NTSB Safety Alert SA-064 - Pilot Weather Reports (PIREPs) Pay It Forward

Pilot Weather Reports (PIREPs) : Pay It Forward

More and better PIREPs enhance safety for all

The problem

• Sparse reporting and inaccurate or incomple te information adversely affect the usefulness

of PIREPs (brief reports from pilots describing observed in -flight weather conditions) for

improving weather forecasts and advisories and helping pilots avoid weather hazards .1

• Pilots submit relatively few PIREPs compared to overall traffic volume (see figure) .

o Pilots may be unaware that PIREPs of all weather conditions are important , including

good or “as forecasted ” weather .

o Pilots may lack confidence in their ability to assess weather .

o Pilots may not be proficient or comfortable with the various PIREP submission

methods .

o Pilots may think that their PIREPs will not be disseminated to others.

Figure. The approximate volume of air traffic nationwide captured in one instant in July 2016. By comparison, only a

few dozen PIREPs were submitted during a 1 -hour period about this time. (Image excerpted from the flightradar24

website.)

1 The problems listed here and related safety recommendations are documented in the National Transportation

Safety Board ’s (NTSB) Special Investigation Report SIR -17/02, Improving Pilot Weather Report Submission and

Dissemination to Benefit Safety in the National Airspace System .

SA-064 June 2017 • PIREPs often contain inaccurate or incomplete information .

o Time or location errors in a PIREP greatly diminish its usefulness to pilots for strategic

and tactical flight planning and to meteorologists for verifying forecasts or issu ing

advisories .

o Incomplete information or t he use of n onstandard terminology or coding when

reporting weather phenomena and intensity classifications significantly reduces a

PIREP’s effectiveness because computers (and sometimes humans ) cannot interpret

the information . For example, such errors may prevent weather programs from

automatically creating a graphical depiction of the PIREP.

Importance of PIREPs to flight safety

Historically, weather -related accidents involving general aviation aircraft that encountered poor

visibility have a higher fatality rate than all other types of accidents, and accidents involving

encounters with in -flight turbulence account for the most inj uries to passengers and flight attendants

on board US air carriers. As documented in the NTSB ’s SIR-17/02 , PIREPs play a vital role in

improving the weather information used to support flight safety for all aircraft operations —small and

large —to avoid inadvertent encounters with hazardous weather and prevent such accidents :

• The NTSB issued numerous safety recommendations in March 2017 (in SIR-17/02 ) to

improve how air traffic controllers, flight service station specialists, and others record and

disseminate PIREPs; however, to improve the effectiveness of th e PIREP system, pilots

must also do their part to increase the quantity and improve the quality of their reports.

• PIREPs are one of the most important sources of information that weather forecasters use

to verify or amend aviation forecast and advisory pro ducts .

• A single PIREP can influence a weather forecaster’s decision to issue (or discontinu e) a

hazardous weather advisory, such as an AIRMET or a SIGMET, and/or amend its area.

• Weather researchers use PIREPs to improve the accuracy of global forecast models and

turbulence and icing weather advisory products.

• Other pilots, flight -planning personnel (such as dispatchers), and air traffic controllers need

PIREPs when performing stra tegic and tactical route planning to avoid weather hazards.

PIREP s of null /negative or light conditions can help air traffic controllers decide whether to

route aircraft through blocks of altitude that they had previously routed traffic around.

What can pilots do?

• Provide PIREPs when workload permits. Even late -reported PIPEPs (filed after landing) are

valuable if the time and location of the weather phenomena are reported accurately .

• Report the time and location of the weather phenomena as precisely as possible .

• Use standard terminology and/or coding when reporting the type and intensity of weather

phenomena. Refer to official Federal Aviation Administration (FAA) publications (links

provided below) for guidance.

• Although you should be as complete and concise as possible when giving a verbal PIREP

to an air traffic controller or flight service station specialist , don’t be deterred if you are unsure

of the format . The person who receives your PIREP can request clarification if needed .

• Remember that PIREPs for null and light conditions , as well as conditions that are “as

forecasted, ” are as important as reports of hazardous or unexpected weather.

SA-064 June 2017 • Familiarize yourself with all the different methods of submitting PIREPs . In addition to

providing reports verbally, other options include electronic submission tool s, such as

web-based applications or certain aircraft equipment .

• Use whichever PIREP -submission method seems most appropriate for the circumstances,

consider ing your workload, the typ e of weather information, and any other relevant factors.

For example, for urgent weather hazard s, providing your PIREP to the air traffic controller

via the radio would likely result in the most rapid local dissemination of the information.

Interested in more information?

The information in this safety alert was excerpted from the NTSB ’s SIR-17/02 , which can be

accessed from the NTSB ’s Safety Studies and Special Reports web page (available from

www.ntsb. gov). Information about the NTSB ’s June 2016 forum, “PIREPs: Pay it

Forward …Because Weather for One is Weather for None ,” can be found on the NTSB ’s Previous

Events web page (also available from www.ntsb.gov ).

The following FAA resources (available from www.faa.gov ) provide guidance on how to properly

report weather phenomena and their respective intensity classifications :

• The Aeronautical Information Manual section 7 -1-19, “PIREPs, ” provides information on how

to report icing, turbulence, visibility restrictions, and other hazards .

• Advisory Ci rcular 00-45H, “Aviation Weather Services ,” contains information on how to

report and read PIREPs, apply intensity modifiers for precipitation and other weather

phenomena, and use the remarks section to further describe the weather phenomena .

The FAA Safety Team (FAASTeam) provides access to (and, through the WINGS —Pilot Proficiency

Program , credits for ) the online , interactive course ALC -96, “SkySpotter: PIREPs Made Easy ,”

which was developed by the Aircraft Owners and Pilots As sociation (AOPA) Air Safety Institute. The

course explains the importance of PIREPs , provides guidance on how to submit them , and includes

guidance on assess ing cloud cover elements and classify ing other weather phenomena . (In

April 2017, in response to NTSB Safety Recommendation A -17-14, the AOPA Air Safety Institute

stated that it plans to update this course .) This course and others can be accessed from the

FAASTeam website (www.faasafety.gov ). Course access requires login through a free FAASTeam

account.

Electronic PIREP submission information can be found from the following sources :

• The flight service provider Leidos (formerly known as Lockheed Martin Flight Services)

support s the electronic submission of PIREPs from some aircraft equipment and web-based

flight -planning applications. More information about electronic PIREP submission can be

found from the Flight Service website (www.1800wxbrief.com ).

• The Aviation Weather Center (AWC) enables pilots and dispatchers to register for a PIREP

submission account to file PIREPs online using its web -based submission tool. Registration

instructions can be accessed from the AWC ’s website (www.aviationweather.gov ) under the

“User ” menu and “Regis ter” option . PIREPs submitted via the web -based tool are displayed

immediately on the AWC ADDS (Aviation Digital Data Services) web page

(www.aviatio nweather.gov/airep ) in graphical and text formats.

The NTSB ’s Aviation Information Resources web page, www.ntsb.gov/air , provides convenient

access to NTSB aviation safety products . This safety alert and others can be accessed from the

Aviation Safety Alerts link.