarity with applicable operating procedures allows for
safe operations.
5.11.2 C ertificated Operators . To operate in uncontrolled information regions, certificated
operators must be issued OpSpec/MSpec A014, Spe cial E n Route IFR Operations in
Class G Airspace, in accord ance with § 91.1015; § 121.93; § 121.113; part 125, § 125.31;
or § 135.215, as applicable. In uncontrolled airspace, you w ill not have access to ATC,
air traffic advisory, flight information, and alerting se rvices. In approving routes outside
controlled airspace via OpSpec/MSpec A014, the Administrator makes a determination
that traffic density is such that an adequate level of safety can be assured. FAA inspectors will also evaluate whether you have acceptab le alternative means to ensure the following:
1. Y
ou can notify the appropriate organization in a timely manner should you require
SAR assistance.
2. You have a method to access changes in SIGWX information in a timely manner.
3.Those navigation facilities necessary for you to safely conduct the operation are
available and serviceable. You can receive updates regarding the serviceability of therequired Navigational Aids (NAVAID).
4.You have reliable in -flight information concerning other IFR aircraft operating near
your route of flight (e.g., Traffic Alert and Collision Avoidance System (TCAS)and/or ADS-B In). This could also include “broadcast in the blind” procedures andother “expected” practices (see Appendix E , IATA In -F
light Broadcast Procedure, as
well as ICAO Annex 11 ’s description of traffic information broadcasts by aircraft
(TIBA)).
5.12 R otorcraft Operations.
5.12.1 F AA and ICAO Requirements . The guidance on U.S. and International Regulations in
Chapter 2, Background Information for Operations in Oceanic and Remote Continental
Airspace, also applies to helicopter operations in oceanic and remote continental airspace.
5.12.2 O ffshore Helicopter Operations . AC 90-80, Approval of Offshore Standard Approach
Procedures, Airborne Radar Approaches, and Helicopter En Route Descent Areas, contains detailed information on offshore helicopter operations, both instrument and ATS surveillance (ADS -B or radar). It also provides instruction on how you can gain
authorization to conduct such operations.
5.12.3 Helicopter O
ffshore Instrument Operat ions. OpSpec/MSpec/LOA H104, Helicopter
Offshore Instrument Operations: Offshore Standard Approach Procedure (OSAP), Airborne Radar Approach (ARA), and Helicopter En Route Descent Area (HEDA) Operations, is available to authorize en route descent procedures under IFR.
16 Regulatory references are § 91.103 , Preflight action, and ICAO Annex 2, Ch apter 2, Applicability of the Rules of
the Air, Paragraph 2.3.2, Pre -Flight A ction.
10/4/23 AC 91 -70C
5-11 5.12.4 Helicopter Part 135 Proving and Validation Tests . Section 135.145 is relevant for
rotorcraft operations in oceanic and remote continental airspace. You may develop
proposed routes using NAVAIDs where you have adequate signal coverage available. In
areas where signal coverage is not available, you must provide a suitable means of navigation. We may require a validation test in VFR conditions to ensure that you are able to demonstrate adequate navigational performance for the route(s) before granting approval for your use of the route(s).
10/4/23 AC 91 -70C
6-1 CHAPTER 6. FLIGHT EXECUTION GUIDANCE FOR OPERATIONS IN OCEANIC
AND REMOTE CONTINENTAL AIRSPACE
6.1 General Information. The main focus of this guidance is operations in oce anic airspace.
The guidance is also applicable to some operations in remote continental airspace, where
LRCSs are used.
6.1.1 Checklists . In Appendix D , Sample Oceanic Checklist, we have included a sample
oceanic checklist tailored from the ICAO version, in both condensed and expanded
forms. The checklist is designed to encourage an orderly task flow and reduce oceanic
vertical, lateral, longitudinal, and timing navigation errors. Similar to the ICAO version, the checklist in this AC represents lessons learned from many years of flight in oceanic
airspace, along with internationally accepted best practices for such operati ons.
Note: Y
ou may tailor the abbreviated and expanded checklists to your specific needs and operational circumstances. Until you are experienced and familiar with all items on your tailored checklist, we recommend you refer to your expanded
checklist to ensure you follow the procedures in their entirety.
6.1.2 P
ilot Deviations—Common Causes. Technological advances in communications,
navigation, and surveillance equipment have enabled aircraft to operate with ever-improving precision and accuracy. However, despite these improvements in
capability, pilots continue to deviate from their current route clearances.
Note: Th
e NAT ICAO Region publishes the Oceanic Error Safety Bulletin
(OESB), which is an excellent resource for understanding how to prevent common errors. The current OESB can be found in the “EUR and NAT Documents” area of the ICAO website, in the “NAT OPS Bulletins” folder: https://www.icao.int/EURNAT/P ages/EUR -and- NAT -Document.aspx.
6.1.2.1 Large Height Deviation (LHD). An LHD occurs when an aircraft is 300 feet
or more off its assigned altitude. LHDs increase the risk of mid -air collision.
6.1.2.1.1 The most common causes of LHDs are:
1. ATC loop errors:
• Misunderstood or miscommunicated clearances.
• Inadequate ATC coordination.
2. Pilot deviations from assigned altitude:
• Following the flight plan rather than a clearance or revised clearance.
• Erroneous altitude programming in the FMS, such as a mistake in the
step-climb entry.
• Misinterpretation/misapplication of conditional clearances.
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6-2 • Improper execution of contingency procedures.
• Turbulence encounters.
6.1.2.1.2 Data indicates that a majority of crew -related errors involve misinterpretation
or misapplication of “conditional clearances.” Conditional clearances improve
the efficient utilization of airspace, allowing ATC to assign a ltitudes that
enable lower fuel burn. Event reports from ATC and flightcrews indicate that pilots misapply terms in the clearance such as “BY” or “AT”—terms, which have completely different meanings. See Table 6 -1 below for examples of
incorrectly applied conditional clearances.
Table 6 -1. Examples of Incorrectly Applied Conditional Clearances
CLEARANCE CREW ACTION CORRECT ACTION
Via CPDLC at 1714, crew
conditionally cleared, “maintain F340, at 1725 climb to and maintain F360, climb to reach F360 by 1735,
report level, due to traffic.” Crew initiated climb early,
reported (ADS-C) passing F354 at 1721. Crew should have delayed
commencing climb until 1725, and planned to reach F360 by 1735.
Via CPDLC, crew at F380,
cleared F390 to cross
66N040W level. Crew commenced climb to
F390 at 40W (Mode C). Crew should have initiated
climb prior to 40W in order
to cross 40W at F390.
Via CPDLC at 1945, crew
cleared maintain F330, at 1952 climb to and maintain F350, climb to reach F350 by
1957, report level F350. Reported (ADS -C) level at
F350 at 1948. Crew should have delayed
commencing climb until 1952, and planned to reach F350 by 1957.
Crew cleared 68/40 64/50
IRBIM F360 M083 via HF voice, crew recleared to descend af ter passing 65N to
be level F340 before 64N. Crew commenced descent at
6529N/4650W. Crew should have initiated
descent after passing 65N and levelled at F340 prior to 64N.
Crew cleared 66/30 65/40
63/50 IRBIM LOMTA F400 M081. Via CPDLC, crew cleared climb F410 to cross
65/40 level. Crew failed to climb as
cleared and crossed 65/40 at F400 (ADS- C). Crew should have initiated
climb prior to 65N in order to cross 65N at F410.
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6-3 6.1.2.1.3 Your training program should provide your flightcrew with procedures that
ensure all ATC clearances are complied with correctly, particularly clearances with en route restrictions such as changing FL s based on a coordinated time or
a specific geographic po sition.
Note: Per ICAO NAT Doc 007 , North Atlantic Operations and
Airspace Manual, when flying in NAT HLA, if your aircraft is not
using CPDLC/ADS -C, you must immediately report to ATC both
when leaving and reaching a new FL. Doing so can enable the controller to identify and intervene when you have misunderstood or misapplied your conditional clearance.
6.1.2.2 G
ross Navigation Error (GNE). The FAA defines GNE s as lateral
deviations from course of 10 NM or greater. (Previously, the threshold was 25 NM).
6.1.2.2.1 The majority of today’s GNEs arise from pilots flying a very precise track to the wrong position because they failed to properly update their navigation system to reflect their currently effective route clearance. This can also result
from a clearance or revised clearance that was incorrectly entered, misread, or misunderstood. Procedures to follow in the event of a revised clearance are included in paragraph 6.4.1.7. Examples of scenarios that have led to GNEs
are:
1. P oor management of the M aster D ocument, resulting in crews not
knowing the currently effective route clearance.
2. Incorrect waypoint entry procedures, particularly if the waypoints are not named and flightcrews must enter t he full latitude and longitude.
Note 1: We use the term “currently effective route clearance” to
describe what ICAO Annex 2 refers to as the “current flight plan,” or
the most recently issued ATC clearance.
Note 2: W aypoints entered via full latitu de and longitude can produce
misleading display names, with truncated or rounded minutes of latitude/longitude or longitude. For example, the following two points could have identical display names:
Waypoint Coordinates Avionics Display ID
5530N020W
(N55° 30’/W020°) N55W020
55N020W
(N55° /W020°) N55W020
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6-4 Note 3: Pilots should therefore always confirm the expanded
coordinates of undesignated significant points (i.e., unnamed
waypoints defined by geographic coordinates).
6.1.2.2.2 GNEs also result when the aircraft navigation mode is actually different from that assumed by the crew. This scenario typically occurs when the crew fails to return the flight guidance system to an RNAV mode (e.g., “ LNAV” ) after
using heading mode (e.g., “ HDG”) to maneuver the aircraft.
6.1.2.2.3 Although there are a number of causes of GNEs, pilot inattention has been the root cause of many navigational errors. ICAO NAT Doc 007, Chapter 14,
Guarding Against Common Errors, provides excellent lessons learned from evaluation of GNE incidents.
6.1.2.3 Longitudinal Errors. Longitudinal errors, in the form of failure to provide
updated ETAs, are another common navigation error and one that is easily preventable.
6.1.2.3.1 Deviations around weather can affect ETAs. ICAO Annex 2 requires you to provide ATC with an updated ETA when weather deviations cause the originally notified ETA to be inaccurate.
6.1.2.3.2 Per ICAO Annex 2, you must adhere to any assigned Mach number or airspeed. If you use Long Range Cruise (LRC) or Economy (ECON) modes,
you are operating in a constantly changing speed mode. Flying in these modes may not be compatible with maintaining a fixed ATC speed assignment.
6.1.2.3.3 When position reports are made by voice, ICAO Annex 2 requires you to report to ATS any change to your ETA in excess of 2 minutes, both for your
initial oceanic entry point as well as all required reporting points along your route of flight. (In the NAT region, the allowance for revised estimates is “3 minutes or more.”)
6.1.2.3.4 Discrepant wind data can result in inaccurate ETA computations. This can be particularly problematic if you are not flying at the flight- planned altitude or
have outdated winds loaded in your navigation system . You must diligently
monitor your ETA and main tain your assigned Mach number in order to
minimize these errors.
6.1.2.3.5 Navigation system -computed ETAs, particularly for more distant waypoints,
may be erroneous due to down track wind conditions, which the navigation system is not presently using to compute th e ETA. You should compare
navigation system estimates with the ETA calculated using the OFP prior to
reporting the ETA to ATC.
6.1.2.3.6 Automatic position reports delivered via ADS-C have greatly reduced the occurrence of longitudinal errors caused by inaccurate ET As. ATC establishes
an ADS -C periodic report interval appropriate for the longitudinal and lateral
10/4/23 AC 91 -70C
6-5 separation criteria being used. More frequent reports compensate for wind
discrepancies and provide ATC with accurate ETAs.
6.2 Flight Plan.
6.2.1 A TC Flight Plan .
6.2.1.1 ICAO Annex 2 requires you to file a flight plan for any flight that crosses international borders. IFR operations in oceanic airspace generally start at 6,000 feet. VFR operations at or below 5,500 feet must comply with all applicable regulations and foreign airspace requirements.
6.2.1.1.1 Even though you may legally conduct flights in oceanic and remote continental airspace under VFR, you will likely encounter instrument meteorological conditions (IMC ) at some point in your flight.
6.2.1.1.2 We therefore recommend that you file and fly under IFR on all oceanic
flights.
6.2.1.2 Proper completion of an ATC flight plan re lies on detailed knowledge of the
airspace you intend to transit, the airspace equipment requirements, and the required FAA authorizations (OpSpecs/MSpecs/LOAs). You also need to be thoroughly familiar with the equipment your aircraft has on board as listed in your filed flight plan. When you file, your flight plan is transmitted to ATS facilities along the route of flight. If you do not file correctly, you could possibly e xperience delays before takeoff for an issue with an ATS authority
along your route of flight.
6.2.1.2.1 The AIM has a step -by-step description detailing how to complete FAA
Form 7233-4, Pre -F
light Pilot Checklist and International Flight Plan.
6.2.1.3 As Performance-based Navigation (PBN) and PBCS become more preva lent
worldwide, ATS authorities will increasingly set aside certain airspace for
compliant aircraft. You list your aircraft and crew capabilities using
descriptors in items 10A, 10B, and 18 of the flight plan.
Note: Without the proper codes or remarks identifyin g the operational
approvals of your crew and aircraft, controllers may deny you en route
climbs to your most fuel -efficient FLs or access to the optimum
routings or, in some cases, re ject your flight plan entirely.
6.2.1.4 Title 14 CFR part 121 dispatch services have staff knowledgeable in all filing
requirements for both domestic and international operations. These services can support flight plan reroutes that may arise due to weather or congestion along the route of flight. Regardless of whether you are operating with a
dispatch service, you must comply with 14 CFR part 91, § 91.103, which
requires pilots to “become familiar with all available information” concerning a flight. Pilots should have the knowledge and necessary tools available to
10/4/23 AC 91 -70C
6-6 react to unplanned reroutes, equipment failures, or emergencies that may
affect a flight while en route. Operators using commercial vendor flight
planning services remain responsible for all aspects of the flight.
6.2.2 E quipment Capability Codes —Flight Plan .
6.2.2.1 PBN and PBCS are changing the way ATS providers apply separation criteria between aircraft. Without notifying the crew of either aircraft involved, ATS providers in “mixed mandate” airspace can reduce separation between aircraft based on your stated capability. In order to take advantage of opportunities for more efficient routings, your flight plan should reflect the lowes t (i.e., the
best) RNP, RCP, and RSP values for which you are capable and authorized. You must only use codes for equipment that is installed and operable. Similarly, you must only use capability codes that reflect your actual authorizations, when authorization is required. You must have a specific approval (OpSpec/MSpec/LOA) to indicate RNP 2, 4, or 10 capability on your flight plan.
17 Conversely, you do not require an LOA for RNAV 1 or 2.
6.2.2.2 The absence of equipment or capability codes in your flight plan (e .g. for
RNP, RSP, RCP, ADS -C, ADS -B, CPDLC, RVSM, etc. ) informs ATC that
your aircraft is either not equipped with or authorized to use such capabilities. The presence or absence of equipment and capability codes affects route and altitude assignments, as well as separation differences with other aircraft. You should ensure your flight plan reflects all the codes, as per flight plan guidance in the AIM, applicable to your aircraft equipment and authorizations.
6.2.2.3 The RNAV/RNP, RCP , or RSP capability indicated on your flight plan must
not be better than that for which you have been approved via an OpSpec, MSpec, or LOA, as applicable. For example, if you have only been approved RNAV/RNP 10 (code A1), you must not indicate RNP 4 capability (code L1).
6.3 Aircraft Preflight Guidance.
6.3.1 P
reflight— Necessary Documents. Effective oceanic and remote continental airspace
flight planning and execution requires a number of important pieces of information. You should ensure you have easy access to the following documents/information in the cockpit, as well as others that may be pertinent to your flight:
6.3.1.1 M
aster flight plan (“ Master Document”).
Note: Use strict procedures to manage the M aster Document. Maintain
only one OFP labeled “master” in the cockpit.
17 Regulatory reference is § 91.169 , which refers to § 91.153 . This requires the flight plan to include “any other
information the pilot in command or ATC believes is necessary for ATC pur poses.” The U.S. AIP states that pilots
must “advise ATC” if equipment failures render the filed capability indicators inaccurate.
10/4/23 AC 91 -70C
6-7 6.3.1.2 NOTAM s for departure, destination, alternate(s), ETOPS alternates
(as applicable), and applicable FIR s.
6.3.1.3 G PS NOTAMs (as applicable).
6.3.1.4 Weather for departure, destination, alternate airports along the route of flight,
and ETOPS alternates (as applicable).
6.3.1.5 SIGWX chart.
6.3.1.6 Wind charts for planned altitudes and altitudes after driftdown/emergency descent.
Note: Compute ETPs for contingencies, such as medical divert, engine
loss, rapid decompression (RD), and a simultaneous RD and engine loss. Note the location of the ETPs on your plotting/ orientation chart.
6.3.1.7 Space weather: solar flare information (see the National Oceanic and
Atmospheric Administration’s (NOAA) website at https://www.swpc.noaa.gov/forecasts ).
6.3.1.8 Volcanic ash information (as applicable).
6.3.1.9 Pilot Weather Reports (PIREP).
6.3.1.10 Receiver autonomous integrity monitoring (RAIM) and fault detection and exclusion (FDE) prediction tools (for GNSS and RNP operations), available at https://sapt.faa.gov/default.php.
6.3.1.11 Current track message (for any operations in airspace with a flexible organized track system (OTS)).
Note: If you have a track message or other separate route document
associated with the flight, verify that the effective time of the message corresponds to your flight and that the designated route agrees with
both your filed routing and the waypoint routing on your M aster
Document.
6.3.1.12 Plotting/orientation chart.
6.3.1.12.1 You should use an oceanic plotting/orientation chart, of appropriate scale, and with latitude an d longitude depicted, to provide a visual presentation of your
intended route, regardless of your type(s) of LRNS and method of cross-checking aircraft position. Plotting your route on a chart helps with situational awareness, and (together with the OFP ) also helps with navigation
contingencies such as DR , in the event of navigation system
degradation/failure.
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6-8 6.3.1.12.2 Your chart should include, at a minimum:
1. The route of your filed flight plan. If your cleared route differs from what
you filed, your currently effective route clearance .
2. Clearly depicted waypoints using standardized symbology.
3. All ETPs, plotted on the chart (with relation to the route).
4. Alternate airports.
5. Proximity of other adjacent tracks.
6.3.1.12.3 Figure 6-1 shows a sample plotting chart for an eastbound flight on a random route in the North Atlantic at FL 410. Note that the westbound tracks are plotted north of the route of flight, for situational awareness.
Figure 6 -1. Sample Plotting Chart
N
ote: For certificated operators, if you hold OpSpec/MSpec A061,
Elect ronic Flight Bag (EFB) Program, authorizing use of an EFB, the
principal inspector (PI) can authorize “interactive plotting for oceanic and remote continental navigation,” ensuring the EFB application fulfils plotting/orientation chart requirements listed in
paragraph 6.3.1.12. With this authorization, you can use your EFB
application in place of a paper plotting/orientation chart. AC 120-76,
Authorization for Use of Electronic Flight Bags, provides guidance for operators to develop associated EFB procedures. Title 14 p art 91
10/4/23 AC 91 -70C
6-9 operators may use an EFB, provided they observe the criteria and
considerations of AC 91-78, Use of Class 1 or Class 2 Electronic
Flight Bag (EFB).
6.3.2 Cockpit Preparations.
Note: These procedures assume at least two pilots are on duty. Some aircraft are
certified for single -pilot operations. If your intended flight in oceanic or remote
airspace can safely accommodate single pilot operations, you should develop some methodology to check your clearance, waypoint entries, equipment setup, etc. It may be possible to involve non- flying crew in some checks, either prior to
flight, or in -flight, via appropriate voice and/or data communications. Where such
support is not available, single pilot procedures should be carefully designed to detect and fix errors promptly, thereby minimizing or altogether preventing
deviations.
6.3.2.1 Check your maintenance log to ensure all your required communications,
navigation, and surveillance and altimetry equipm ent is operational.
1. Consult your MEL to be fully familiar with operational procedures associated with any inoperative equipment, before you depart.
2. Inoperative equipment could affect the capabilities filed in the ATC flight plan. It is important to update the codes, as needed, to ensure ATC routes you in accordance with your capabilities.
3. A departure delay to accommodate repairs may be warranted. Alternatively, a reroute to avoid oceanic airspace may be necessary.
6.3.2.2 Identify a single master clock in the cockpit.
1. Verify that your onboard primary time source, or master clock, is set to
UTC. In most cases, this time source is the FMS.
2. Use master clock times for all ETAs and actual times of arrival (ATA).
6.3.2.3 Align your inertial navigation system (INS)/inertial refere nce system (IRS).
1. Proper INS/IRS loading and operating procedures are another important aspect to help you avoid navigation errors. Ensure you select navigation (NAV) mode at the appropriate time and properly manage your navigation computer during intermed iate stops.
2. Carefully follow your inertial system flight manual procedures to ensure proper navigation reliability.
6.3.2.4 Have a second pilot independently verify the aircraft present position coordinates you have loaded in your navigation system.
10/4/23 AC 91 -70C
6-10 1. Both pilots should verify the present position in the LRNS. Aircraft
maintenance or towing can cause the present position suggested on initialization to be incorrect.
2. If you conduct another present position check on taxi out and it shows a gross difference from your gate coordinates, it could indicate a problem with the LRNS.
6.3.2.5 Two pilots should independently coordinate the loading and verification of all flight plan entries. One pilot should load the entire route into the LRNS, to include all waypoints, using the Master D ocument as source. He or she should
then verify the routing has been loaded correctly. Below are recommended steps for performing this loading and verification. The second pilot’s subsequent confirmation procedures are explained beginning in paragraph 6.3.2.6.
6.3.2.5.1 Prior to loading the flight plan, carefully cross -check the waypoint routing on
your M aster Document against your filed flight plan to verify both documents
show the same routing.
6.3.2.5.2 Ensure your navigation database and FMS software version are current and correct.
6.3.2.5.3 For systems with pilot- defined waypoint designators or numbers, we
recommend you use a consistent procedure. Enter this designator on the Master D ocument and use it to store waypoints in the navigation computer.
6.3.2.5.4 Verify all navigational information contained in the Master D ocument against
the navigation data information in the navigation system .
6.3.2.5.5 Your procedures should provide for a means of verification of the data you loaded. You should check the expanded coordinates and course/distance
between waypoints against the same information on your M aster D ocument.
You may also check the route presentati on on your navigation display. Most
long- range aircraft have a navigation system that is capable of automatically
uplinking flight plans sent from ATC or from a dispatch service. These “push
to load” flight plan uplinks are very reliable, but there are occ asional glitches
that can lead to loading partial routes, requiring you to make changes to complete the route load. Regardless of how you load your flight plan into your navigation system , you should have procedures to verify your flight plan route
against your navigation system entries.
6.3.2.6 After the first pilot has loaded and verified the navigation system entries
against the flight plan, a second pilot should recall and confirm the waypoint data against source information.
6.3.2.6.1 It is not sufficient for one crewme mber simply to observe another
crewmember entering the data. You should use an independent cross -check
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6-11 method between pilots so no navigation system entry goes unverified. An
attitude of “healthy suspicion” can facilitate good cross- checks.
6.3.2.6.2 Cross -checks sh ould include comparing the expanded coordinates of the
waypoints loaded in the navigation system to the filed flight plan, track message (if applicable), and the Master Document.
6.3.2.6.3 Verify the total route distance in your navigation system against your M aster
Document to help find embedded mistakes. A lso cross- check course/headings
and distances between each waypoint to ensure the navigation system routing matches your Master Document . Referencing your plotting or orientation
chart here can also be beneficial.
6.3.2.6.4 A 1° course deviation causes the aircraft to be off planned routing by approximately 1 mile every 60 miles of travel. A course deviation on an oceanic crossing closer to the equator, where leg lengths are typically longer, can result in cumulatively large r displacements from course. However,
although leg lengths are typically shorter at higher latitudes, and similar deviations result in cumulatively smaller displacements from course, the density of traffic and closer spacing of parallel tracks at high northern latitudes actually constitute an environment less tolerant of course deviations.
6.3.2.6.5 The second pilot should work from the navigation system back to the Master
Document (i.e., by reading what is in the navigation system , and comparing
that with what is in the Master Document ). Reading from the Master
Document to the navigation system can result in “seeing what we expect to
see” (expectation bias). A simple way to consider this is that the first pilot works from “paper to glass” while the second pilot works from “glass to paper.”
6.3.2.7 Adopt appropriate annotations to indicate the status of each waypoint listed on the Master Document . For example:
1. The first pilot could put a circle next to the waypoint, waypoint number, or
symbol on the Master Document to signify that they have independently
cross-checked the entry of the coordinates in the navigation computer.
2. The second pilot could then tick or diagonally slash the circle next to the
waypoint, waypoint number, or symbol to signify having performed the cross- check described above, to include confirming the course and
distance information within a specified toleranc e (e.g., plus or minus 2°
and 2 NM).
6.3.2.7.1 We discuss additional Master Document symbology in the en route section, in
paragraph 6.4
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6-12 6.3.2.8 Set the appropriate mode select secondary radar with data link ( Mode S) flight
identification (FLT ID), which should correspond verbatim to the Aircraft
Identification (ACID) (call sign) entered in Block 7 of the ATC flight plan.
6.3.2.8.1 ATC systems worldwide are becoming more reliant upon information transmitted by Mode S transponders to manage air traffic. ATC systems use transmitted FLT IDs to uniquely identify each aircraft within a give n airspace
and correlate them to a filed flight plan for the provision of surveillance and separation services.
6.3.2.8.2 A FLT ID is comprised of a maximum of seven alphanumeric characters (e.g., N235RA, AAL3342, BONGO33) and must agree, verbatim, with the ACID ent ered in block 7 of the ATC flight plan.
6.3.2.8.3 You typically enter your FLT ID through either an FMS interface or your transponder control panel. For ATC systems to function correctly, you must ensure the FLT ID you enter in the FMS exactly matches the ACID in bl ock 7
of the ATC flight plan.
6.3.2.9 Check your ground speed in the blocks and on taxi out.
1. If you are still in the blocks and your ground speed reads other than zero,
you may have a developing error in your LRNS.
2. Similarly, if your groundspeed on taxi out appears unreasonable, this may also indicate a problem with your LRNS.
6.3.2.10 Accomplish required RVSM altimetry ground checks.
6.3.2.10.1 Before taxi, set your altimeters to the airport local altimeter setting. Both primary altimeters should read within ± 75 feet of a known elevation (e.g., field elevation ).
6.3.2.10.2 The two primary altimeters must also agree with each other within the limits noted in the aircraft operating manual.
6.4 En Route Guidance.
6.4.1 Oceanic Clearance: How to Request, Receive, and Process.
6.4.1.1 Oceanic clearances are unique clearances that frequently require coordination between two or more air traffic agencies. The clearance you receive from an ATC facility on the ground before departure may not constitute a clearance into or through your filed oceanic and remote continental airspace. Depending on the first oceanic FIR you enter, you may need to obtain this clearance separately and specifically as you approach that airspace. Check the AIP (or
other relevant source document) to determine if such separate oceanic clearance is required.
10/4/23 AC 91 -70C
6-13 6.4.1.2 In situations where a separate oceanic clearance is required, and your
departure airport is relatively close to the oceanic airspace boundary, you may, and at some airports must, obtain your oceanic clearance prior to departure. Check the AIP or other relevant source documents to determine clearance requirements unique to your departure airport.
Note: In some airspace, ATC issues the route portion of the oceanic
clearance before the aircraft departs, even when the departure airport is not close to the oceanic boundary. In this case, ATC assigns the altitude and airspeed (as required) for oceanic crossing prior to entering oceanic airspace. New York oceanic control area ( OCA) and
Oakland OCA both operate in this manner.
6.4.1.3 In most cases, obtain your ocean ic clearance via voice at least 40 minutes
prior to entry, or 20 to 90 minutes prior if using the Aircraft Communications Addressing and Reporting System (ACARS) data link Oceanic Clearance Delivery (OCD).
6.4.1.4 CPDLC Departure Clearances provided at large U.S. airports may include an oceanic clearance. Oceanic clearances could also be issued via CPDLC from en route controllers.
6.4.1.5 When receiving a clearance via voice, at least two pilots should be involved, one actively obtaining the clearance and the other monitor ing. We recommend
both pilots be on a headset during this process.
6.4.1.6 Both pilots should independently copy the clearance. Each pilot cross- checks
and verifies the routing, altitudes, and Mach number/ airspeed assigned
(if applicable).
1. Read all waypoint coordinates back to the ATS provider in detail.
Sometimes, approved local procedures make full read back optional.
Always cross- check each detail of the clearance with your Master
Document.
2. Ensure the ATS provider acknowledges your correct read back.
3. The terms “ expect” or “when can you accept” are not used by ATC when
issuing a clearance. Typical ATC clearance phraseology is “ATC clears….”
4. After each pilot conducts an independent review and verification of the clearance, the crew should discuss the clearance to v erify a common
understanding and make any plans resulting from the clearance.
6.4.1.7 Ensure the following upon receipt of a revised clearance:
Note: A revised clearance (that is, a clearance that differs from either
the oceanic route requested via the flight plan, or f rom a previously
10/4/23 AC 91 -70C
6-14 issued oceanic clearance) is the number one scenario leading to pilot
deviation from the assigned routing. You should be particularly cautious when receiving a revised clearance.
1. A
t least two pilots should separately copy the clearance from the ATS
provider. Each pilot should be on a headset.
2. Y
ou read it back correctly and receive an acknowledgement of your read
back from the ATS provider.
3. A
ll pilots compare and analyze the clearance they just copied; contact the
ATS provider f or clarification of any inconsistencies.
4. O
ne pilot reprograms the navigation system , updates the Master
Document, and updates the plotting/orientation chart.
5. A
second pilot cross-checks the revised clearance with the reprogrammed
route loaded into the navigation system, the updated Master Document ,
and the updated plotting/orientation chart.
a. Th
e cross-check of the navigation system coordinates includes
comparing the expanded coordinates (i.e., degrees and minutes).
b. C
ourse and distance connecting the new waypoints should also be
checked. Course and distance tables are available commercially for every 10° of longitude, or dispatch may be able to send a new OFP/Master Document with the updated track and distances.
Preferably, an onboard flight planning appl ication in an EFB is used to
independently calculate course and distance, and check that against the navigation system. Legacy methods, using plotter (protractor) and pencil on a plotting chart, are also possible; pilots, however, need focused training to be proficient with these methods.
6. If th
e clearance is received via CPDLC, each pilot should read it silently to
develop an independent understanding of the new clearance, making sure the full content of the uplink has been viewed (all pages, as well as routes to be loaded). They should then discuss the clearance and ask the controller for clarification if they have any doubts as to what the clearance
means.
Not
e 1: If you receive a loadable clearance via CPDLC, the FAA
recommends you a utomatically load that clearan ce in your navigation
system. Some crews have accepted, but not automatically loaded, a CPDLC clearance to avoid losing wind data or to preserve meaningful waypoint labels. Failure to properly load the clearance in the navigation system will result in a deviation.
Not
e 2: Revised clearances sent via CPDLC have also been
associated with navigation errors. Operators should be cognizant of this when designing operating procedures for the use of CPDLC.
10/4/23 AC 91 -70C
6-15 7. Thoroughly brief all relief pilots on the revised clearance prior to them
assuming cockpit duties.
Note: We highly recommend that the relief pilot(s) also cross- check
the navigation system against the Master Document to ensure
complete understanding of the new clearance.
6.4.1.8 Ensure you have given an accurate ETA to ATC for your oceanic entry point.
If you previously provided a time estimate, and it subsequently changes in excess of 2 minutes (in the NAT , “3 minutes or greater”), you must revise
your estimate with ATC.
Note: Pilots do not need to provide a revised estimate when under
ATS s urveillance ( refer to ICAO Doc 4444, Procedures for Air
Navigation Services —Air Traffic Management, paragraph 8.6.4.4).
Also, for aircraft providing automatic position reports via ADS- C,
position reports can be omitted “in airspace where ADS -C services are
provided” ( refer to ICAO Annex 2, paragraph 3.6.2.2). Nonetheless,
domestic controllers often relay the pilot- provided estimate to oceanic
controllers, and separation can be predicated on that time estimate.
6.4.1.9 Yo u must also ensure you enter oceanic airspace at your cleared/assigned FL
for the crossing. The domestic ATC sector does not always automatically clear you to the oceanic clearance altitude; if this appears to be happening, query ATC.
6.4.2 Communications/Navigation/Surveillance System Checks.
6.4.2.1 You should have checked your HF radios prior to departure. If you were unable to get a good check on the ground, check them prior to entering oceanic and remote continental airspace.
6.4.2.2 Accomplish a SELCAL check prior to oceanic and remote continental airspace entry and then again at each CTA boundary. Check your SELCAL even when your CPDLC is working properly.
6.4.2.3 If you are using SATVOICE to communicate with ATC via New York or San Francisco Radio, the FAA requires a SATVOICE Callback Check, with a sample transcript provided in paragraph 4.3.3.2. You can find operational
policy regarding the use of SATVOICE in the U.S. AIP , section ENR 7. You
may find changes to SATVOICE policy, between AIP publica tion cycles,
posted on the FAA’s International Notices website.
6.4.2.4 For certificated operators, your OpSpecs or MSpecs will prescribe the requirements for confirming your navigation accuracy, and assessing the performance of your LRNS, prior to entering oceanic airspace. We recommend GA operators perform similar navigation accuracy checks, as
10/4/23 AC 91 -70C
6-16 further described in paragraph D.2.5.1 of the sample oceanic checklist
provided in Appendix D.
6.4.2.5 Upon entering oceanic and remote continental airspace, verify that the RNP
alerting by your FMC is consistent with the RNP capability indicated on your flight plan. If you indicate RNP 4 capability on the flight plan, for example, FMC alerting must be no higher than 4.0.
6.4.2.6 If you are no longer able to meet your RNP navigation specification (NavSpec) while en route (i.e., your Actual Navigation Performance (ANP)
exceeds your RNP or required equipment has failed, or you rece ive an
“UNABLE RNP” alert), you are required to immediately notify your ATS provider so they can adjust separation standards between you and other nearby aircraft as required.
6.4.2.7 If you plan to use SATCOM data link systems, check them prior to oceanic airspace entry. AC 90-117, Data Link Communications, recommends you
initiate logon /notification for CPDLC and/or ADS-C services 10 to
25 minutes prior to the oceanic/FIR boundary, unless otherwise specified in the relevant AIP.
6.4.2.8 C
onduct altimetry checks prior to entering oceanic airspace and every hour
thereafter, or as specified in the aircraft flight ma nual. Your two primary
altimeters should read within 200 feet of each other.
Note: We recommend you record these readings, along with their
times, on your Master Document . This will aid you in determining the
most accurate altimeter in the event of a subsequent altimetry problem.
6.4.3 E ntering Oceanic and Remote Continental Airspace—First Steps .
6.4.3.1 Set your transponder in accordance with regional requirements (generally to
code 2000). This requirement varies with the oceanic airspace. You should
confirm these procedures, through applicable AIP or other regional documents
during flight planning. In the NAT, for example, pilots should change the transponder code 30 minutes after entering oceanic airspace. In the Pacific, Oakland advises that pilots should change the transpo nder code “upon
entering” the OCA, after radar (/surveillance) services are terminated.
6.4.3.2 Adjust your airspeed to maintain your assigned Mach number, as applicable.
6.4.3.3 Once you have departed VHF radio range, set your radios to air- to-air
(generally 123.45) and guard (121.5) frequencies.
6.4.3.3.1 ATC and air defense authorities will generally attempt contact with aircraft on guard (121.5 or 243.0 MHz) before ordering an intercept. For this reason, all aircraft are highly encouraged to maintain a listening watch on guard.
10/4/23 AC 91 -70C
6-17 6.4.3.3.2 The AIM, chapter 5, s ection 6, addresses interception procedures and provides
the intercepting signals table published in ICAO Annex 2.
6.4.3.3.3 The International Air Transport Association (IATA) has developed widely
adopted procedures for use in FIRs where poor communications and/or reduced quality of ATS may pose a flight hazard. See Appendix E
, IATA
In-Flight Broadcast Procedure, for IATA procedures for transponder use and
radio broadca st in affected areas. The procedures involve maintaining a
listening watch and broadcasting aircraft position “in the blind.”
6.4.3.4 Institute an appropriate offset, based on the SLOP, unless not authorized. Use
of SLOP helps mitigate the heightened risk of colli sion due to highly accurate
navigation systems, and it helps avoid wake turbulence.
6.4.3.4.1 SLOP guidance is published in the U.S. AIP, Part 2, En Route (ENR), and ICAO Doc 4444, section 16.5. As a reminder, SLOP offsets are only right of
course.
6.4.3.4.2 We recommend SLOP be part of your oceanic training program and standard procedures for oceanic flying. You should check applicable State AIPs to determine where use of SLOP is authorized.
6.4.3.5 Specify which FMS pages, or other displays of navigation information, that individual flightcrew members are charged with monitoring during the oceanic portion of the flight (e.g., cross- track error or time/distance).
6.4.4 The Master Document: A Suggested Method for Managing It.
6.4.4.1 A Master Document is a cop y of the OFP (also referred to as navigation log,
or computer flight plan (CFP) ) with “MASTER” written on it. It does not
“belong” to the pilot or the copilot, but rather is the flightcrew’s central reference document to record clearances, frequencies, ETA s notified to ATC,
fuel status, and other operational information. The Master Document is also used to record verification of waypoint information, and should be kept current and organized so pilots can easily understand the progress of the flight, to include the currently effective route clearance. ICAO NAT Doc 007
provides further details on recommended use of a Master Document , and
notes that it should list sequentially the waypoints defining the route, the course and distance between each waypoint, and other information relevant to
navigation along the cleared route.
6.4.4.2 Suggested Master Document annotations are provided here to help operators standardize procedures. Other annotations, for example, squares, rectangles,
or hash marks, could be used as well, a s long as they are part of a clearly
defined and standardized process of managing the Master Document.
10/4/23 AC 91 -70C
6-18 6.4.4.2.1 A circle next to the waypoint identifier denotes both pilots verified the
coordinates, courses , and distances. This would normally be done during
initial navigation system loading.
A diagonal backslash ( \) over the circle denotes confirming a subsequent
waypoint’s coordinates and the track and distance to it. An ETA for that
waypoint is also recorded. This would normally be done after rollout on the
new course, and/or approaching the active waypoint.
As you make your position report over the waypoint, note your fuel remaining on the Master Document next to that waypoint. This is especially important if
the cleared route and FL differ from your flight plan.
Approaching each oceanic waypoint, verify the next and subsequent
(“next + 1”) waypoints. Using your currently effective route clearance:
1. Check the expanded FMC coordinates for the next and subsequent
waypoints, and
2. Check that the expected outbound magnetic course and distance to t he
next waypoint presented in the FMC agree with that clearance.
6.4.4.2.4 A diagonal forward slash (/) turns the previously annotated back- slash into an
“X.” This denotes waypoint passage. Overhead time is confirmed with a
“check” (or updated time, as applicable) and f uel remaining is annotated.
10/4/23 AC 91 -70C
6-19 As you pass each waypoint, verify the aircraft is progressing on the correct
route by cross- checking the leg distance and magnetic course on the Master
Document against the distance and magnetic course to the next point as displayed on the avionics.
6.4.5 Position Reporting—General Requirements.
6.4.5.1 Communications over HF radio rely heavily on proper radio terminology and scripted reports. Use the published guidance found in en route publications or the AIM to make sure you deliver messages in the proper format.
1. You are expected to speak at a moderate speed using internationally accepted phraseology.
2. Be certain you are communicating with the facility appropriate to the oceanic and remote continental airspace in which you are operating or about to enter. More than one station may be using the same HF frequency at the same time. Only accept clearances from the ATS provider for the oceanic and remote continental airspace in whi ch you are operating.
6.4.5.1.1 Radio c all signs of ground stations. Position reports are generally provided to
aeronautical radio stations, which relay this information to ATC. If the ATS provider you are talking to is identified as a “Center,” (e.g., “Gander Cente r”)
or a “Control” (e.g., “Tokyo Control”), you are talking directly to an air traffic controller. If the provider you are talking to is id entified as a “Radio”
(e.g., “New York Radio”), you are talking to an aeronautical radio station, which is a relay fa cility that communicates between the ATC controlling
facility and aircraft. An aeronautical radio station does not control air traffic —
it relays the instructions of the ATC facility.
6.4.5.1.2 You must report departing your current FL. In certain regions, the NAT for
example, you are also required to report reaching your assigned altitude. You
should consult the appropriate regional or State documents (e.g., ICAO NAT Doc 007, AIP, Chart Supplement, etc.) to confirm reporting requirements.
6.4.5.1.3 In addition to reporting your position to your current ATS provider, in the case of boundary points, often you must repeat your last position report to the FIR or CTA you are entering. Do so when so prescribed in the appropriate section of ICAO Doc 7030
, Regional Supplementary Procedures, in the
applicable AIP, or when requested by ATC.
6.4.5.1.4 If another aircraft relays your report, use the appropriate air- to-air frequency
and not the emergency (guard) frequency.
6.4.5.1.5 If you operate in airspace approved for the use of data link, you may provide automatic position reporting via ADS -C. In this case, you should discontinue
voice position reports.
10/4/23 AC 91 -70C
6-20 6.4.5.2 When following a designated oceanic route, you must make position reports
when passi ng each designated compulsory reporting point.
Note: The appropriate ATS authority may request reports over
non-compulsory reporting points as well. In oceanic airspace where the FAA is the ATS provider, position reports are required over all points used in the flight plan to define the route of flight, even if they
are non-compulsory.
6.4.5.3 If you are not on a designated oceanic route, provide position reports at all points listed in Item 15 (route of flight) of the flight plan. ATC expects reports as soon as possible after the first half hour of flight in oceanic and remote continental airspace and at hourly intervals thereafter. The appropriate ATS provider, however, may request additional reports at shorter intervals of time.
1. If your flight tracks predominantly east and west, ATS providers will
generally request reports every 5° or 10° of longitude.
2. If your flight tracks predominantly north and south, ATS providers will generally request reports every 5° or 10° of latitude.
6.4.6 P
osition Reporting—Format.
6.4.6.1 See the AIM, chapter 5, for general guidance on position report format. You
must provide information regarding your current fix and the next two fixes on your route of flight, in the following order:
1. Your complete aircraft call sign.
2. Your position and crossing time, reported in 4 digits UTC.
Note: In reporting coordinates and times, say each number
individually (e.g., 1032 is “one zero three two,” not “ten thirty-two”).
You do not have to say “UTC” or “Zulu” when you report the time.
3. Your FL.
4. Your next fix and estimate over that fix in 4 digits UTC.
Note: If any reported ETA changes in excess of 2 minutes (3 minutes
or more in the NAT), you must provide an updated estimate to the
ATS provider.
5. Name of your subsequent fix.
6.4.6.2 An example position report is:
“N1234 over CEBEN at 1422, FL350, estimating CIVIT 1503, CORTT next.”
6.4.6.3 When position is expressed in coordinates, the following pertains:
10/4/23 AC 91 -70C
6-21 1. If your flight tracks predominantly east and west, ATS providers will
generally expect latitude to be expressed in degrees and minutes, and longitude in whole degrees only.
2. If your flight tracks predominantly north and south, ATS providers will generally expect latitude to be expressed in whole degrees only, and longitude in degrees and minutes.
6.4.6.4 A 2010 change to ICAO Annex 3 cancelled the requirement to report wind
and temperature data via voice. You should continue to report any turbulence or other significant meteorological conditions you encounter to AT C.
Note 1: E
nsure the reporting of such meteorological observations references your geographical coordinates at the time of occurrence.
Note 2: ICAO NAT Doc 007 has a form for reporting significant
wake turbulence encounters. We encourage you to submit this form whenever you encounter significant wake turbulence while operating in NAT airspace, in order to support the monitoring efforts of the NAT airspace authorities.
6.4.7 N
avigation Cross -Checking Procedures: Why They Are Important.
6.4.7.1 ICAO Doc 7030 includes language requiring t he State of Registry or the State
of the Operator to approve operator programs established to mitigate the occurrence of navigational errors due to equipment malfunction or operational error. These operator programs must include in -flight operating drills,
consisting of mandatory navigation cross-checking procedures, to identify navigation errors in sufficient time to prevent aircraft from inadvertent deviation from an ATC- cleared route.
6.4.7.2 Navigation cross -check procedures mitigate risk and promote situational
awareness— an essential requirement for crews operating highly automated
airplanes in increasingly crowded airspace. Such procedures help ensure aircraft operating under procedural ATC control are in fact maintaining the separation from other aircraft tha t ATC has planned and is expecting.
Cross -check procedures enable pilots to be certain they are where they think
they are; this awareness becomes particularly critical during emergency situations.
6.4.7.3 While advances in navigation accuracy and communications capability generally enhance safety and reduce flightcrew and controller workloads, these advancements have not eliminated human errors. Pilot deviations continue to occur and can be attributed to complacency, poor operational procedures, poor understanding of systems and processes, or simply human
frailties such as cognitive or auditory failures.
10/4/23 AC 91 -70C
6-22 Note: Numerous deviations in oceanic airspace are the result of
flightcrews failing to follow revised clearances. Transposed numbers,
misunderstood clearances, or route amendments not properly verified or not passed on to relief crewmembers also contribute to navigation errors. In addition, paragraph 4.4.3 describes issues with displays of
CPDLC messages; Figure 4-1 shows sample FMS pages flightcrews
would interact with to load an uplinked, revised route.
6.4.8 Navigation Cross - Checking—Acceptable Procedures.
6.4.8.1 In line with the rationale and requirements for navigation cross -checking
procedures described in paragraph 6.4.7, the FAA believes cross- ch ecking is
synonymous with “making sure.” We consider the “sample oceanic checklists,” provided in Appendix D , to provide operators with not only a
“to-do” list but also a means to make sure certain items, known to result in
navigation errors if overlooked or done incorrectly, are pe rformed in a n
organized, systematic manner.
6.4.8.2 T he sample checklists (simple and expanded versions) provided in
Appendix D are derived from ICAO NAT OPS Bulletin 2017 -005, Sample
Oceanic Checklists. In these checklists, we have provided two acceptable methods for cross -checking aircraft posit ion at a point approximately
10 minutes after oceanic waypoint passage. Previously, the only recommended method of cross-checking aircraft position in the oceanic airspace environment was manual plotting on a chart. However, a panel of aviation industry and FAA personnel completed an Operational Safety Assessment (OSA) of methods for cross-checking oceanic flight navigation. The panel determined that an alternative to manual plotting, by which aircraft
position could be checked through use of aircraft FMS-driven navigation
displays and indications, would provide for an equivalent level of safety. See Appendix D, paragraph D.2.9.2.
6.4.8.3 The check of aircraft position at a point approximately 10 minutes following waypoint passage is designed to enable you to observe and correct a navigation error before safety of flight is jeopardized. If you made a subtle mistake either while en route to or crossing a waypoint, 10 minutes of travel should allow you to observe that mistake before significant problems result. These cross -checks are a backup to an otherwise well -planned flight that is
being executed through systematic and disciplined attention to effective procedures, such as those provided in this chapter and Appendix D. The cross- checks are not designed to overcome poor planning, sloppy procedures
or inadequate attention to detail. To reiterate: in -flight operating drills, to
include cross -checking of navigation during oceanic and remote continental
airspace operations, are mandatory under ICAO standards.
10/4/23 AC 91 -70C
6-23 Note 1: Some operators use 2 degrees of travel instead of 10 minutes.
This would generally also be approximately 10 minutes, depending on
a number of factors.
Note 2: If your method and technique of position cross- checking
allow observation of an error earlier, i t is acceptable to do the check at
approximately 5 minutes after waypoint passage, or 1 degree of travel.
6.4.8.4 The FAA recognizes that, for any number of reasons, operators may require or choose to use navigation cross-checking procedures different from those i n the
oceanic checklist provided in Appendix D. For those operators who require operational approval, whether to operate in oceanic and remote continental airspace in general, to operate in airspace where RNP is prescribed, or to operate within oceanic and remote SAO s, such as NAT HLA, their choice of
procedures will help establish the basis of that approval. Operational approval will be predicat ed upon use of either the cross-checking procedures described
in the sample oceanic checklist (Appendix D ) or via an alternative method that
will achieve an equivalent level of safety. In order to determine equivalent levels of flight safety, an operator’s proposed alternative cross -checki ng
procedures will be assessed, by the PI and a specialist from the FAA’s Flight Technologies and Procedures Division, Flight Operations Group , against the
following criteria:
1. A
re they written, standardized, and required for use by the operator’s
flightcre ws?
2. Do they require use of a plotting or orientation chart, of adequate scale, for reference/situational awareness purposes?
3. Do they address all the major functions/action points (e.g., independent
route verification; at waypoint passage; after waypoint passage) outlined
in the sample oceanic checklist?
4. Do they provide for confirming that the aircraft is flying toward, via the expected course/track line, the intended/expected waypoint contained in the flight’s currently effective route clearance ?
5. Do they prescribe periodic cross -checking, for reasonableness, of the
position data reported by all onboard navigation systems?
6. Do they require checking of aircraft position approximately 10 minutes after each oceanic waypoint prescribed in the currently effective route clearance ?
7. Do they direct prompt and proper correction for any detected deviations from the currently effective route clearance?
8. Do they establish acceptable tolerances for track deviation, as well as course/heading/distance between waypoints, when compared between the flight plan and the navigation system?
10/4/23 AC 91 -70C
6-24 9. Do they include ready reference to, and direct compliance with, accepted
in-flight contingency procedures (refer to ICAO Doc 4444)?
Note: Alternative methods proposed by certificated operators will also require
review/approval by the Flight Standards Service (FS) .
6.4.8.5 If an operator adopts new oceanic procedures, it is crucial this be done as part of a carefully orchestrated effort in close coordination with both your PI and a specialist from the Fl ight Operations Group. Checklists need to be tailored to
reflect operator- unique aspects, manuals need to be updated, and crews need
to be trained. Failure to properly implement the change can lead to confusion, misunderstandings, and errors.
6.4.8.6 Diligent cros s-checking of the navigation system and Master Document
against the currently effective route clearance remains the key to preventing inadvertent deviations from the cleared route.
1. The active leg is the most immediate indication of adherence to the
currently effective route clearance. The active leg is formed by a “FROM”
position and a “TO” waypoint, and features an associated course to fly between the points; this information should be cross- checked against the
OFP.
2. In addition to verifying the “TO” waypoi nt, the FAA also recommends the
flightcrew verify autopilot steering mode (e.g., lateral navigation
(LNAV)/NAV, not Heading (HDG)).
3. When checking waypoints, ensure you look at the “expanded” (i.e., degrees and minutes) coordinates. Some waypoint labels can be misleading.
6.4.8.7 While the procedures discussed above, and the items provided in the oceanic
checklists in Appendix D, emphasize prevention of lateral errors, we want to
emphasize that altitude deviations and longitudinal errors are no less
significant. Steps to avoid those two types of errors in oceanic operations are discussed further in paragraph 6.1.2.
6.4.9 Relief Pilots —Preparing to Assume Duties . Increasingly, with long-range operations,
relief pilots are part of the crew. In such cases, it is vital to brief the relief pilot on all current operational issues affecting the flight.
1. M
any navigation errors have been traced back to inadequate handoff between pilots
who first loaded the route into the navigation system and relief pilots who took over hours into the flight. It is therefore vital that you fully brief the relief pilot on your
currently effective route clearance.
2. We recommend the relief pilot verify the current cleared route prior to occupying the seat, if practical. Work from the navigation system to the Master Document to lessen
10/4/23 AC 91 -70C
6-25 the risk of expectation bias (seeing what is expected) and maintain an attitude of
“healthy suspicion.”
6.4.10 Exiting Oceanic and Remote Continental Airspace . Refer to the Coast -In step in the
Sample Oceanic Checklist (Appendix D).
10/4/23 AC 91 -70C
7-1 CHAPTER 7. IN-FLIGHT CONTINGENCY G UIDANCE FOR OPERATIONS IN
OCEANIC AIRSPACE
7.1 Contingency Procedures: When They May Be Needed. ICAO Doc 4444 includes
contingency procedures to allow you to safely deviate from your assigned clearance, in
the event a revised clearance cannot first be obtained. The procedures are designed to rapidly separate you from the regular flow of traffic while you address an emergency. Although we can’t cover all possible emergencies you may face, the more common cases that might drive you to fly oceanic contingency procedures include:
1. U
nexpected meteorological conditions, e.g., severe weather and/or turbulence.
2. Degradation s in aircraft performance.
• Aircraft engine or pressurization failure.
• Inability to maintain cleared FL (e.g., due to unexpected temperatures).
• Loss of, or significant reduction in, navigation capability.
3. Loss of communications capability. This can have many causes:
• Degradation or failure of aircraft communication equipment.
• Degradation or failure of ground communication equipment.
• Unexpected closure of an oceanic ATC facility.
4. Medical situations.
7.1.1 A dhering to Contingency Procedures. Keep in mind that you mus t follow these
contingency procedures precisely as written. If you fail to do so, you incur additional risk
by invalidating procedures designed to prevent collisions. To be clear, for operations in airspace where direct controller -pilot VHF voice communica tions are not available, the
only assurances of safe separation come when all aircraft are flying the exact track and altitude assigned by ATC. ATC can no longer assure safe separation when an aircraft deviates from the assigned track or altitude, without prior clearance. The contingency procedures, if followed exactly, minimize the risk inherent in these deviations.
7.2 C
hoosing the Correct Contingency Procedure.
7.2.1 P rimary Guidance . ICAO Do c 4444, section 15.2, contains primary guidance for oceanic
contingency procedures. ICAO Doc 7030 includes additional, region- sp ecific guidance,
generally in chapter 9 of each regional section. The procedures are also described in the En Route (ENR) 7.3 section of the U.S. AIP . Refer also to the FAA’s International
Notices website, which will include any changes or regional applications to contingency
procedures.
Note 1: O n November 5, 2020, ICAO changed oceanic contingency procedures
globally, to use 5 NM offsets for the general procedures, and an altitude deviation beginning at 5 NM for the weather contingency procedures.
10/4/23 AC 91 -70C
7-2 Note 2: Whenever possible, obtain a revised clearance instead of flying a
contingency procedure. If the nature of the emergency precludes this, consider
querying ATC about safest routes, even if ATC is unable to clear you that way.
7.2.2 G eneral and Weather Deviation Contingency Procedures. A “General” contingency
procedure is available, as is a weather deviation procedure. Flightcrews should be thoroughly familiar with these procedures and ensure ready access to them on the flight
deck so they may be performed precisely and without undue delay.
7.2.2.1 T
he general procedure results in a 5 NM lateral offset, at an altitude of 500 or
1,000 feet “different from those normally used.” It is reprinted in Appendix F ,
Special Procedures for In -Flight Contingencies in Oceanic Airspace.
7.2.2.2 T he weather deviation procedure results in an altitude change of 300 feet,
when the lateral dev iation reaches 5 NM from centerline. It is also reprinted in
Appendix F.
7.3 Altimetry and/or Navigation Degradation. You must notify the ATS provider as soon
as possible if your altimetry and/or navigation systems have degraded below that required
to operate in RVSM, RNP, or RNAV airspace. In general, that notification, either via voice or CPDLC, will include the phrase “UNABLE RNP (OR RNAV OR RVSM) DUE EQUIPMENT.”
7.3.1 Whenever possible, you should request a revised clearance that accounts for the
degradation you have experienced . Upon receipt of your message, ATS providers will
assess the traffic situation and either allow you to remain as filed or issue a reroute, depending on your current (and projected future) separation from other traffic.
7.3.2 For navigation degradation scenarios, dead reckoning procedures may be required. Flightcrews should be familiar with determining heading and leg time required, through the use of the Master Document, the chart, and/or EFB applications.
Note: ICAO NAT Doc 007 provides specific procedures to be used in the NAT in
the event of navigation system degradation or failure.
7.4 L ost Communications Procedures. The general rules for lost co mmunications are
captured in ICAO Annex 2, chapter 3, and are included in their entirety in ICAO
Doc 4444, section 15.3.
7.4.1 Region- S pecific Rules. In some regions, ATS authorities have am ended the rules to meet
their specific air traffic management (ATM ) requirements. These amended rules are
included in ICAO Doc 7030, generally in c hapter 9 of the applicable region’s section.
ICAO NAT Doc 007 also provides a detailed discussion of lost communications
procedures specific to NAT airspace. Refer also to the FAA’s International Notices
website, which will include any changes or regional applications to lost communications
procedures.
10/4/23 AC 91 -70C
7-3 7.4.2 Preflight Preparation. Prior to departure, ensure you are familiar with the lost
communications rules for the regions you are transiting. The guidance in the following
paragraphs is not all-inclusive and should not be the sole basis for your understanding of the lost communications rules that impact your trip.
7.4.2.1 ATS authorities expect you to maintain your last assigned speed and altitude for some period (usually 20 minutes or 60 minutes, depending on the region), then adjust your speed and altitude to conform to your flight plan.
7.4.2.2 In the NAT region:
7.4.2.2.1 If you have received an oceanic clearance, you are expected to proceed to your oceanic entry point and enter at your cleared oceanic FL and airspeed, then fly your ATC-cleared routing, FL, and airspeed through oceanic airspace, picking up your filed flight plan route upon oceanic exit, even if your oceanic clearance differed from your flight planned oceanic routing.
7.4.2.2.2 If you have not yet received an oceanic clearance, you a re expected to proceed
to your filed oceanic entry point and fly your filed oceanic routing, FL, and airspeed, then continue along your filed route upon exiting oceanic airspace.
7.4.2.3 You can find specific direction in ICAO Doc 4444 and ICAO Doc 7030. This direction is not the same for every region, so make sure you understand the
procedure for the region(s) through which you intend to operate, as well as those for the national airspace structure you will enter upon exiting oceanic airspace.
7.4.3 Unexpected Closure of an Oceanic ATC Facility . See Appendix F , paragraph F.4
for
considerations in the event of an oceanic ATC facility shutdown.
7.5 Normal Aircraft Tracking. ICAO, in Annex 6 , Part I, paragraph 3.5 established a
requirement for an automated 4D (latitude, longitude, altitud e, and time) tracking
capability for oceanic operations involving aircraft above a certain weight and seating capacity. The FAA recommends all operators establish some automated capability to track the position of their aircraft during oceanic operations using a means that does not require direct flightcrew action. ICAO Circular 347, Aircraft Tracking Implementation Guidelines, provides additional information.
10/4/23 AC 91 -70C
Appendix A
A-1 APPENDIX A. ABBREVIATIONS AND DEFINITIONS
A.1 Abbreviations.
Acronym Description
14 CFR Title 14 of the Code of Federal Regulations
AC Advisory Circular
ACARS Aircraft Communications Addressing and Reporting System
ACAS Airborne C ollision Avoidance Syst em (same as TCAS)
ACID Aircraft Identification
ADIZ Air Defense Identification Zone
ADS Auto matic Dependent Surveillance ( in older documents published before
ADS -B existed, “ADS ” generally refers to ADS -C)
ADS -B Auto matic Dependent Surveillance -Broadcast
ADS -C Automatic Dependent Surveillance -Contract
AFI African -Indian Ocean Region ( per ICAO)
AIM Aeronautical Infor mation Manual
AIP Aeronautical Infor mation Publication
AMU Area of Magnetic Unreliability
AMVER Automated Mutual -assistance Vessel Rescue
ANP Actual Navigation Performance
ARTCC Air Route Traffic Control Center
ATA Actual Ti me of Arrival
ATC Air Traffic Control
ATM Air Traffic Manage ment
ATOP Advanced Technologies and Oceanic Procedures
ATS Air Traffic Service
ATSP Air Traffic Service Provider
CAA Civil Aviation Authority
CEP Central East Pacific
CFP Computer Flight Plan
CMNPS Canadian Minimum Navigation Performance Specifications
CPDLC Controller -Pilot Data Link Communications
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Appendix A
A-2 Acronym Description
CTA Control Area
DOS Department of State
DR Dead Reckoning
EDTO Extended Diversion Time Operations
EFB Electronic Flight Bag
ETA Estimated Time of Arrival
ETOPS Extended Operations
ETP Equal Time Point
EWINS Enhanced Weather Information Systems
FAA Federal Aviation Administration
FANS 1/A Future Air Navigation System 1/A (1=Boeing; A=Airbus)
FDE Fault Detection and Exclusion
FIR Flight Information Region
FL Flight Level
FLT ID Flight Identification
FMC Flight Management Computer
FMS Flight Management System
FRMS Fatigue Risk Management System
GA General Aviation
GNE Gross Navigation Error
GNSS Global Navigation Satellite System
GOLD Global Operational Data Link Document
GPS Global Positioning System
HF High Frequency
HLA High Level Airspace
hPa Hectopascal
IAP Instrument Approach Procedure
IATA International Air Transport Association
ICAO International Civil Aviation Organization
IFBP In-Flight Broadcast Procedure
IFR Instrument Flight Rules
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Appendix A
A-3 Acronym Description
IMC Instrument Meteorological Conditions
INS Inertial Navigation System
IRS Inertial Reference System
LHD Large Height Deviation
LNAV Lateral Na vigation
LOA Letter of Authorization
LRC Long Range Cruise
LRCS Long -Range Communication System
LRNS Long -Range Navigation System
MEL Minimum Equipment List
MHz Megahertz
MMEL Master Minimum Equipment List
Mode S Mode Select Secondary Radar With Data Link
MSpecs Management Specifications
NAS National Airspace System
NAT North Atlantic
NAT HLA North Atlantic High Level Airspace
NATO North Atlantic Treaty Organization
NAV Navigation
NAVAID Navigational Aid
NavSpec Navigation Specification
NM Nautical Miles
NOPAC North Pacific
NOTAM Notice to Air Missions
NWS National Weather Service
OAPS Operations Approval Portal System
OCA Oceanic Control Area
OESB Oceanic Error Safety Bulletin
OFP Operational Flight Plan
OpSpecs Operations Specifications
OTS Organized Track System
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Appendix A
A-4 Acronym Description
PBC Performance -based Communication
PBCS Performance -based Communication and Surveillance
PBN Performance -based Navigation
PI Principal Inspector
PIC Pilot in Command
PIREP Pilot Weather Report
POI Principal Operations Inspector
PPO Prior Permission Only
QFE Atmospheric pressure at aerodrome elevation (or at runway threshold) .
(With the runway threshold QFE set in the subscale, your altimeter will
read zero on the runway thresho ld.)
QNE Pressure Altitude (Flight Level) , obtained with Standard Pressure
(29.92 in Hg or 1013.2 hPa) set in the altimeter subscale.
QNH The pressure set on the subscale of the altimeter so that the instrument
indicates its height above sea level.
RA Resolution Advisory
RAIM Receiver Autonomous Integrity Monitoring
RCP Required Communication Performance
RD Rapid Decompression
RNAV Area Navigation
RNP Required Navigation Performance
RSP Required Surveillance Performance
RVSM Reduced Vertical Separation Minimum
SAO Special Area(s) of Operation
SAR Search and Rescue
SARP s Standards and Recommended Practices (ICAO)
SATCOM Satellite Communications
SATVOICE Satellite Voice
SELCAL Selective Calling System
SIGWX Significant Weather
SLOP Strategic Lateral Offset Procedure s
SMS Safety Management System
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Appendix A
A-5 Acronym Description
SOP Standard Operating Procedure
SSR Secondary Surveillance Radar
SUA Special Use Airspace
SUPPS Regional Supplementary Procedures (ICAO Doc 7030 )
SWPC Space Weather Prediction Center
TAF Terminal Aerodrome Forecast
TCAS Traffic Alert and Collision Avoidance System
TIBA Traffic Information Broadcasts by Aircraft
TSO Technical Standard Order
UTC Coordinated Universal Time
VAAC Volcanic Ash Advisory Center
VFR Visual Flight Rules
VHF Very High Frequency
WebOPSS Web -based Operations Safety System
WGS 84 World Geodetic System 1984
A.2 Definitions.
A.2.1 Advisory Airspace. Airspace of defined dimensions, or a designated route, within which
air traffic advisory service is available.
A.2.2 Aeronautical Information Manual (AIM) . A primary FAA publication whose purpose is
to provide the aviation community with basic flight information and ATC procedures for
use in the NAS of the United States. The AIM contains items of interest to pilots
concerning health and medical facts, factors affecting flight safety, a pilot/controller
glossary of terms used in the ATC System, and information on safety and accident and
hazard reporting.
A.2.3 A eronautical Information Publication (AIP) (ICAO). A publication issued by or with the
authority of a State and containing aeronautical information of a lasting character
essential to air navigation.
A.2.4 A eronautical Telecommunication Station . An aeronautical station which forms part of a
radio telephone network by providing air/ground communications and flight information service as an integral part of ATS. Aeronautical telecommunication stations are also known as international Flight Service Stations (FSS), Aeronautical Radio, or Aeradio Stations, depending on the State providing the service.
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Appendix A
A-6 A.2.5 Airborne Collision Avoidance System (ACAS) (ICAO). An aircraft system based on SSR
transponder signals, which operates independently of ground-based equipment to provide
advice to the pilot on potential conflicting aircraft that are equipped with SSR
transponders.
A
.2.6 Air Defense Identification Zone (ADIZ). Airspace over land or water, extending upward
from the surface, within which the ready identification, location, and control of aircraft are required in the interest of national security.
A.2.7 Air Traffic Advisory Service (ICAO). A service provided within advisory airspace to
ensure separation, in so far as practical, between aircraft that are operating on IFR flight plans.
A.2.8 Air Tra
ffic Management (ATM) (ICAO). The dynamic, int egrated management of air
traffic and airspace including ATS, airspace management, and air traffic flow management—safely, economically, and efficiently—through the provision of facilities and seamless services in collaboration with all parties an d involving airborne and
ground-based functions.
A.2.9 Air Traffic Management (ATM) System (ICAO). A system that provides ATM through
the collaborative integration of humans, information, technology, facilities, and services, supported by air and ground- and/or space -based communications, navigation, and
surveillance.
A.2.10 Air Traffic Service (ATS) (ICAO). A generic term meaning variously flight information
service, alerting service, air traffic advisory service, ATC service, area control service, or approach control service.
A.2.11 Air Traffic Service (ATS) Surveillance System (ICAO). A generic term meaning
variously, ADS- B, Primary Surveillance Radar (PSR) , SSR, or any comparable
ground- based system that enables the identification o f aircraft. A comparable
ground- based system is one that has been demonstrated, by comparative assessment or
other methodology, to have a level of safety and performance equal to or better than monopulse SSR.
A.2.12 Alerting Service (ICAO). A service provided to notify appropriate organizations
regarding aircraft in need of SAR aid and to assist such organizations as required.
A.2.13 Area Control Center (ACC) (ICAO). A unit established to provide ATC service to
controlled flights in CTAs under its jurisdiction. ACCs are the international equivalent of U.S. ARTCC.
A.2.14 Area of
Magnetic Unreliability (AMU). As aircraft move towards the Earth’s north or
south magnetic pole, the horizontal field strength diminishes and the ability of the compass to accurately sense magnetic north is reduced. It is generally recognized that when the horizontal magnetic field strength falls below 6000 nanotesla, the magnetic compass can no longer be considered to be reliable.
10/4/23 AC 91 -70C
Appendix A
A-7 A.2.15 Area Navigation (RNAV) (ICAO) . A method of navigation that permits aircraft operation
on any desired flight path within the coverage of ground- or space- based NAVAIDS or
within the limits of the capability of self -contained systems or a combination of these.
A
.2.16 Automatic Dependent Surveillance (ADS) . A surveillance technique in which aircraft
automatically provide, via a data link, data derived from onboard navigation and position
fixing systems, including ACID, four-dimensional position, and additional data as appropriate.
A.2.16.1 A
utomatic Dependent Surveillance -Broadcast (ADS -B) (ICAO). A
surveillance system by which aircraft, aerodrome vehicles, and other objects
can automatically transmit and/or receive data such as identification, position, and additional data, as appropriate, in a broadcast mode via a data link.
A.2.16.2 Automatic Dependent Surveillance -Contract (ADS -C) (ICAO). A means
by which the terms of an ADS -C agreement will be exchanged between the
ground system and the aircraft, via a data link, specifying under what conditions ADS -C reports would be initiated and what data would be
contained in the reports. The abbreviated term “ADS contract” is commonly used to refer to ADS event contract, ADS demand contract, ADS periodic contract, or an emergency mode.
A.2.17 C
onditional Clearances . A conditional clearance is an ATC clearance given to an aircraft
with certain conditions or restrictions, such as changing an FL based on a UTC time or a specific geographic position. In oceanic and remote continental airspace, this usually involves a restriction to comply with the clearance “BY” or “AT” a certain geographic position or time.
A.2.18 Control Area (CTA) (ICAO) . A
controlled airspace extending upwards from a specified
limit above the Earth.
A.2.19 Controller- P ilot Data Link Communications (CPDLC). A two -way digital
communications system that conveys textual ATC messages between controllers and pilots using ground- or satellite -based radio relay stations.
A.2.20 Cross -
Checking. Cross- checking is the act of verification. Cross-checking involves
matching a set of test data against a set of master data to detect deviations in sequence or content.
A.2.21 Current Flight Plan (ICAO). Th e
flight plan, including changes, if any, brought about by
subsequent clearances.
Note: I n this AC, we use the term “ currently effective route clearance” to refer to
what ICAO Annex 2 calls the “current flight plan.”
A.2.22 D ead Reckoning (DR). The navigation of an airplane solely by means of computations
based on airspeed, course, heading, wind direction, groundspeed, and elapsed time.
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Appendix A
A-8 A.2.23 Electronic Flight Bag (EFB). An EFB is any device, or combination of devices, actively
displaying EFB applications. EFB applications are categorized as Type A or B, and can
be hosted on either portable or installed components. A list of EF B applications can be
found in the appendices of AC 120-76 .
A.2.24 Erosion of Longitudinal Separation. A loss of required horizontal separation between
aircraft operating at the same altitude, on the same oceanic routing, usually due to
improper speed control or failure to communicate to ATC in a timely manner any changes in ETAs in excess of 2 minutes.
A.2.25 Extended Diversion Time Operations (EDTO) (ICAO). Any operation by an airplane
with two or more turbine engines where the diversion time to an en route alternate aerodrome is greater than the threshold time established by the State of the Operator.
A.2.26 Extended Operations (ETOPS). An airplane flight operation, other than an all-cargo
operation in an airplane with two or more engines, during which a portion of the flight is
conducted beyond a time threshold identified in 14 CFR part 121 or 135, that is
determined using an approved one-engine- inoperative cruise speed under standard
atmospheric conditions in still air.
A.2.27 Fatigue Risk Management System (FRMS) (ICAO). FRMS is a data - driven means of
continuously monitoring and managing fatigue- related safety risks, based upon scientific
principles and knowledge as well as operational experience that aims to ensure relevant personnel are performing at adequate levels of alertness.
A.2.28 Flight Information Region (FIR) (ICAO). An airspace of defined dimensions within
which Flight Information Service (FIS) and alerting services are provided.
A.2.29 Flight Information Service (FIS) (ICAO). A service provided for the purpose of giving
advice and information useful for the safe and efficient conduct of flights.
A.2.30 Flight Level (FL) (ICAO). A surface of constant atmospheric pressure which is related to
a specific pressure datum (i.e., Standard Pressure—29.92 in Hg or 1013.2 hPa) and is separated from other such surfaces by specific pressure intervals.
A.2.31 Flight Operations Officer/Flight Dispatcher (ICAO). A person designated by the operator
to engage in the control and supervision of flight operations, whether licensed or not, suitably qualified in accordanc e with ICAO Annex 1, who supports, briefs, and/or assists
the PIC in the safe conduct of the flight.
A.2.32 General Aviation (GA). That portion of civil aviation that does not include schedul e d or
unscheduled air carriers or commercial space operations.
A.2.33 Global Navigation Satellite System (GNSS) (ICAO). A worldwide position and time
determination system that includes one or more satellite constellations, aircraft receivers, and system integrity monitoring, augmented as necessary to support the RNP for the intended operation.
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Appendix A
A-9 A.2.34 Global Positioning System (GPS). GPS refers to the worldwide positioning, navigation,
and timing determination capability available from the U.S. satellite constellation. Th e
service provided by GPS for civil use is defined in the GPS Standard Positioning Service
Performance Standard. GPS is composed of space, control, and user elements.
A
.2.35 Gross Navigation Error (GNE). A GNE is a lateral deviation of 10 NM or more from the
aircraft’s cleared route. Previously, the threshold for a GNE was 25 NM.
A.2.36 High Frequency (HF) Communications. Radio frequencies between 3 and 30 MHz used
for air/ground voice communications in overseas operations. HF communications (or, if supported, SATVOICE) capability is required for all IFR operations in controlled airspace when out of the range of VHF communications. If you are in doubt as to the VHF coverage along your intended route of flight, your aircraft should be equipped with HF communications (or SA TVOICE, if supported).
A.2.37 High Seas. The seas beyond the 12 NM from the baseline of a shore. Airspace over the
high seas is considered international airspace.
A.2.38 Instrument Meteorological Conditions (IMC) (ICAO). Meteorological conditions
expressed in terms of visibility, distance from clouds, and ceiling, less than the minima specified for visual meteorological conditions (VMC) .
A.2.39 International Civil Aviation Organization (ICAO). ICAO is a specialized agency of the
United Nations whose objective is to develop the principles and techniques of international air navigation and to foster planning and development of international civil air transport.
A.2.40 Journey Logbook (ICAO). A record of the flight operation, which should be retained in
order to maintain a continuous record of the last 6 months’ operations.
A.2.41 Large Height Deviations (LHD) . A deviation from your cleared altitude by 300 feet or
more.
A.2.42 Lateral Navigation (LNAV). A function of RNAV equipment that calculates, displays,
and provides lateral guidance to a profile or path.
A.2.43 Long-Range Navigation System (LRNS). An electronic navigation unit that is approved
for use under IFR as a primary means of navigation. An LRNS must have at least one source of navigational input s uitable for oceanic and remote continental navigation, such
as an INS or a GPS receiver.
A.2.44 Mach N
umber Technique. Describes a control technique used by ATC whereby turbojet
aircraft operating successively along suitable routes are cleared to maintain appropr iate
Mach numbers for a relevant portion of the en route phase of flight. The principal objective is to achieve improved utilization of the airspace and to ensure that separation between successive aircraft does not decrease below the established minima.
10/4/23 AC 91 -70C
Appendix A
A-10 A
.2.45 Maste r Document . A copy of the OFP , labeled as “Master,” on which the currently
effective route clearance is recorded, and which serves as the primary flightcrew
reference for updating the progress of the flight. It should list sequentially the waypoints
defining the route, the track and distance between each waypoint, and other information relevant to navigation along the cleared track.
A
.2.46 Master Minimum Equipment List (MMEL) (ICAO). A list established for a particular
aircraft type by the organization responsible for the type design with the approval of the State of Design containing items, one or more of which is permitted to be unserviceable at the commencement of a flight. The MMEL may be associated with special operating conditions, limitations, or procedu res.
A.2.47 Minimum Equipment List (MEL) (ICAO). A list that provides for the operation of
aircraft, subject to specified conditions, with particular equipment inoperative, prepared by an operator in conformity with, or more restrictive than, the MMEL established for the
aircraft type.
A.2.48 Navigation Specification (
NavSpec) (ICAO) . A set of aircraft and flightcrew
requirements needed to support PBN operations within a defined airspace. There are two kinds of NavSpec s:
A.2.48.1 Ar
ea Navigation (RNAV) Specification. A NavSpec ba sed on RNAV that
does not include the requirement for onboard performance monitoring and alerting, designated by the prefix RNAV (e.g., RNAV 5, RNAV 1).
A.2.48.2 Required Navigation Performance (RNP) Specification. A NavSpec based
on RNAV that includes the requirement for onboard performance monitoring and alerting, designated by the prefix RNP (e.g., RNP 4, RNP APCH).
A.2.49 North Atlantic High Level Airspace (NAT HLA). NAT HLA is that volume of airspace
(as defined in ICAO Doc 7030) between FL 285 and FL 420 within the O CAs of Bodo
Oceanic, Gander Oceanic, New York Oceanic East, Reykjavik, Santa Maria, and Shanwick, excluding the Shannon and Brest Ocean Transition Areas. Aircraft operators must obtain approval from their State of Registry to operate within NAT HLA.
A.2.50 Notice to Air Missions (NOTAM)
Domestic/International. A notice containing
information concerning the establishment, condition, or change in any aeronautical facility, service, procedure, or hazard, the timely knowledge of which is essential to personnel concerned with flight operations. NOTAMs are distributed via two methods: telecommunications (Class I Distribution) and other than telecommunications (Class II Distribution).
A.2.51 Oceanic Airspace. Airspace over the high
seas. Generally, “oceanic” is includ ed in the
airspace designation (e.g., Oceanic Control Area (OCA)), and direct controller-pilot VHF voice communications are not available. ATC is provided using at least some elements of procedural control in accordance with ICAO.
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Appendix A
A-11 A.2.52 Oceanic Area Control Cent er (OACC) . An ACC with responsibilities for providing ATS
in oceanic airspace. Responsibility for the provisions of ATS is delegated by ICAO to
various States based primarily upon geographic proximity and the availability of the required resources.
A
.2.53 Performance - based Communication (PBC) (ICAO). Communication based on
performance specifications applied to the provision of ATS . An RCP specification
includes c ommunication performance requirements that are allocated to system
components in terms of communication to be provided and associated, continuity, availability, integrity, safety, and functionality needed for the proposed operation in the context of a particular airspace concept.
A.2.54 Performance -
based Navigation (PBN) (ICAO). RNAV based on performance
requirements for aircraft operating along an ATS route, on an IAP, or in a designated airspace. Performance requirements are expressed in NavSpecs (RNAV specification, RNP specification) in terms of accuracy, integrity, continuity, availability, and functionality needed for the proposed operation in the context of a particular airspace concept.
A.2.55 Performance -
based Surveillance (PBS) (ICAO) . Surveillance based on performance
specifications applied to the provision of ATS . An RSP spe cification includes
surveillance performance requirements that are allocated to system components in terms
of the surveillance to be provided and associated data delivery time, continuity, availability, integrity, accuracy of the surveillance data, safety, and functionality needed
for the proposed operation in the context of a particular airspace concept.
A.2.56 Pilot in Command (PIC) (ICAO). The pilot designated by the operator, or in the case of
GA, the owner, as being in command and charged with the safe conduc t of a flight.
A.2.57 Procedural Control (ICAO). Term used to indicate that information derived from an A TS
surveillance system is not required for the provision of ATC service .
A.2.58 Procedural Separation (ICAO) . T he separation used when providing procedural control.
A.2.59 Reduced Vertical Separation Minima (RVSM) . RVSM separation minima are 1000 feet
vertical separation between FL 290 and FL 410 inclusive. Operators and aircraft must be authorized by the Administrator to operate in RVSM airspace. An operator may be authorized without application to the FAA when meeting the standards of part 91,
Appendix G , section 9. Alternatively, OpSpec/MSpec/LOA B046, Operations in Reduced
Vertical Separation Minimum (RVSM) Airspace , is available as a specific approval,
when needed for international operations. For additional guidance, refer to AC 91-85,
Authorization of Aircraft and Operators for Flight in Reduced Vertical Separation
Minimum (RVSM) Airspace.
A.2.60 Remote Continental Airspace . Airspace over land where VHF voice communications,
ATC surveillance (via radar or ADS -B), and reliable ground- based NAVAIDs are not
available. ATC is provided using procedural control and procedural separation, with LRCS .
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Appendix A
A-12 A.2.61 Required Communication Performance (RCP) Specification (ICAO). A set of
requirements for ATS provision, aircraft capability, and operations needed to support
PBC within a defined airspace.
A
.2.62 Requ ire d Navigation Performance (RNP) Specification (ICAO). A NavSpec based on
RNAV that includes the requirement for performance monitoring and alerting, designated by the prefix RNP (e.g., RNP 2, RNP 4, RNP APCH).
A.2.63 Required Surveillance Performance (RSP) Spec i
fication (ICAO). A set of ATS
provisions, including communication services and aircraft and operator requirements, needed for surveillance, supporting a performance-based operation within a defined airspace.
A.2.64 Special Use Airspace (SUA) . C
onsists of airspac e of defined dimensions where activities
must be confined because of their nature, or where limitations are imposed upon aircraft operations that are not a part of those activities, or both.
A.2.64.1 P
rohibited Areas. A prohibited area is an SUA designated under 14 CFR
part 73, within which no person may operate an aircraft without the
permission of the using agency.
A.2.64.2 R estricted Areas. A restricted area is an SUA designated under part 73,
within which the flight of aircraft, while not wholly prohibited, is subject to
restriction.
A.2.64.3 Warning Areas. A warning area is airspace of defined dimensions, extending from 3 NM outward from the coast of the United States, which contains activity that may be hazardous to nonparticipating aircraft. The purpose of such a warning area is to warn nonparticipating pilots of the potential danger. A warning area may be located over domestic or international waters or both.
A.2.65 T
arget Level of Safety (TLS) (ICAO). A generic term representing the level of risk that is
considered acceptable in particular circumstances.
A.2.66 Very High Frequency (VHF). The frequency band between 30 and 300 MHz. Portions of
this band, 108–118 MHz, are used for certain NAVAIDs, while 118–136 MHz are used for civil air/ground voice communications.
A.2.67 Visua l
Meteorological Conditions (VMC) . Meteorological conditions expressed in terms
of visibility, distance from cloud, and ceiling, equal to or better than specified minima.
A.2.68 Waypoint. A predetermined geographical position that is defined in terms of
latitude/longitude coordinates. Waypoints may be a simple named point in space or associated with existing NAVAIDs, intersections, or fixes. A waypoint is most often used to indicate a change in direction, speed, or altitude along the desired path. For purposes of RNAV procedures, waypoints are identified as either:
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Appendix A
A-13 A.2.68.1 Flyby Waypoint. Flyby waypoints are used when an aircraft should begin a
turn to the next course prior to reaching the waypoint separating the two route
segments. This is known as turn anticipation.
A.2.68.2 Flyover Waypoint. Flyover waypoints are used when the aircraft must fly over the point prior to starting a turn.
10/4/23 AC 91 -70C
Appendix B
B-1 APPENDIX B. SPECIAL AREAS OF OPERATION AND OPSPECs /MSPEC s/LOAs
B.1 Special Areas of Operation (SAO). SAOs are geographic areas having unique
characteristics that require the use of special equipment, procedures, and/or techniques to
safely conduct flight operations. The FAA requires certificated U.S. operators to obtain
operational author ization to fly in oceanic and remote continental airspace. The FAA
requires all operators to obtain operational authorization to fly in some or all of the SAOs, depending on operating part, as indicated in Table B-1, SAO- Related
OpSpecs/MSpecs/LOAs, and Ta ble B-2, Oceanic and Remote/General En Route
OpSpecs/MSpecs/LOAs. Currently, the FAA considers the following areas SAOs:
1. NAT HLA;
2. Central East Pacific Airspace;
3. North Pacific (NOPAC) Airspace ;
4. AMUs ; and
5. North Polar Area .
B.1.1 OpSpecs or MSpecs are the instruments for issuing operational authorization to U.S.
certificated operators. U.S. GA operators (i.e., those operating solely under part 91
(excluding part 91K )) obtain authorization through an LOA.
B.1.2 The tables below list the OpSpecs/MSpecs/LOAs associated with SAOs, as well as a number of OpSpecs and MSpecs related to the broader subject of oceanic and remote continental /general en route operations.
B.1.3 Absence of an “X” in the MSpec and/or Part 91 LOA applicability column
(e.g., OpSpec B041, North Atlantic Operations with Two -Engine Airplanes Under Part
121) indicates that an MSpec and/or LOA is not required for those operators who would ordinarily be issued MSpecs or LOAs.
Table B-1. SAO -Related OpSpecs/MSpecs/LOAs
Auth Applicability Title
OpSpec MSpec Part 91
LOA
B037 X X Operations in Central East Pacific (CEP) Airspace
B038 X X Operations in North Pacific (NOPAC) Airspace
B039 X X X1 Operations in North Atlantic High Level Airspace
(NAT HLA)
B040 X X Operations in Areas of Magnetic Unreliability
B055 X X North Polar Operations
D098 X2 Short -Term Operations in Airspace Requiring Specific
Approval
1 Part 91, B039 is required for NAT/HLA operations.
2 D098 can be used to authorize operations in oceanic/remote airspace, Reduced Vertical Separation Minimum
(RVSM) airspace, and in SAOs.
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Appendix B
B-2 Table B-2. Oceanic and Remote/General En Route OpSpecs/MSpecs/LOAs
Auth Applicability Title
OpSpec MSpec Part 91
LOA
A010 X X Aviation Weather Information
A014 X X Special En Route IFR Operations in Class G Airspace
A018 X Scheduled Passenger Helicopter Operations
A056 X X X3 Data Link Communications
A317 X Acceptance of a Fatigue Risk Management Plan
A354 X X X In-Trail Procedures (ITP) Using ADS -B In
B030 X X IFR Navigation Using GPS/WAAS RNAV Systems
B034 X X IFR Class I Terminal and En Route Navigation using Area Navigation
(RNAV) Systems
B036 X X X4 Oceanic and Remote Continental Navigation Using Multiple Long -Range
Navigation Systems
B041 X North Atlantic Operations with Two -Engine Airplanes Under Part 121
B043 X Special Fuel Reserves in International Operations
B044 X Planned Redispatch or Rerelease En Route
B045 X Extended Overwater Operations Using a Single Long -Range
Communication System
B046 X X X3 Operations in Reduced Vertical Separation Minimum (RVSM) Airspace
B050 X X X5 Authorized Areas of En Route Operations, Limitations, and Provisions
B054 X X X4 Oceanic and Remote Airspace Navigation using a Single Long -Range
Navigation System
B342 X Extended Operations (ETOPS) with Two -Engine Airplanes Under
Part 121/135
B344 X Extended Operations (ETOPS) in Passenger -Carrying Airplanes with
More Than Two Engines Under Part 121/135
B450 X X Sensitive International Areas
C055 X X Alternate Airport IFR Weather Minimums
D098 X6 Short -Term Operations in Airspace Requiring Specific Approval
H104 X X X Helicopter Offshore Instrument Operations: Offshore Standard Approach
Procedure (OSAP), Airborne Radar Approach (ARA), and Helicopter
En Route Descent Area (HEDA) Operations
3 Part 91, required for the respective operation outside the United States .
4 Part 91, either B036 or B054 is required to indicate oceanic and remote continental RNP capability , depending on
aircraft navigation system equipage.
5 Part 91 B050 LOA is called “Special Authorizations for Certain Areas of Operations,” and is used for areas where
U.S. civil aviation operations are prohibit ed.
6 D098 can be used to authorize operations in oceanic/remote airspace, RVSM airspace, and in SAOs.
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Appendix C
C-1 APPENDIX C. UNUSUAL WEATHER ACTIVITY
C.1 Volcanic Ash.
C.1.1 In 2010, a small volcano in Iceland erupted, spewing volcanic ash into the atmosphere.
Eyjafjallaj okull’s eruption stranded 8 million travelers and resulted in the largest airspace
shutdown since World War II. As a result, in 2012, ICAO produced the first edition of ICAO Doc 9974, Flight Safety and Volcanic Ash, which provides guidance for aircraft
operators when volcanic ash contamination may be a hazard for flight operations. Whenever your flight planned route approaches the vicinity of a volcanic ash cloud, you should understand the potentially catastrophic effects ingesting volcanic ash could have on your aircraft engines. Currently, nine Volcanic Ash Advisory Centers (VAAC) offer worldwide coverage of volcanic activity and provide valuable information to assist your trip planning efforts. For more in formation on the VAACs, go to
https://w ww.ssd.noaa.gov/VAAC/vaac.html .
Figure C -1. ICAO Volcanic Ash Advisory Centers
C
.1.2 Volcanic eruptions emit various gases along with magma, including sulfur dioxide (SO 2)
and hydrogen sulfide (H 2S). When SO 2 gas combines with water in the atmosphere, a
sulfate aerosol primarily composed of dilute sulfuric acid is formed. Flying through
sulfuric acid aerosols has caused crazing of acrylic windows, fading of exterior paint, and
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Appendix C
C-2 accumulation of sulfate deposits in engines. SO 2 gas is colorless, but under cer tain
conditions of reflection and refraction of sunlight, a sulfuric acid aerosol may be a visible
atmospheric feature, such as a layer of haze of variable color (brownish, yellowish, bluish, or whitish). Ash particles likely will be present in aerosol haz e but possibly in
minor or trace amounts.
C.1.3 Volcanoes are the only sources of large quantities of sulfur gases at cruise altitudes, and both types of sulfur gas have a noticeable smell. SO
2 is identifiable as the sharp, acrid
odor of a freshly struck match. H 2S, also known as sewer gas, has the odor of rotten eggs.
“Electrical smoke and fire” and SO 2 are two odors described as somewhat similar. Sulfur
gases may be detectable only for a short period of time because of “olfactory fatigue” (temporary loss of the ability to smell a particular odor). Inhalation of SO
2, even at low
concentrations (<5 ppm), can cause respiratory tract irritation, especially in people with asthma and chronic obstructive pulmonary disease.
C.1.4 If you smell sulfur gases in the cockpit, this may indicate volcanic activity that has n ot
yet been detected or reported and/or your possible entry into an ash-bearing cloud. After determining there are no secondary indications that would result from and indicate an electrical fire, you should establish whether the sulfur odor is transient or not.
C.1.5 You can best achieve this by donning your oxygen mask(s) and breathing 100 percent oxygen for the period of time that results in a complete change of air within the cockpit and also allows you to regain your sense of smell. After the appropriate time period,
remove your oxygen mask(s) and determine if the odor is still present. If you confirm the continued presence of sulfur gas, you should inform the controlling ATS unit and dispatch center as soon as practicable to request information about any relevant volcanic activity and the whereabouts of possible volcanic clouds. You do not have the means to determine directly whether or not the cloud is hazardous; therefore, you should seek to exit the cloud.
C.1.6 You might see other indications of volcanic ash such as fine dust in the aircraft, St. Elmo’s fire visible around your windshield, and/or a visible glow in the intake of your
engines. Your airspeed indications may also become unreliable as the ash contaminates your pitot/static system. Chapter 7 of the AIM recommends, in the event of encountering
an ash cloud, that pilots reverse course and reduce thrust (altitude permitting) to escape from the cloud, and to disengage aut othrottles (as applicable), turn on continuous
ignition, and turn on all bleed-powered systems so as to provide additional engine stall margin. In addition, the AIM discusses PIREPs related to volcanic ash activity and recommends you complete the V olcanic Activity Reporting (VAR) Form , found in
appendix 2 of the AIM. You should avoid flying in the vicinity of known volcanic ash. Attempting to overfly an ash plume is also potentially perilous, as an emergency descent could place the aircraft into the plume.
C.2 S
pace Weather.
C.2.1 The effects of space weather on aviation have generated an increasing amount of interest in recent years. Space weather most commonly impacts radio communications between
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Appendix C
C-3 your aircraft and ground stations. Space weather may also impact navigation signals from
space- based and ground-based transmitters as well as onboard avionics components.
Exposure to increased radiation levels during solar events has not been a noticeable issue, but it is a factor that you can plan for in order to pr otect your frequently flying
crewmembers and passengers.
C.2.2 The magnetic field around the Earth converges at the North and South Poles, allowing charged particles to access lower levels of the Earth’s atmosphere. These lower levels are the same levels used to fly international flights around the world. The aviation
community has shown increasing interest in this phenomenon at the poles as the expansion of polar routes has seen more and more flights susceptible to space weather.
C.2.3 The solar cycle is an approximat ely 11 -year period that is characterized by solar activity
that departs from the sun and has impacts on whatever celestial bodies are in the path of this space weather. The three effects of this weather are known as radio blackouts, geomagnetic storms, and solar radiation storms. These storms can have varying degrees
of short- and long-term impact on ground- based navigation signals, aircraft and aircrew
in flight, space- based transmitters, spacecraft, and space crew. The Space Weather
Prediction Center (SWP C) tracks these storms and issues space weather watches,
warnings, and alerts to inform the public of potential impacts.
Figure C -2. Example of a National Oceanic and Atmospheric Administration Scales
Activity Report
C
.2.4 Space weather alerts can be subscribed to through the SWPC Product Subscription Service and the following link: https://www.swpc.noaa.gov/forecasts .
C.2.5 Space Weather Advisory Information. Amendment 78 to ICAO Annex 3
(November 2018) introduced a requirement to issue space weather advisory information when necessitated by space weather events. The space weather advisory message is
similar in structure to advisory messages for tropical cyclones and volcanic ash clouds
issued by the tropical cyclone advisory centers and VAACs concerned.
C.2.6 S
pace Weather Advisory Centers issue space weather advisory information when there
are impacts to HF communications, communications via satellite, GNSS- based
navigation and surveillance systems, or when heightened radiation occurs.
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Appendix C
C-4 C.2.7 The advisory message informs the user of:
• The type of impact;
• The expected onset, or that the event is already in progress;
• The duration of the event;
• A generalized description of the spatial extent affected for the next 24 hours; and
• A description of the severity of the impact in moderate (MOD) or severe (SEV)
categories.
C.2.8 ICAO Annex 3 , Meteorological Service for International Air Navigation , and ICAO
Doc 10100, Manual on Space Weather Information in Support of International Air
Navigation, published in 2019, are additional references.
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Appendix D
D-1 APPENDIX D. SAMPLE OCEANIC CHECKLIST
D.1 Sample Abbreviated Oceanic Checklist. This sample abbreviated checkl ist is provided
for your reference. If you do not have an oceanic checklist, we encourage you to use this
sample and tailor it to your specific needs and approvals. This checklist focuses on an orderly flow and ways to reduce oceanic errors. You should also review the expanded checklist at paragraph D.2. An oceanic checklist should be published in your international
operations manual and evaluated and kept up- to-date as part of your Safety Management
System (SMS) , as applicable. The International Civil Aviation Organization (ICAO)
North Atlantic (NAT) oceanic checklists, which served as the foundation for our checklists, are available as a NAT OPS Bulletin, posted on the ICAO Europe/North Atlantic (EUR/NAT) region website, found at https://www.icao.int/EURNAT/Pages/welc
ome.aspx.
D.1.1 Flight Planning.
1. Communications, navigation, and surveillance flight plan codes and planning documents.
2. Oceanic documents.
3. Plotting/orientation chart—plot route coast out to coast in.
4. Equal Time Points (ETP)—plot.
5. Track message (current copy available for all crossings).
6. Note nearest tracks on plotting/orientation c hart.
7. Weather analysis—note en route wind, temperature , and turbulence forecasts as well
as ETP airport weather.
8. Review suitable navigational aids (NAVAID) for accuracy check prior to coast out .
D.1.2 P
reflight.
1. Master clock for all estimated times of arrival (ETA)/actual times of arrival (ATA).
2. Maintenance log —check for any communications, navigation, and surveillance or
Reduced Vertical Separation Minimum (RVSM) issues.
3. RVSM.
4. Altimeter checks (tolerance).
5. Wind shear or turbulence forecast.
6. Flight plan (check routing, fuel load, times, groundspeeds).
7. Dual long-range navigation system (LRNS) for oceanic and remote continental airspace operations.
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Appendix D
D-2 8. V
oice long- range communication system (LRCS) check (as applicable) :
a. Hi
gh frequency (HF) radio check.
b. S
atellite Voice ( SATVOICE ) operability check.
9. C
onfirm present position coordinates (best source).
10. Master Document symbols ( , , \, X).
11. LRNS programming:
a. Check navigation database currency and software version.
b. Independently verify navigation system/ flight management system (FMS)
programming.
c. Check expanded coordinates of oceanic waypoints.
d. Check leg course and distance (± 2° and ±2 nautical miles (NM)).
e. Upload winds, if applicable.
12. Groundspeed check.
D.1.3 Taxi and Prior to Takeoff.
1. Groundspeed check.
2. Present po sition check.
D.1.4 Climb Out.
1. Transition altitude —set altimeters to 29.92 inches (1013.2 hectopascals (hPa) ).
2. Calculate/Update ETAs on Master Document as duties permit.
D
.1.5 Prior to Oceanic Entry .
1. Navigation accuracy check —record results on Master Document .
2. Voice L RCS (HF selective calling system ( SELCAL) or SATVOICE Callback) check
with aeronautical radio station.
3. Confirm satellite communication s (SATCOM) data link is operational, if equipped.
4. Log on to Controller- Pilot Data Link Communication (CPDLC) and Automatic
Dependent Surveillance -Contract (ADS -C) 10 to 25 minutes prior, if equipped, unless
otherwise specified in the relevant Aeronautical Information Publication ( AIP).
5. Verify your Require d Navigation Performance (RNP) value is set.
6. Obtain oceanic clearance from appropriate clearance delivery and verify/cross- check
loading of route clearance into the navigation system.
a. Confirm assigned oceanic flight level (FL) and request climb or descent to be at
your assigned FL prior to oceanic airspace boundary.
b. Confirm FL, Mach, and route for crossing.
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Appendix D
D-3 c. Advise air traffic control (ATC) when able higher.
7. Revised clearance—update navigation system, Master Document , and
plotting/orientation chart.
Note: Check ex panded coordinates, course, and distance for new
route.
8. Check altimeters—record readings on Master Document .
9. Compass heading check (inertial navigation system (INS))—record.
D.1.6 After Oceanic Entry .
1. Squawk 2000—30 minutes after entry, if applicable.
2. Maintain assigned Mach.
3. Maintain assigned FL.
4. Very high frequency (VHF) radios—set to air -to-air and guard frequency.
5. Strategic Lateral Offset Procedure s (SLOP) —Depending on standard operating
procedures (SOP), fly cleared route or up to 2 NM to the right of ATC- cleared track.
Confirm procedures in the applicable AIP.
6. Altimeter checks —hourly.
D.1.7 Approaching Waypoints.
1. Confirm coordinates of subsequent waypoints.
Note: Verify that the active navigation system waypoint, as well as the next and
subsequent (“next plus 1”) waypoints, match your currently effective route
clearance . Confirm that the expanded (i.e., full latitude and longitude) coordinates
of the next and subsequent waypoints, as well as the course/heading and distance
to the waypoints, agree with your currently effective route clearance.
2. Confirm lateral navigation (LNAV)/navigation (NAV) is engaged.
D.1.8 Overhead Waypoints.
1. Confirm aircraft transitions to next waypoint.
Note: Check magnetic heading and distance against Master Document .
2. Confirm time to next waypoint.
Note: ETA changes in excess of 2 minutes (“3 minutes or more” in the NAT)
require ATC notification.
3. Make position report.
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Appendix D
D-4 Note: Record fuel remaining and current time on your Master Document .
D.1.9 Ten Minutes after Waypoint Passage . Cr oss-check navigational performance and course
compliance via one of the following methods:
1. Plotting method (see paragraph D.2.9).
2. Navigation display method (see paragraph D.2.9).
3. Alternative method accepted by the FAA (see paragraph 6.4.8).
D.1.10 Midway Between Waypoints.
1. Cross -check winds between Master Document , LRNS, and winds aloft charts.
2. Confirm time to next waypoint.
D.1.11 Coast In .
1. Remove strategic lateral offset prior to oceanic exit point.
2. Confirm routing beyond oceanic airspace.
3. Compare LRNS to ground- based NAVAID.
D.1.12 Descent . T ransition level —set altimeters to local altimeter setting (QNH).
D.1.13 Destination/Block -In.
1. Navigation accuracy check.
2. Altimetry system write -ups.
3. Data communications (CPDLC) problem reports.
D.2 Sample Expanded Oceanic Checklist. This sample expanded checklist is provided for
your reference. If you do not have an expanded oceanic checklist, we encourage you to
use this sample and tailor it to your specific needs and approvals. This checklist focuses on an orderly flow and ways to reduce oceanic errors. An oceanic checklist should be published in your international operations manual, and evaluated and kept up- to-date as
part of your SMS , as applicable.
D.2.1 Flight Planning.
D.2.1.1 Communications, Navigation, and Surveillance Flight Plan Codes and Planning Documents.
1. Review your ATC flight plan with emphasis on items 10A, 10B, and 18. Ensure that you properly filed the appropriate communications, navigation, and surveillance descriptors in items 10 and 18 of your flight plan.
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Appendix D
D-5 2. You should review your maintenance log and the minimum equipment list
(MEL) for system deferrals that may affect the communications, navigation, and surveillance capabilities of your aircraft. The “remarks and exceptions” column should provide the specific guidance for flight plan filing.
3. Your flight manual should include procedures to make flight plan amendments (or cancellations as appropriate) when your communications, navigation, and surveillance capabilities change phase prior to departure.
Note: Items 10 and 18 of the flight plan require more detail to indicate
your communications, navigation, and surveillance capabilities and authorizations. See paragraph 6.2.2.
D.2.1.2 Oceanic Documents. Operators are encouraged to develop a flight planning
checklist to ensure they have the necessary documents before departure. The checklist should include, as a minimum, the following:
1. Master Document.
2. Notices to Air Missions (NOTAM) for departure, destination, alternate(s);
Extended Operations (ETOPS) alternates (as applicable); and oceanic flight information regions (FIR).
3. Weather for departure, destination, alternate airports along the route of flig
ht, and ETOPS alternates (as applicable).
4. Track message(s).
5. Significant Weather (SIGWX) chart.
6. ETP(s), wind tables, or winds aloft charts for FLs or altitudes.
7. Global Positioning System (GPS) NOTAMs (as applicable).
8. Any applicable space weather watches, warnings, and alerts (see Appendix C , Unusual Weather Activity).
9. Volcanic ash information.
10. Pilot Weather Reports (PIREP).
11. Plotting/orientation charts.
D.2.1.3 Plotting/Orientation Chart.
D.2.1.3.1 You should use an oceanic plotting/orientation chart of appropriate scale that depicts published oceanic tracks.
D.2.1.3.2 ICAO groups that review oceanic errors have determined that the routine use
of a chart is an excellent way to reduce lateral errors. A chart can also help in the event of partial or total navigation system failure.
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Appendix D
D-6 D.2.1.3.3 You should read from the plotting/orientation chart back to the Master
Document when verifying data. Reading from the Master Document to the
chart can introduce “expectation bias,” where errors are missed because we
see what we expect to see.
D.2.1.3.4 Plot your currently effective route clearance from coast out to coast in. Make
sure you update this whenever your route clearance changes.
D.2.1.3.5 Note nearest oceanic tracks on your chart.
D.2.1.4 ETPs.
D.2.1.4.1 You should compute ETPs for contingencies such as medical divert, engine
loss, or rapid depressurization. You should also consider a simultaneous
engine loss and rapid depressurization.
D.2.1.4.2 Verify that planned ETP airports are adequate during time of flight operations.
D.2.1.4.3 You should annot ate the ETPs and associated alternates on your
plotting/orientation chart. When crossing ETPs, you should review with other crewmembers the appropriate diversion airport(s).
D.2.1.4.4 Your pilot procedures should also include a manual method for re -computing
ETPs either manually or through the use of an Electronic Flight Bag (EFB)
application . You should not enter ETPs in the active route of the LRNS
because additional waypoints, even if along the route, can produce nuisance out-of- conformance alerts in ATC ’s monitoring systems. Confusion about
these additional waypoints can also lead to deviations from the cleared route.
Note: ETPs may need to be recalculated when the cleared route
changes, when there are significant changes in FL s, and/or when
estimated time en route (ETE) to dest ination differs by more than
15 minutes from planned.
D.2.1.5 Track Message.
1. You must have a current track message even if you have filed for a “random route” (where at least part of the oceanic route is not on a published track) or if you filed above North Atlantic High Level Airspace (NAT HLA). Reviewing the date, effective time, and track message identifier ensures having a current track message on board. The track message identifier is linked to the Julian date.
2. You should also ensure that your flight planning and operational control process includes timely notification of crewmembers of any amendments to the daily track message.
3. When flying a random route, plotting adjacent tracks and/or crossing tracks can help your situational awareness in case you need to execute a
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Appendix D
D-7 contingency procedure. Monitoring traffic on the Traffic Alert and
Collision Avoidance System ( TCAS ) or Automatic Dependent
Surveillance- Broadcast ( ADS -B) In will further help your situational
awareness, as the same random routes are sometimes heavily used.
D.2.1.6 Weather Analysis. You should note en route wind, temperature, and
turbulence forecasts, as well as ETP airport weather, diversion/emergency
airport weather, volcanic activity, magnetic storms, and solar flares affecting your route of flight.
D.2.1.7 NAVAIDs. Review suitable NAVAIDs for accuracy check prior to coast out.
D.2.1.7.1 You should determine in advance a primary and secondary ground- based
NAVAID that you will use to verify the accuracy of your LRNS.
D.2.1.7.2 This planning may help you identify intended NAVAIDs that are limited or
NOTAM’d unusable and will help you when you depart airports close to oceanic airspace.
D.2.1.7.3 A latitude/longitude radar fix from ATC also meets the requirements for an accuracy check.
D.2.2 Preflight.
D.2.2.1 Master Clock. You must have a designated master clock on board
synchronized to Coordinated Universal Time (UTC) (generally via GPS). You must use this single time source, typically the FMS, for all ETAs and ATAs.
D.2.2.2 Maintenance Log. Pay particular attention to any write -ups that affect
communications, navigation, surveillance equipment, or RVSM requirements.
D.2.2.3 RVSM.
D.2.2.3.1 Required equipment to operate in RVSM airspace includes two primary independent altimetry sources, one altitude alert system, a nd one automatic
altitude control system.
D.2.2.3.2 In most cases, you are also required to have a functioning transponder that can
be linked to the primary altimetry source.
D.2.2.3.3 You should note any maintenance issues that could affect accurate altim etry.
D.2.2.4 Altimeter Checks.
D.2.2.4.1 Before taxi, you should set your altimeters to the airport QNH. Both primary
altimeters must read within ± 75 feet of a known elevation (e.g., field elevation ).
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Appendix D
D-8 D.2.2.4.2 The two primary altimeters must also agree with each other within the limits
noted in the aircraft operating manual.
D.2.2.5 Wind Shear or Turbulence Forecast.
D.2.2.5.1 You should review the operational flight plan (OFP) to determine where along
the route wind shear and/or turbulence are forecasted.
D.2.2.5.2 Forecast severe turbulence could lead ATC to stop using certain FLs.
D.2.2.5.3 Forecast severe turbulence may be incompatible with flight manual or operator limitations.
D.2.2.6 Flight Plan.
1. Ensure the flight plan designated as the Master Document includes the
date, type aircraft, fuel load, and performance requirements.
2. Cross -check the routing and forecast groundspeeds.
3. Ensure the Master Document and filed flight plan show the same routing.
4. Check the en route time on the Master Document against the distance to
your destination to ensure it is based on a reasonable groundspeed.
5. Compare the en route time against the total distance to ensure you have planned a reasonable fuel load.
D.2.2.7 LRNS.
1. You are typically required to have two independent operational LRNSs for oceanic and remote continental airspace operations. Operations Specification (OpSpec)/Management Specification (MSpec)/Letter of Authorization (LOA) B054/MB054, Oceanic and Remote Airspac e
Navigation Using a Single Long-Range Navigation System, identifies the oceanic and remote continental areas authorized for operations with a single LRNS.
2. A single FMS receiving inputs from two navigation sensors does not qualify as two LRNSs.
D.2.2.8 HF Check.
1. You should conduct an HF check on the primary and secondary HF radios (if equipped with two).
2. If possible, you should accomplish the HF checks on the ground or before entering oceanic airspace.
D.2.2.9 SATVOICE Check. You should perform the appropriate functional check if
you intend to use SATVOICE on your flight.
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Appendix D
D-9 D.2.2.10 Confirm Present Position Coordinates.
1. Both pilots should independently verify the present position coordinates
using either published ramp coordinates or by determining your position from the airfield diag ram.
2. You should not rely on the present position resident in your FMS from the previous flight.
D.2.2.11 Master Document Annotations. You should use consistent annotations on
your Master Document . See paragraph 6.4.4.2 for samples of this suggested
annotation scheme.
1. A circle next to th e waypoint designator indicates both pilots verified the
coordinates, courses , and distances. This would normally be done during
initial navigation system loading.
2. A backslash (“\ ”) over the circle denotes confirming a subsequent
waypoint’s coordinates and the track and distance to it. This would
normally be done approaching the active waypoint.
3. A forward slash (“/”) over the previously annotated backslash creates an
“X.” This indicates waypoint passage.
D.2.2.12 LRNS Programming.
D.2.2.12.1 Check navigation database currency and software version.
1. You should not fly with an expired database.
2. You should also confirm the software version of the database, to ensure the correct version is loaded.
D.2.2.12.2 Independently verify navigation system programming.
1. Two pilots should independently coordinate the loading and verification of flight plan entries.
2. Prior to loading the route, carefully cross -check the waypo int routing on
your Master Document against your filed flight to verify they are
consistent.
3. One pilot should load the route with all waypoints using the Master
Document. That same pilot should verify the route has been loaded correctly. Use a means independent of the data you loaded, such as checking the course/distance between waypoints against the Master Document.
4. A second pilot should independently check the entries by recalling and confirming the waypoint data against source information. This cross-che ck
should include comparing the waypoints loaded in the navigation system
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Appendix D
D-10 against both your filed flight plan and the Master Document .
Cross -checking course and distance against the Master Document will
further confirm the waypoints were loaded correctly.
5. T
he pilot accomplishing the cross-check should read from the navigation
system screen back to the Master Document when verifying data.
No
te: Reading from the Master Document to the FMS can introduce
“expectation bias” where errors are missed because we see what we
expect to see.
D.2.2.12.3
Check waypoint expanded coordinates (degrees and minutes).
1. Most navigation systems allow entering abbreviated oceanic coordinates. There have been cases when there was an error in the minutes, but crews
only checked the 7- character display label, or the 5 alphanumeric -
character waypoint name, neither of which displays minutes.
2. If you only verify the abbreviated coordinates, this could lead to a lateral error. You should check the expanded (i.e., degrees and minutes) coordinates of all oceanic waypoints.
D.2.2.12.4 Check course and distance.
1. To minimize oceanic errors, you should check magnetic course and distance between waypoints from oceanic entry to oceanic exit. You should establish a tolerance such as ± 2° and ± 2 NM.
2. The course and distance checks comparing the Master Document against
the LRNS can help detect errors that you may not have noticed by simply checking coordinates.
3. A discrepancy of more than 2° between the course in the Master Document and that in the LRNS may be due to the Master Docu ment
listing the mid -leg course, instead of the initial course. You should
recheck and verify any difference outside the ± 2° or ± 2 NM tolerance.
Note 1: Flight plan vendors typically allow an operator to list initial,
mid-leg, and/or end- point magnetic course in the Master Document.
An LRNS n ormally displays the present position magnetic course.
Both the Master Document and the LRNS use great circle routing between points. However, unless you are flying along a line of longitude or along the equator, your LRNS true course will gradually increa se or decrease as you progress along the great circle course. On a
typical oceanic leg (traversing 10° of longitude), the true course changes as much as 8° between the initial and end -points.
Note 2: Small discrepancies between the course in the LRNS and in
the Master Document can in some cases also be attributed to
differences in magnetic variation.
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Appendix D
D-11 4. You should also refer to a master source such as an en route chart to
confirm the accuracy of coordinates at the oceanic boundaries.
5. Confirm the total distance compute d by the LRNS is consistent with your
Master Document .
6. If your navigation system waypoint sequencing is limited, number the Master Document waypoints. Use the same numbering sequence for all
navigation systems in use.
D.2.2.12.5 Upload winds. Some LRNS units allow the crew to upload projected winds.
This procedure allows more accurate reporting of ETA.
D.2.2.13 Groundspeed Check. You should note the groundspeed before taxiing the
aircraft. You should expect the groundspeed to read zero knots.
Note: This procedure is a goo d practice to detect an error that may be
developing in the LRNS.
D.2.3 T
axi and Prior to Takeoff.
D.2.3.1 Groundspeed Check. During taxi, pilots should again check the groundspeed
to see if it is reasonable.
D.2.3.2 Present Position Check. You should also conduct a present pos ition check
after leaving the gate.
1. Check for a gross difference between this present position and your gate
coordinates.
2. This check may alert you to a possible error in the LRNS database that you can investigate/correct prior to takeoff.
D.2.4 C
limbout.
D.2.4.1 Transition Altitude.
1. You should brief the transition altitude published on the departure or
approach charts, or provided via Automatic Terminal Information Service
(ATIS).
2. After climbing through the transition altitude, you should reset the altimeters to 29.92 inches or 1013.2 hP a.
D.2.4.2 Calculate/Update ETAs on Master Document. If the departure airport is
near the oceanic entry point, you should calculate/update your ETAs from departure to destination, time and duties permitting, during climb out, or otherwise prior to oceanic entry, by adding the ETEs to the most recent a ctual
time of arrival (ATA). You should note these updated ETAs on the Master
Document.
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Appendix D
D-12 Note: This is an excellent cross -check of ETAs computed by your
LRNS.
D.2.5 P rior to Oceanic Entry .
D.2.5.1 Navigation Accuracy Check.
D.2.5.1.1 Before oceanic entry, you should check the accuracy of your LRNS against a
suitable ground-based NAVAID, as applicable. A latitude/longitude radar fix
from ATC can also support a navigation accuracy check in lieu of a NAVA ID.
D.2.5.1.2 You should record the results of the accuracy check on the Master Document ,
with the time and position.
1. A large discrepancy between the ground- based NAVAID, or ATC radar
fix, and your LRNS should cause you to consider whether your navigation
system will navigate within the degree of accuracy you indicated in your
flight plan (e.g., RNP 4 or 10), or that is otherwise expected by ATC. If you have any doubts about your navigation accuracy, it is better to notify ATC early, so the controller can adjust separation accordingly.
Note: Crews should not attempt to correct an error by performing an
air alignment or by manually updating the position of the LRNS, because this has often resulted in worsening the problem.
2. You should establish a navigation accuracy check tolerance based on your type of LRNS. In any case, follow flight manual procedures. As applicable, rank each navigation system by accuracy.
3. Record aircraft compass/inertial/radio magnetic indicator (RMI) headings and note differences and deviations. A compass deviation check is
particularly important if your aircraft is not equipped with an FMS.
D.2.5.1.3 Select the most accurate navigation system for coupling to the autopilot.
D.2.5.2 HF Checks.
1. If you were unable to accomplish the HF checks on the ground, you
should accomplish these checks before oceanic entry.
2. Accomplish a SELCAL check prior to oceanic and remote continental airspace entry and then again at each control area (CTA) boundary. Check your SELCAL even when your CPDLC is working normally.
D.2.5.3 SATVOICE Callback Check.
1. When using SATVOICE to communicate with ATC via New York Radio or San Francisco Radio, the FAA requires a SATVOICE Callback Check.
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Appendix D
D-13 2. Co
ntact the appropriate aeronautical radio station and request a
SATVOICE Callback Check, indicating which satellite provider you are
using if you filed both Inmarsat and Iridium (codes M1 and M3). See sample transcript in paragraph
D.2.5.4 SATCOM Data Link Check. If you plan on using SATCOM data link, you
should check that your SATCOM data link is operational before oceanic entry.
D.2.5.5 Lo
g on to CPDLC and/or ADS -C. If you are approved to use CPDLC and/or
ADS -C, you should log on to the appropriate data authority 10 to 25 minutes
prior to the boundary, unless otherwise specified in the relevant AIP.
D.2.5.6 V
erify Your RNP Value. Verify that the RNP value set in your flight
management computer (FMC) is no higher than that required for the route of flight and reflects the RNP capability you indicated in your flight plan. For example, if you filed indicating RNP 4 capability, you should set an RNP value of 4.0 even though the route may only require RNP 10.
D.2.5.7 O
btain Oceanic Clearance.
1. At
least two pilots should be involved in the clearance receipt and
read-back process, one actively and one monitoring. When obtaining the
clearance via radio, we recommend both pilots wear headsets because they typically have better acoustic quality than loudspeakers.
Note: Consult the AIP for the oceanic FIR you are transiting to
determine how and when to obtain your oceanic clearance. Timing differs depending on whether you receive your clearance via voice or data li nk.
2. You should include your requested FL , as well as the maximum FL you
are able to accept, in your initial clearance request.
3. Both pilots should independently copy the clearance. Each pilot then cross-checks the routing, FL, and Mach number assigned for the crossing. If there are any differences, contact the Air Traffic Service (ATS ) provider
for clarification.
4. Read all waypoint coordinates back to the ATS provider in detail. Ensure the ATS provider acknowledges your correct read back. Always cross- check each detail of the clearance with your Master Document .
5. Pilots should ensure the aircraft enters oceanic airspace at the altitude assigned in the oceanic clearance (this may be different than the domestic cleared FL). Request climb or descent, as required, in order to be at your cleared oceanic FL prior to entering oceanic airspace.
6. Verify/cross -check the route clearance is properly programmed into
LRNS.
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Appendix D
D-14 D.2.5.8 Revised Clearance. (See also paragraph 6.4.1.7.)
1. The number one scenario that leads to a pilot deviation from the assigned
routing is when the ATC clearance is different from the oceanic route reques ted with the filed flight plan.
2. When issuing revised clearances, ATC often, but not alwa ys, notes that
“route (/altitude) has been changed.” You should be particularly cautious when receiving such a revised clearance.
3. Both pilots should separately copy and confirm the new routing, comparing with each other and confirming any inconsistencies w ith the
ATS provider.
4. One pilot reprograms (and executes) your navigation system and updates the Master Document and plotting/orientation chart, crossing out the old
waypoints and plotted route and replacing them with the updated information.
5. A second pilot cross -checks the revised clearance with the reprogrammed
route in the navigation system (checking the expanded coordinates: degrees and minutes), the updated Master Document , and the updated
chart.
6. You should check the expanded coordinates, magnetic course, and distance between the new waypoints as noted in paragraph D.2.2.12
above. Unless you receive a new Master Document from your dispatcher,
you should update the Master Document with the new courses and
distances. Some operators use commercially available tables specifically made for this purpose, or use an onboard flight planning system (e.g., an application in an EFB) to independently calculate course and distance, for
comparison against the navigation system .
7. Thoroughly brief relief pilots on the new clearance prior to them assuming coc
kpit duties. We highly recommend the relief pilots also independently
cross- check th e currently effective route clearance against the navigation
system , Master Document , and chart.
D.2.5.9 Altimeter Checks.
1. Prior to oceanic entry, you must check the two primary altimeters are reading within 200 feet of each other (or lesser value if specified in your flight manual). Conduct this check while at level flight.
2. You should also note the stand- by altimeter reading.
3. Record the altimeter readings and time on the Master Document .
Note: Cross -checking altimeters and airspeed indicators can reveal
pitot- static discrepancies and is especially advisable in areas of known
or forecast icing.
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Appendix D
D-15 D.2.5.10 Compass Heading Check (INS).
1. If inertial systems are your only means of long -range navigation (LRN),
we recommend you conduct a compass heading check and record the
results.
2. If a p roblem develops over water, this check can also aid you in
determining the most accurate compass.
D.2.6 A fter Oceanic Entry .
D.2.6.1 Squawk 2000.
1. Thirty minutes after oceanic entry, you should change your squawk to 2000, if applicable.
2. There may be regional differences in transponder requirements. For
example, aircraft transiting through in the New York West o ceanic c ontrol
area (OCA) or the Reykjavik OCA are expected to maintain the last
assigned squawk.
D.2.6.2 Maintain Assigned Mach. Some oceanic clearances include a specific Mach.
In such cases, ATC expects you to maintain the exact Mach assigned
(i.e., there is not an implied speed range you can fly).
1. Longitudinal separation standards applied by ATC frequently require crews to maintain the assigned Mach until otherwise advised. Economy (ECON) or Long Range Cruise (LRC) modes of the FMS may cause the aircraft to deviate from the assigned Mach.
2. Controllers will assign a true Mach. In most cases, the true Mach is the indicated Mach. Some aircraft may require a correction factor.
D.2.6.3 Maintain Assigned FL. You must report to ATC when departing your current
FL.
D.2.6.4 VHF Radios. After going beyond the range of the assigned VHF frequency,
you should set your radios to air- to-air (123.45) and guard frequency (121.5).
D.2.6.5 SLOP. Your SOPs should include SLOP for all oceanic crossings. NOTAMs,
State AIPs, and other flight planning guidanc e will indicate where exceptions
apply and where procedures differ.
1. Executing SLOP reduces the risk associated with two aircraft using their
highly accurate navigation systems to navigate head -on between the same
two points, where one of those aircraft is at the wrong altitude.
24 Regulatory references are § 91.183 and ICAO Annex 2, paragraph 3.6.3. U.S. AIM , pa ragraph 5-3- 2, describes
when ATC specifies these reports.
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Appendix D
D-16 2. Executing SLOP also helps aircraft avoid wake turbulence. Depending
upon winds aloft, coordination between aircraft may be necessary.
3. This procedure, which distributes traffic between the route centerline and up to 2 NM right of cent erline, greatly reduces collision risk by the nature
of its randomness.
a. Operators that have an automatic offse t capability should fly up to
2 NM right of the centerline.
b. Aircraft that do not have an automatic offset capability (that can be programmed in th e navigation system) should fly the centerline only.
D.2.6.6 Hourly Altimeter Checks. The two primary altimeters should continue to
read within 200 feet of each other (or lesser value if specified in your flight manual).
Note: We recommend that you record these hourly checks on the
Master Document with the readings and times. This information can
help you determine the most accurate altimeter if you develop an
altimetry problem. Some operators incorporate these altimeter checks
into their “overhead waypoint” checks.
D.2.6.7 Rout ine Monitoring.
1. Specify which FMS pages, or other displays of navigation information, that individual flightcrew members are charged with monitoring
(e.g., a cross- track error or time/distance).
2. You should use the non-steering navigation system to display cross- track
error and track angle error, if available.
3. If your navigation system provides a predicted ETA capability, you should take full advantage of that function in order to track the accuracy of ETAs
and provide reminders for performing the “approaching waypoint” and
“10 minutes following waypoint passage” cross-checking procedures.
D.2.7 A
pproaching Waypoints . Confirm coordinates of subsequent waypoints.
D.2.7.1 Within a few minutes prior to crossing an oceanic waypoint, you should
confirm the expanded coordinates of the next and subsequent (“next + 1”) oceanic waypoints.
D.2.7.2 You should accomplish this check by comparing the coordinates in your navigation system against your Master Document (as updated based on your
currently effective route clearance), as well as verifying that the course/heading and distance in the navigation system matches your Master
Document. Draw a diagonal through the circle next to the waypoint on your
Master Document .
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Appendix D
D-17 D.2.7.3 Confirm your autopilot steering is appropriately engaged (L NAV/NAV).
D.2.8 O verhead Waypoints.
D.2.8.1 Confirm aircraft transitions to the next waypoint.
1. When overhead an oceanic waypoint, you should ensure that your aircraft
properly transitions to the next leg.
2. You can confirm this by noting the magnetic heading and distance to the next waypoint as compared against the Master Document (as updated
based on your currently effective route clearance ).
D.2.8.2 Position report:
1. Use the standard format for voice position reports to ATC.
2. You should also note and record your fuel status on the Master Document
at each oceanic waypoint.
Note: This is especially important if the cleared route and FL differ
significantly from the filed flight plan.
D.2.9 T
en Minutes After Waypoint Passage . Cross-check navigational performance and course
compliance by one of th e following methods:
D.2.9.1 T he “plotting” method is appropriate for all aircraft navigation configurations.
1. Verify your plotting/orientation chart reflects the currently effective route
clearance .
2. Plot your present latitude/longitude and record the time on your chart.
3. You should plot your position using coordinates from the nonsteering LRNS.
4. Investigate/take corrective action if your plotted position does not agree with your currently effective route clearance.
5. Using the steering LRNS, verify the next waypoint is consistent with the currently effective route clearance.
6. Verify your autopilot steering mode is in LNAV/NAV or other appropriate mode to ensure steering to the next intended waypoint.
D.2.9.2 The “navigation display” method is appropriate for and available for use in aircraft equipped with an operable FMS.
1. Confirm the aircraft symbol is on the programmed route on the navigation display (at smallest scale).
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Appendix D
D-18 2. Check system -generated cross- track deviation or similar indication of any
deviation from the programmed route of flight.
3. Using the steering LRNS verify the “TO” waypoint is consistent with your
currently effective route clearance.
4. Investigate/take correction action to address any anomalies or unexpected deviations.
5. Verify your autopilot steering mode is LNAV/NAV or other appropriate mode to ensure steering to the next intended waypoint.
D.2.9.3 You may use an alternate method with FAA acceptance.
D.2.10 Mi
dway Between Waypoints.
D.2.10.1 Cross- Check Winds.
1. We recommen d you cross- check the winds midway between oceanic
waypoints by comparing the Master Document , LRNS, and winds aloft
chart.
2. This cross -check will also assist with situational awareness and in the
event your navigation capability is degraded to the point where you need to dead reckon (DR).
D.2.10.2 Confirm ETA. We recommend you confirm your ETA to the next waypoint.
Note: Promptly advise ATC if your ETA has changed greater than 2
minutes (“3 minutes or more” in the NAT) (for aircraft providing automatic position reporting via an ADS -C logon, pilots should
discontinue voice position reports).
D.2.11 C
oast In .
D.2.11.1 Remove strategic lateral offset. You must remove the strategic lateral offset prior to exiting oceanic airspace at coast in. We recommend you include this as a checklist item.
D.2.11.2 Confirm routing beyond oceanic airspace. Before entering the domestic route structure, confirm your routing and speed assignment.
Note: Crews experiencing loss of communication leaving oceanic
airspace should follow guidance published in the applicable State AI P.
D.2.11.3 Compare LRNS to ground-based NAVAID (as applicable depending on your
equipage).
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Appendix D
D-19 1. When departing oceanic airspace and acquiring ground- based NAVAIDs,
you should note the accuracy of your LRNS compared to the position
information provided by those NAVAIDs.
2. You should note discrepancies in your maintenance log.
D.2.12 D escent .
D.2.12.1 Transition Level. During the approach briefing, you should note the
transition level on the approach plate or verify with ATC. Reset your altimeters to QNH (or QFE, if used) when descending through the transition
level. You should confirm whether the altimeter setting is based on inches of mercury , hectopascal ( hPa), or (less common) millimeters (mm) of mercury .
D.2.13 D
estination/Block -In.
D.2.13.1 Navigation Accuracy Check. When arriving at your destination gate, you should note any drift or circular error in your LRNS.
1. A GPS primary means system normally should not exceed 0.27 NM for the flight.
2. Some inertial systems may drift as much as 2 NM per hour.
Note: If tolerances are exceeded, make an appropriate entry in the
maintenance log.
D.2.14 A
ltimetry System Write -Ups. Record any problems in the altimetry system, altitude alert,
or altitude hold in the maintenance log.
Note: A TS authorities closely monitor RVSM airspace for any large height
deviations (LHD) . If your aircraft no longer meets RVSM standards, you must not
flight plan into RVSM airspace.
D.2.15 CP DLC Write -Ups. As applicable, note problems with the data communication system,
providing sufficient detail so a problem report can be submitted to the data link
monitoring agency, if warranted. FMS and SATCOM logs are helpful in investigating
anomalies, and sometimes are available only for the most recent activity.
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Appendix E
E-1 APPENDIX E. IATA IN- FLIGHT BROADCAST PROCEDURE
E.1 Introduction. The International Air Transport Association (IATA) developed the
following procedures to promote flight safety over portions of the African continent and
some adjacent waters. IATA last updated the procedures in 2019. You should check the IATA website for any further updates prior to flight in the affected airspace .
E.2 Background. In many flight information region s (FIR ) in the African -Indian Ocean
Region (AFI), both fixed and mobile aviat ion communication systems have either not
been implemented or operate well below the required reliability. This has an impact on the proper provision of Air Traffic Services (ATS ), especially with regard to flight
information services (FIS). Consequently, an AFI Regional Technical Conference has
determined that the IATA In -Flight Broadcast Procedure ( IFBP ) should be used within
AFI designated FIRs as an interim measure, until such time as communications facilities affecting the FIRs in question have been improved.
E.3 Designated Frequency in AFI. In the AFI region , the designated frequency for the IFBP
is 126.9 MHz.
E.4 Area of Application. It is recommended that the IFBP be applied in the following FIRs
and airspaces:
Asmara Lusaka
Brazzaville* Mogadishu
Kano Niamey*
Khartoum N’Djamena*
Kinshasa Tripoli**
Luanda Dakar
* Brazzaville, Niamey, and N’Djamena FIRs provide CPDLC service ; however these
FIRs are maintained in the IFBP area of applicability to accommodate users’ requirement for linear boundaries to the extent feasible.
** Tripoli FIR mandated IFBP within their entire FIR, hence their IFBP region extended
from north of latitu de 30° N to cover the entire Tripoli FIR.
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Appendix E
E-2 Figure E -1. Map of IFBP Area of Applicability
E.
5 Listening Watch.
E.5.1 A listening watch should be maintained on the designated frequency (126.9 MHz)
10 minutes before entering the designated airspace until leaving this airspace.
E.5.2 For an aircraft taking off from an aerodrome located within the lateral limits of the
designated airspace, listening watch should start as soon as appropriate and be maintain ed
until leaving the airspace.
E.6 Broadcast Intervals.
E.6.1 A broadcast should be clearly pronounced in English:
• Ten minutes before entering a FIR within an IFBP region;
• Upon entering a FIR within the IFBP region;
• As soon as practicable when departing from an aerodrome located within the IFBP
region;
• Ten minutes prior to crossing or joining an ATS route or crossing an airway or
waypoint;
• Every 20 minute s;
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Appendix E
E-3 • Before a change in FL;
• Upon reach ing the intended FL; and
• At any other time consider ed necessary by the pilot.
Note 1: In the interest of reducing congestion on the IFBP frequency, pilots may
exercise discretion to omit closely spaced repetitive IFBP reports. However,
broadcast intervals should not exceed 20 minutes.
Note 2: The IFBP frequency must be clos ely monitored at all times when in the
region (i.e., do not turn off or reduce volume levels on the transmitting/receiving
frequency ).
E.7 Broadcast Procedure.
A broadcast message should be structured as follows:
“ALL STATIONS”
“THIS IS ABC123 [ flight number] in the XXX [ FIR name] FIR ”
Position AAAAA
(current position) at … : … UTC FL … (Altitude maintaining)
“DIRECTION Bound”
(direction) on XX987 (airway)
Estimating BBBBB
(next position; waypoint or
crossing airway if no waypoint) at … : … UTC
CCCCC NEXT
(subsequent position; way point
or crossing airway if no
waypoint)
E.8 Additional Operating Procedures.
E.8.1 C hanges of Cruising Level. Changes of cruising level are considered necessary by pilots
to avoid traffic conflicts, for weather avoidance, or for other valid operational reasons.
When cruising level changes are unavoidable , all available aircraft lighting which would
improve the visual detection of the aircraft should be displayed while chan ging levels.
E.8.2 Collision Avoidance . If on receipt of a traffic information broadcast from another aircraft,
a pilot decides that immediate action is necessary to avoid an imminent collision risk to
their aircraft, and this cannot be achieved in accordance wi th the right -of-way provisions
of ICAO Annex 2, they should:
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Appendix E
E-4 • Unless an alternative maneuver appears more appropriate, climb or descend 500 ft.
• Display all available aircraft lighting which would improve the visual detection of the
aircraft.
• As soon as possible, reply to the broadcast advising action being taken, and specify
altitude maintaining .
• Notify the action taken on the appropriate ATS frequency.
• As soon as your situation has bee n rectified, resume allocated FL, notify ing the action
on the appropriate ATS frequency.
E.8.3 Normal Position Reporting Procedures. N ormal position reporting procedures should be
continued at all times, regardless of any action take n to initiate or acknowledge a traffic
information broadcast.
E.8.4 O peration of Transponders. Pilots shall ensure that transponder procedures as contained
in ICAO Doc 8168 , Procedures for Air Navigation Services —Aircraft Operations, are
complied with and, in the absence of other directions from ATC, operate the transponder
on Mode A and C code 2000.
E.8.5 Use of TCAS . In accordance with ICAO Doc 7030 , Regional Supplementary Procedures,
Airborne Collision Avoidance System ( ACAS) II shall be carried and operated in the AFI
region by all civil fixed -wing turbine-engine aircraf t having a maximum takeoff mass
exceeding 5,700 kg or maximum approved passenger seating configuration of more than 19. IATA therefore promotes the use of a working TCAS for aircraft when operating
within the AFI region; and pilots shall select traffic adv isory/Resolution Advisory (RA)
mode at maximum range.
E.8.6 U
se of Strategic Lateral Offset Procedure s (SLOP) . Use of SLOP is promoted in the AFI
region.
E.9 Enforcement.
E.9.1 All airlines operating in the AFI region are requested to:
• Ensure that their air crews are fully briefed on the procedure and area of application
described.
• Ensure that charts and flight documentation are fully amended to reflect the
procedures.
E.9.2 Any operator reported to IATA as not applying the procedure shall be contacted immediately, informed of the procedure, and requested to apply it.
E.9.3 Attention is drawn to the fact that during the Haj pilgrimage period the number of east-west flights in the north -central part of the AFI region increases dramatically, and
with it the risk of ATS incidents and the importance of adopting the IFBP.
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Appendix E
E-5 E.10 Review. The procedure and its area of applicability are reviewed by the IATA AFI
Regional Coordination Group (RCG) from time to time and the FIRs in which t he
procedure is to be appli ed may be included or excluded as necessary.
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Appendix F
F-1 APPENDIX F. SPECIAL PROCEDURES FOR IN- FLIGHT CONTINGENCIES IN
OCEANIC AIRSPACE
Note 1: The source document for these procedures is ICAO Doc 4444 ,
Procedures for Air Navigation Services —Air Traffic Management. The U.S.
Aeronautical Information Publication ( AIP) publishes these procedures as well.
There are slight format or wording diffe rences, but the procedures are identical in
substance.
Note 2: The FAA recommends that operators carry a quick reference card
c
ontaining the applicable contingency procedures. Figure F-1, Special Procedures
for In -Flight Contingencies in Oceanic Airspace (Non- Weat her) provides a useful
graphic and can be used for this purpose.
Figure F- 1. Special Procedures for In -Flight Contingencies in Oceanic Airspace
(Non -Weather)
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Appendix F
F-2 F.1 Introduction. Although all possible contingencies cannot be covered, these procedures
provide for the more frequent cases such as:
• Inability to comply with assigned clearance due to meteorological conditions, aircraft
performance, or pressurization failure.
• En route diversion across the prevailing traffic flow.
• Loss of, or significant reduction in, the required navigation capability when operating in airspace where the navigation performance accuracy is a prerequisite to the safe conduct of flight operations.
F.1.1 The procedures are applicable primarily when descent and/or turn back or diversion is
required. The pilot shall take action as necessary to ensure the safety of the aircraft, and the pilot’s judgment shall determine the sequence of actions to be taken, having regard to the prevailing circumstances. Air traffic control (ATC) shall render all possible assistance.
F.1.2 While the procedures described here are applicable in “high seas” (international) oceanic areas, pilots operating in remote continental airspace may also at times need to deviate from an ATC clearance. In U.S. sovereign airspace, “captain’s authority” is granted via 14 CFR part 91, § 91.123 to deviate in an emergency. ICAO Annex 2 generally forms the
basis of flight rules in sovereign airspace throughout the world, and grants the same
deviation authority in Paragraph 3.6.2, Adherence to Current Flight Plan. Given that in remote continental air space, long- range communication systems (LRCS) are used, the
oceanic contingency procedur es described here may be useful in instances where relevant
State Aeronautical Information Publication (AIP ) procedures are not available. Oceanic
contingency procedures help when a pilot urgently needs to deviate from an ATC clearance but is unable to coordinate the deviation quickly enough with ATC.
F.2 G
eneral Procedures (5 Nautical Miles (NM )).
Note: On November 5, 2020, the International Civil Aviation Organization
(ICAO) changed oceanic contingency procedures globally, to use 5 NM offsets
for the general procedures, and an altitude deviation beginning at 5 NM for the weather contingency procedures.
F.2.1 If an aircraft is unable to continue the flight in acco rdance with its ATC clearance, a
revised clearance should be obtained, whenever possible, prior to initiating any action.
F.2.2 If prior clearance cannot be obtained, the following contingency procedures should be employed until a revised clearance is received .
1. Leave the cleared route or track by initially turning at least 30 degrees to the right or to the left in order to intercept and maintain a parallel, same direction track or route offset of 9.3 km (5.0 NM). The direction of the turn should be based on one or more of the following:
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Appendix F
F-3 • Aircraft position relative to any organized track or route system;
• The direction of flights and FLs allocated on adjacent tracks;
• The direction to an alternate airport;
• Any strategic lateral offset being flown; and
• Terrain clearanc e.
2. The aircraft should be flown at a n FL and an offset track where other aircraft are less
likely to be encountered .
3. Maintain a watch for conflicting traffic both visually and by reference to the Airborne
Collision Avoidance System ( ACAS ) (if equipped) lea ving ACAS in Resolution
Advisory ( RA) mode at all times, unless aircraft operating limitations dictate
otherwise .
4. Turn on all aircraft exterior lights (commensurate with appropriate operating
limitations).
5. Keep the Secondary Surveillance Radar ( SSR) transp onder on at all times and, when
able, squawk 7700, as appropriate .
6. As soon as practicable, the pilot shall advise ATC of any deviation from assigned clearance.
7. Use whatever means is appropriate (i.e. , voice and/or Controller -Pilot Data Link
Communications ( CPDLC) ) to communicate during a contingency or emergency.
8. If voice communication is used, the radiotelephony distress signal (MAYDAY) or urgency signal (PAN PAN) , preferably spoken three times, shall be used, as
appropriate .
9. When emergency situations are communicated via CPDLC, the controller may respond via CPDLC. However, the controller may also attempt to make voice communication contact with the aircraft.
10. Addit ional guidance on emergency procedures for controllers and radio operators,
and flightcrew, in data link operations can be found in ICAO Doc 10037, Global
Operational Data Link (GOLD) Manual.
11. Establish communications with and alert nearby aircraft by broad casting, at suitable
intervals on 121.5 megahertz ( MHz ) (or, as a backup, on the inter -pilot air -to-air
frequency 123.45 MHz) , and where appropriate on the frequency in use: Aircraft
Identification (ACID) , the nature of the distress condition, intention of the person in
command, position (including the Air Traffic Service (ATS ) route designator or the
track code, as appropriate) and flight level (FL).
12. The controller should attempt to determine the nature of the emergency and ascertain any assistance that may be required. Subsequent ATC action with respect to that aircraft shall be based on the intentions of the pilot and overall traffic situation.
10/4/23 AC 91 -70C
Appendix F
F-4 F.2.3 A ctions to B e Taken Once Offset F rom Track . The pilot’s judgment of the situation and
the need to ensure the saf ety of the aircraft will determine if the actions outlined in
paragraph F.2.3.2, item 1 or 2, will be taken. Factors for the pilot to consider when
diverting from the cleared route or track without an ATC clearance include, but are not
limited to:
• Op eration within a parallel track system;
• The potential for User Preferred Routes (UPR) parallel to the aircraft’s track or route;
• The nature of the contingency (e.g., aircraft system malfunction); and
• Weather factors (e.g. , convective weather at lower FLs).
F.2.3.1 If po ssible, maintain the assigned FL until established on the 9.3 km (5.0 NM)
parallel, same direction track or route offset. If unable, initially minimize the rate of descent to the extent that is operationally feasible.
F.2.3.2 Once established on a parallel, same d irection track or route offset by 9.3 km
(5.0 NM), either:
1. Descend below FL 290, establish a 150 m (500 ft) vertical offset from
those FLs normally used, and proceed as required by the operational situation or, if an ATC clearance has been obtained, procee d in accordance
with the clearance; or
Note: Descent below FL 290 is considered particularly applicable to
operations where there is a predominant traffic flow (e.g., east –west)
or parallel track system where the aircraft’s diversion path will likely cross adjacent tracks or routes. A descent below FL 290 can decrease the likelihood of conflict with other aircraft, ACAS RA events, and delays in obtaining a revised ATC clearance.
2. Establish a 150 m (500 ft) vertical offset (or 300 m (1000 ft) vertical offset
if above FL 410 from those FLs normally used) and proceed as required by the operational situation or, if an ATC clearance has been obtained, proceed in accordance with the clearance.
Note: Altimetry system error may lead to less than actual 500 ft
vertical separ ation when the procedure above is applied. In addition,
with the 500 ft vertical offset applied, ACAS RAs may occur.
F.3 General Weather Deviation Procedures (5 NM). The following procedures are
intended for deviations around adverse meteorological conditions.
Note: On November 5, 2020, ICAO changed oceanic contingency procedures
globally, to use 5 NM offsets for the general procedures, and an altitude deviation beginning at 5 NM for the weather contingency procedures.
10/4/23 AC 91 -70C
Appendix F
F-5 F.3.1 G eneral .
F.3.1.1 When weather deviation is required, the pilot should initiate communications
with ATC via voice or CPDLC. A rapid response may be obtained by either:
1. Stating “WEATHER DEVIATION REQUIRED” to indicate that priority
is desired on the frequency and for ATC response; or
2. Requesting a weather deviation using a CPDLC lateral downlink message.
F.3.1.2 When necessary, the pilot should initiate the communications using the
urgency call “PAN PAN” (preferably spoken three times) or by using a CPDLC urgency downlink message.
F.3.1.3 The pilot shall inform ATC when we ather deviation is no longer required, or
when a weather deviation has been completed and the aircraft has returned to its cleared route.
F.3.2 A
ctions to B e Taken When Controller−Pilot Communications A re Established .
F.3.2.1 The pilot should notify ATC and request clea rance to deviate from track or
route, advising when possible, the extent of the deviation requested. The flightcrew will use whatever means is appropriate (i.e. , CPDLC and/or voice)
to communicate during a weather deviation.
Note: Pilots are advised to contact A TC as soon as possible with
requests for clearance in order to provide time for the request to be
assessed and acted upon.
F.3.2.2 ATC should take one of the following actions:
1. When appropriate separation can be applied, issue clearance to deviate
from track; or
2. If there is conflicting traffic and ATC is unable to establish appropriate
separation, ATC should:
a. Advise the pilot of inability to issue clearance for the requested
deviation;
b. Advise the pilot of conflicting traffic; and
c. Request the pilot’s intentions.
F.3.2.3 The pilot should take one of the following actions:
1. Comply with the ATC clearance issued; or
2. Advise ATC of intentions and execute the procedures provided in
paragraph F. 3.3 below.
10/4/23 AC 91 -70C
Appendix F
F-6 F.3.3 A ctions to B e Taken if a Revised ATC Clearance Cannot B e Obtained .
Note: The provisions of this paragraph apply to situations where a pilot needs to
exerci se the authority of a pilot- in-command under the provisions of ICAO
Annex 2, paragraph 2.3.1.
Figure F-2. Special Procedures for In -Flight Weather Contingencies
F
.3.3.1 If the aircraft is required to deviate from track or route to avoid adverse
meteorological conditions, and prior clearance cannot be obtained, an ATC
clearance shall be obtained at the earliest possi ble time. Until an ATC
clearance is received, the pilot shall take the following actions:
Note: Figure F- 2 provides a general illustration of the weather
deviation scenario. Table F-1 shows the altitude o ffset portion of the
procedures. 1. I
f possible, deviate away from an organized track or route system;
2. Establish communications with and alert nearby aircraft by broadcasting,
at suitable intervals: ACID, FL, position (including ATS route designator or the track code) and intentions, on the frequency in use and on
121.5 MHz (or, as a backup, on the inter- pilot air -to-air frequency
123.45 MHz);
3. Watch for conflicting traffic both visually and by reference to ACAS (if
equipped);
4. Turn on all aircraft exterior lights (commensurate with appropriate
operating limitations);
5. For deviations of less than 9.3 km (5.0 NM) from the originally cleared
track or route , remain at a level assigned by ATC;
10/4/23 AC 91 -70C
Appendix F
F-7 6. For deviations greater than or equal to 9.3 km (5.0 NM) from the
originally cleared track or route, when the aircraft is approximately 9.3 km (5.0 NM) from track, initiate a level change in accordance with Table F-1, Altitude Offset When Denied Clearance to Deviate 9.3 km (5.0 NM) or More (5 NM Procedures);
7. If the pilot receive s clearance to deviate from cleared track or route for a
specified distance and subsequently requests but cannot obtain a clearance to deviate beyond that distance, the pilot should apply an altitude offset in accordance with Table F-1 before deviating beyond the cleared distance;
8. When returning to track or route, be at its assigned FL when the aircraft is within approximately 9.3 km (5.0 NM) of the centerline; and
9. If contact was not established prior to deviating, continue to attempt to contact ATC to obtain a clearance. If contact was established, continue to keep ATC advised of intentions and obtain essential traffic information.
Note: If, as a result of actions taken under the provisions of
paragraph F.3.3.1, the pilot determines that there is another aircraft at
or near the same FL with which a conflict may occur, then the pilot is expected to adjust the path of the aircraft, as necessary, to avoid conflict.
Table F -
1. Altitude Offset Wh en Denied Clearance to Devi ate 9.3 km (5.0 NM) or More
(5 NM P rocedures)
Originally Cleared
Track or Route
Center Line Deviations
≥ 9.3 km (5.0 NM) Level Change
EAST
(000° - 179°
magnetic) LEFT DESCEND
90 m (300 ft)
RIGHT CLIMB
90 m (300 ft)
WEST
(180° - 359°
magnetic) LEFT CLIMB
90 m (300 ft)
RIGHT DESCEND
90 m (300 ft)
F.4 Contingency Considerations for Unexpected Closure of an Oceanic ATC Facility .
F.4.1 F lig hts W ithin Any O ceanic A irspace . Continue as last cleared and contact the next ATC
unit as soon as possible with a position report. Flightcrews should use extreme caution and use all available means to detect any conflicting traffic.
10/4/23 AC 91 -70C
Appendix F
F-8 F.4.2 Flights Approaching Any O ceanic A irspace When the Contingency I s Activated .
F.4.2.1 Not in R eceipt of an O cean ic Clearanc e (Where A pplicable). Flights not in
receipt of an oceanic clearance should land at an appropriate aerodrome or, if
feasible, request clearance to avoid the affected oceanic control a rea (OCA).
F
.4.2.2 In R eceipt of an Acknowledged O ceanic C learance ( Where Applica ble).
F
.4.2.2.1 Aircraft operating with a received and acknowledged oceanic clearance can, at the flightcrew’s discretion, continue, but should expect limited ATC service within the affected OCA. Due to the uncertainty surrounding the contingency situation, flightcrews should, if possible, consider seeking a clearance to reroute around the affected OCA.
F.4.2.2.2 Flightcrews are requested to broadcast traffic information in the blind to other flights/stations on 121.5 MHz and on 123.45 MHz (or 126.9 MH z as
appropriate in designated International Air Transport Association (IATA) broadcast areas), in order to exchange position information. A continuous air-ground voice communication watch, per ICAO Annex 2, paragraph 3.6.5,
must be maintai ned.
F.4.2.2.3 Operators and flightcrews should be advised that ATC may invoke the ICAO
traffic information broadcast by a ircraft (TIBA) procedure, with flightcrew
member broadcasts in the following form:
ALL STATIONS (call sign), FLIGHT LEVEL (number) (or
CLIMBING/DESCENDING TO FLIGHT LEVEL (number)) (direction) (ATS route) (or DIRECT FROM (position) TO (position)) POSITION (position) AT (time) ESTIMATING (next reporting point, or the point of crossing or joining a designated ATS route) AT (time) (call sig n) FLIGHT
LEVEL (number) (direction).
TIBA calls should be provided by a flightcrew member at the following times:
1. Ten minutes before entering the designated airspace or, for a flightcrew
member taking off from an aerodrome located within the lateral limits of
the designated airspace, as soon as appropriate after takeoff;
2. Ten minutes prior to crossing a reporting point;
3. Ten minutes prior to crossing or joining an ATS route;
4. At 20- minute intervals between distant reporting points;
5. Two to five minutes, where possible, before a change in FL;
6. At the time of a change in FL; and
7. At any other time considered necessary by flightcr ew.
10/4/23 AC 91 -70C
Appendix F
F-9 F.4.3 Additional Cons iderations :
1. Flights involved in level change should complete the maneuver as soon as possible in
accordance with the clearance.
2. Mandatory position reports should be accomplished via high frequency (HF) or Satellite V oice (SATVOICE) until directed by ATC.
3. Flights equipped with Future Air Navigation System 1/A (FANS 1/A) or equivalent should communicate using HF voice or SATVOICE while attempting to reestablish CPDLC connection in airspace where ATC services are susp ended.
4. Flights may request their flight dispatch offices provide traffic information and/or
forward positio n reports to the relevant OCA.
F.4.4 Additional Recommendations. Consistent with AIP recommendations, should flightcrews
encounter situations that are not covered by regulati on, they are expected to exercise
good judgment in whatever action they elect to take. Additionally, flightcrews should take the following actions:
1. Monitor for traffic visually and by using Traffic Alert and Collision Avoidance System ( TCAS ) or Automatic D ependent Surveillance- Broadcast (ADS -B) In.
2. Ensure all appropriate exterior lights are operable and turned on.
3. Monitor and use, as appropriate, relevant communication channels (e.g., 121.5/123.45 or 126.9 MHz in oceanic airspace) to include HF frequencies for traffic and situational awareness, and SATVOICE and/or data link.
F.4.5 References:
• IATA’s In -Flight Broadcast Pro cedures (IFBP) (see App endix E of this AC).
• TIBA (refer to ICAO Annex 11 , Attachment B).
• Two-way radio communications failure (refer to § 91.185 and AIP , GEN 3 .4,
paragraphs 12 and 13).
• North Atlantic (NAT) communications failure (refer to AIP, ENR 7.8, paragraph 4
and ICAO NAT Doc 006 , Air Traffic Management Operational Contingency Plan,
North Atlantic Region ).
• Pacific communications failure (refer to ICAO Annex 2 , paragraph 3.6.5.2 .2, and
ICAO Doc 7030 , Regional Supplementary Procedures, PAC para graph 9.3).
• Special Procedures for In -Flight Contingencies in Oceanic Airspace (refer to the U.S.
AIP, ENR 7.3 ).
10/4/23 AC 91 -70C
Appendix G
G-1 APPENDIX G. SUGGESTED SUBJECTS FOR INCLUSION IN OCEANIC AND
INTERNATIONAL PROCEDURES AND/OR AN OPERATIONS MANUAL
Note 1: This list is for reference only. It is not intended to be all -inclusive. You
are encouraged to use this list when creating procedures and/or o perations
manuals and keeping them current. The complexity of your operations and
operational approvals will dictate which items on this list are applicable or need to be expanded. Please see the North Atlantic (NAT) Resource Guide for United
States Operators; Pacific Resource Guide for U.S. Operators ; or West A tlantic ,
Gulf of Mexico, and Caribbean Resource Guide for U.S. Operators for the most
current version of this list.
Note 2: You should establish and maintain a robust process to remain current in
oc
eanic and international operations. This continuous analysis or process is one
component of an operator ’s SMS.
G.1 Regulations, ICAO Guidance, and References.
G.1.1 Title 14 CFR .
G.1.2 Applicable ICAO Documents (current editions). Find the following documents at the
ICAO store at https://store.icao.int :
• ICAO Doc 4444, Procedures for Air Navigation Services—Air Traffic Management.
• ICAO Doc 7030, Regional Supplementary Procedures.
• ICAO Doc 9574, Manual on a 300 m (1000 ft) Vertical Separation Minimum
Between FL 290 and FL 410 Inclusive.
• ICAO Doc 9613, Pe rformance -based Navigation (PBN) Manual.
• ICAO Doc 10037, Global Operational Data Link (GOLD) Manual (CPDLC, ADS- C).
• ICAO Annex 2, Rules of the Air.
• ICAO Annex 6, Operation of Aircraft (Parts I, II, and III, as applicable).
• ICAO NAT Doc 007, North Atlantic Operations and Airspace Manual.
G.1.3 Aeronautical Information Publication (AIP), United States of America —Rel evant
Material .
G.1.4 Applicable FAA ACs (current editions):
• AC 90-105, Approval Guidance for RNP Operations and Barometric Vertical
Navigation in the U.S. National Airspace System and in Oceanic and Remote
Continental Airspace.1
1 See, in particular, AC 90 -105, Chapter 8, Paragraph 8.4.3, Pilot Knowledge.
10/4/23 AC 91 -70C
Appendix G
G-2 • AC 90-117 , Data Link Communications.
• AC 91 -70, Oceanic and Remote Continental Airspace Operations.
• AC 91-85 , Authorization of Aircraft and Operators for Flight in Reduced Vertical
Separation M inimum (RVSM) Airspace.
• AC 120-42 , Extended Operations (ETOPS and Polar Operations) (also refer to
14 CFR part 121, § 121.161 ).
• AC 135-42 , Extended Operations (ETOPS) and Operations in the North Polar Area
(also refer to 14 CFR part 135, § 135.364 ).
G.1.5 Miscellaneous:
• FAA North Atlantic (NAT) Resource Guide for United States Operators ; Pacific
Resource Guide for U.S. Operators ; or West Atlantic , Gulf of Mexico, and Caribbean
Resource Guide for U.S. Operators , Required Navigation Performance (RNP) PDF,
ICAO Paris, and Eurocontrol (SKYbrary).
• State Department Travel Alerts and Transportation Safety Administration (TSA)
Alerts.
• Electronic Flight Bag (EFB) instructions and procedures; applications (as applicable).
G.1.6 NOTAM s, GPS NOTAMs, FAA International Notices, and Special Federal Aviation
Regulations (SFAR).
G.2 Navigation. Continental (formerly Class I) versus Oceanic and Remote navigation; and
navigation by means of DR.
G.3 Flight Planning.
G.3.1 North American Routes (NAR) .
G.3.2 Track Messages.
G.3.3 ATC Flight Plans . Explanation and correct codes.
G.3.4 Operational Flight Plan (OFP) (also known as Computer Flight Plan (CFP) ):
• Comparison to ATC flight plan.
• Basic cross checks (fuel, groundspeed, winds).
• ETP and points of safe return.
• Fuel requirements (in particular, ICAO Annex 6) and reduced fuel (OpSpecs B043,
B044, and B343).
G.3.5 SAO Requirements .
10/4/23 AC 91 -70C
Appendix G
G-3 G.3.6 Use of Plotting/Orientation Chart and Master Document.
G.3.7 Weather Radar (WX) Charts :
• TAF, Aviation Routine Weather Report (METAR), and SIGWX.
• 700 millibars (mb), 500 mb, 400 mb, 300 mb, 250 mb.
• Approved source(s) : NWS and EWINS.
G.3.8 D riftdown —Terrain, Alternates, ETOPS .
G.3.9 WGS 84 or Approved Equivalent Compliance.
G.4 State Operating Restrictions.
G.5 Reduced Vertical Separation Minimum (RVSM):
• General description.
• Metric assignments (e.g., China).
• Minimum required equipment.
• Contingencies.
• Forecasts, tropopause, temperature deviations.
G.6 Accident/Incident.
G.6.1 T itle 49 of the Code of Federal Regulations (49 CFR):
• Part 175, Carriage by Aircraft ( Hazardous Materials Regulations).
• Part 830, Notification and Reporting of Aircraft Accidents or Incidents and Overdue
Aircraft, and Preservation of Aircraft Wreckage, Mail, Cargo, and Records (National
Transportation Safety Board).
G.6.2 Contingencies:
• Weather deviatio ns.
• General contingencies.
• Lost communications, TIBA, IFBP.
• Degraded navigation, DR.
• Activation of AMVER system, emergency l ocator t ransmitter (ELT).
• Depressurization/ Oxygen supply.
• Intercept, hijack.
10/4/23 AC 91 -70C
Appendix G
G-4 G.6.3 Use of Navigation System:
• Review of Airplane Flight Man ual Supplements (AFMS) for capabilities/limitations.
• Description of GPS, GPS NOTAMs , RAIM prediction, FDE.
• Description of INS, time limits.
• Currency/software version of database.
• Loading and cross- checks.
• Independent verification.
• Contingencies/fault codes.
G.6.4 Oceanic Crossing :
• Oceanic checklist (Appendix D ).
• Master time source.
• Clearance- FIR differences.
• Navigation accuracy check.
• RVSM checks.
• Approaching, overhead, and post-position waypoint checks.
• Position report—ETA tolerance.
• Ten-minute post -position check.
G.6.5 Altimetry :
• QNH, QNE, and QFE.
• Transition a ltitude (TA)/ transition l evel (TL).
• MB, hPa .
G.6.6 Transponder Operations. Regional (e.g., NAT , Pacific) requirements.
G.6.7 Communications, Navigation, and Surveillance.
1. Airspace requirements (RNP 10/4/2).
2. Data link (ADS -C, CPDLC).
3. Voice communications and aeronautical radio stations (VHF, HF, SATVOICE).
4. Reduced separation —trials and implementations.
G.6.8 Strategic Lat eral Offset Procedure s (SLOP) .
G.6.9 Volcanic Ash . Source of information and crew notification.
10/4/23 AC 91 -70C
Appendix G
G-5 G
.6.10 Space Weather. Warnings, alerts, and advisories (see Appendix
C, Unusual Weather
Activity).
G
.6.11 Operational Control:
• OpSpec A008—Operational Control.
• OpSpec A009—Airport Aeronautical Data.
• OpSpec/MSpec A010—Aviation Weather Information.
G.6.12 O ceanic Speed Control:
• Tolerance, areas applicable.
• ATC Mach Number Technique.
• Operations Without Assigned Fixed Speed (OWAFS).
G.6.13 O ceanic Errors:
• Revised clearance/conditional clearances.
• CPDLC route clearances.
Advisory Circular Feedback Form
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Standards Directives Management Officer at 9-AWA-AFB-120-Directives@faa.gov.
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