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Saudi eAIP GEN 2.1 — Measuring System, Aircraft Markings, Holidays
Reproduced for study. Always verify against the official GACAR at gaca.gov.sa.
Saudi eAIP, AIRAC AMDT 05/26 — effective 14 MAY 2026. Verify against the current AIP at aimss.sans.com.sa before any operational use.
GEN 2 TABLES AND CODES
GEN 2.1 MEASURING SYSTEM, AIRCRAFT MARKINGS, HOLIDAYS
2.1.1 Units of measurement
The table of units of measurement shown below will be used by aeronautical stations within Jeddah FIR for air and ground operations.
2.1.2 Temporal reference system
General
Coordinated Universal Time (UTC) and the Gregorian calendar are used by Saudi air navigation services and in publications issued by the Aeronautical Information Services in Saudi Arabia. Reporting of time is expressed to the nearest minute, e.g. 12:40:35 is reported as 1241.
2.1.3 Horizontal reference system
2.1.3.1 Name / designation of system
All published geographical coordinates indicating latitude and longitude are expressed in terms of the World Geodetic System - 1984 (WGS-84) geodetic reference datum.
2.1.3.2 Parameters of the Projection
Projection is expressed in terms of Universal Transverse Mercator (UTM).
For measurement of
Units used
Distance used in navigation, position reporting, etc. generally in excess of 2 nautical miles
Nautical miles and tenths
Relatively short distances such as those relating to aerodromes (e.g. runway lengths)
Meters
Altitudes, elevations and heights
Feet
Horizontal speed including wind speed
Knots
Vertical speed
Feet per minute
Wind direction for landing and taking off
Degrees magnetic
Wind direction except for landing and taking off
Degrees true
Visibility including runway visual range
Kilometers or meters
Altimeter setting
Hectopascal
Temperature
Degrees Celsius
Weight
Metric tons or kilograms
Time
Hours and minutes, beginning at midnight UTC
2.1.3.3 Ellipsoid
An ellipsoid is expressed in terms of the World Geodetic System - 1984 (WGS-84) ellipsoid.
2.1.3.4 Datum
The World Geodetic System - 1984 (WGS - 84) is used.
2.1.3.5 Area of application
The area of application for the published geographical coordinates coincides with the area of responsibility of the AIS, i.e. the entire territory of Saudi Arabia as well as the airspace over the high seas encompassed by the Jeddah FIR in accordance with the regional air navigation agreement.
2.1.3.6 Use of an asterisk to identify published geographical coordinates
An asterisk (*) will be used to identify those published geographical coordinates that have been transformed into WGS-84 coordinates but whose accuracy of original field work does not meet the accuracy requirements in GACA Regulations.
2.1.4 Vertical reference system
2.1.4.1 Name/designation of system
The vertical reference system corresponds to mean sea level (MSL).
2.1.4.2 Geoid model
The geoid model used is the Earth Gravitational Model 1996 - (EGM - 96).
2.1.5 Aircraft nationality and registration marks
The nationality mark for aircraft registered in Saudi Arabia is the two-letter group HZ. The nationality mark is followed by a hyphen and a registration mark consisting of a combination of up to three letters or numbers, e.g. HZ - ABC.
2.1.6 Public holidays
Name
Date/Day
Founding day
22 February each year
National day
23 September each year
Eid AI Fitr
25th Ramadan to 5th of Shawal
Eid Al Adha
5th to 15th Al Haj month
Weekend
Friday and Saturday
Note 1:
An AIC will be published at the beginning of each Gregorian year showing the Eid Al Fitr and Al Adha converting to Gregorian dates.
Note 2:
Some administrative services may not be available and banks and other institutions may not be open during public holidays.
2.1.7 Saudi Arabia National Spatial Reference System (SANSRS)
SANSRS is a consistent reference stem that defines Cartesian coordinates, longitude, latitude, height, scale, gravity and orientation throughout the Kingdom of Saudi Arabia.
A system which allows users to precisely determine and express locations in the kingdom of Saudi Arabia, as well as to quantify changes of the Earth and its gravity field in space and time.
Designed to meet national economic, social and environmental needs and is used in all applications and services for positioning in horizontal and vertical directions. Also, all existing geospatial products and services are referenced to it.
In general, the SANSRS consists of the following components:
Geodetic Reference Frame (KSA GRF).
Vertical Reference Frame (KSA-VRF).
Geoid Model (KSA-GEOID).
More information about the realization is provided on the General Authority for Survey and Geospatial Information (GEOSA) website:
www.geosa.gov.sa
2.1.7.1 Transformation from KSA-GRF17 to WGS-84
Transformation details
Name:
KSA-GRF17 to WGS-84(1)
CODE in EPSG:
9383
VERSION:
GCS-Sau
Variant:
1
Accuracy (m):
1
Source CRS:
KSA-GRF17
Target CRS:
WGS-84
Transformation method:
Position Vector transformation (geog2D domain)
Method is reversible:
Yes
Parameter
Value
Unit
Reversible
X-axis transition
0
meter
Yes
Y-axis transition
0
meter
Yes
Z-axis transition
0
meter
Yes
X-axis rotation
-8.393
milliarc-second
Yes
Y-axis rotation
0.749
milliarc-second
Yes
Z-axis rotation
-10.276
milliarc-second
Yes
Scale difference
0
parts per million
Yes
2.1.7.2 Description of the national geoid model KSA-GEOID21
The Mean Sea Level (MSL) correspond to the national geoid model KSA-GEOID21 encompasses the entire Kingdom of Saudi Arabia. The spatial resolutions (equiangular spacing in WGS-84 geodetic coordinates) are as follows:
Minimum Latitude: 13°
Maximum Latitude: 34°
Minimum Longitude: 33°
Maximum Longitude: 57°
Latitude Step: 0.020°
Longitude Step: 0.025°
The accuracy of this model is 25 cm.
2.1.7.3 Transformation Between the National Geoid Model and EGM96
MSL values can be transformed to and from EGM96 using the following transformation grid:
https://aimss.sans.com.sa/assets/FileManagerFiles/Transformation%20grid/KSA-GEOID21_to_EGM96_dms.csv
This transformation grid covers the Jeddah FIR, with rows and columns defined by the geographical coordinates provided in the margin, expressed in degrees and minutes.
To transform MSL values and geoid undulation between EGM96 and KSA-GEOID21 for any given Position is in (Degrees), the height value is in (Meters), use the following formulas:
MSL value (EGM96] = MSL value (KSA-GEOID21] - value shown in grid
Geoid Undulation (EGM96] = Geoid Undulation [KSA-GEOID21) + value shown in grid
Note
: The grid of geoid heights expressed in KSA-Geoid2 l and has been calculated, and it differs from the geoid transformation model. These formulas can be applied only to the KSA-Geoid21 - EGM96 transformation grid.
Fly GACA is an independent educational platform. It is not affiliated with, endorsed by, or operated by the General Authority of Civil Aviation (GACA) or the Government of the Kingdom of Saudi Arabia. The official and authoritative source for all civil aviation regulations, publications, and aeronautical information is always GACA. Always verify against the latest official GACA publication at gaca.gov.sa.