In the world of aviation weather abbreviations and acronyms, pilot reports of weather conditions are known as pireps. And they're important for anyone who takes to the sky, not just those who fly jets up high.
From the way television meteorologists promote their stations' Doppler radars, you might think such devices tell us anything that we might want to know about what the weather is doing. That is far from the case. For places between weather stations - which is a lot of territory - no weather device is as good as a pilot at observing the heights of the tops and bottoms of clouds, as well as the visibility, turbulence, or whether the clouds are depositing ice on aircraft.
In fact, a pilot 2,000 feet above an airport with the world's most elaborate weather observing tools knows more about turbulence and icing there than what's recorded by any of today's ground-based weather instruments.
This is one reason that weather forecasters want more reports from pilots. This data helps them to see how their predictions are working out and supplies data for the next round of forecasts.
When you call or visit an FAA Flight Service Station for a preflight weather briefing, the information you receive on current weather should include pilot reports for your route of flight. If the briefer doesn't mention pilot reports, you should ask: "Are there any pireps along my route?" Unfortunately, all too often today the answer is likely to be "no."
This is one of the reasons why the AOPA Air Safety Foundation worked with the National Weather Service to create the SkySpotter program to encourage pilots to provide more reports. This interactive online course ( www.aopa.org/asf/skyspotter ) takes you through the basics of pilot reports, including how to give them, and shows you some of the things to look for. As you go through the program you take brief quizzes, and if you score well enough, you earn a SkySpotter certificate.
For more detail on pilot reports, including how to read the text versions of them, you can also consult the booklet Aviation Weather Services, FAA Advisory Circular (AC) 00-45E. This booklet is a good resource for flight instructors to keep on hand to help them answer student questions.
The box on this page shows the elements of a pilot report. If you go to the SkySpotter Web page you'll find forms listing this information, which you can download and print out. Take some along on flights and fill in the blanks before radioing in a report. By the way, you don't need to fill in all of the blanks. A report with only one or two of the items can be valuable.
All pilots should know how to make pireps and should ask for reports during preflight briefings. You should also ask for updated weather reports, including those from pilots, during flights.
To pass along pilot reports as well as obtain updated weather information, you should call Flight Watch on the frequency of 122.0 MHz. Flight Watch is an FAA service mainly for the exchange of weather information. It's available from 6 a.m. to 10 p.m. local time for aircraft flying at altitudes from 5,000 to 17,500 feet. Other frequencies are set aside for higher-flying aircraft. (See "Aviation Speak: Flight Watch," November 2002 AOPA Flight Training.)
Let's hit some of the high points about radioing in a pilot report, using the list of pirep elements. The type of report, the first line, means whether it's a routine report, coded as a "UA," or an urgent report of really dangerous weather such as a tornado, coded as "UUA." Location is given in terms of the distance in nautical miles and direction from an airport or a VOR station. If you are navigating toward the airport or VOR, you need to remember to add or subtract 180 degrees to give your direction from the airport or VOR. You can also give the location as your route, such as "between Oshkosh and Milwaukee."
Time is always in Universal Coordinated Time (UTC), which is usually called Zulu time in aviation and meteorology. If you don't know the Zulu time, tell Flight Watch whether the conditions you are reporting are happening now, or some time in the past. If in the past, give the time in minutes since you encountered the conditions you are reporting.
Your altitude is to the nearest 100 feet, and it will be reported as a flight level. For instance, 5,500 feet will be coded as 055, which you read as 5,500 by adding two zeros. A jet flying at 37,000 feet will report "Flight Level 370."
The aircraft type is important to help other pilots figure out just how bad turbulence or icing is. Moderate turbulence in a Cessna 152 is a lot different meteorologically from moderate turbulence in a Boeing 747.
For the "sky cover" part of the report, you should report the altitude of the tops and bottoms of clouds, if you know them. Weather reports give how much of the sky is covered by clouds. If less than 2/8 of the sky is covered, it's clear; from 3/8 to 4/8 is scattered; from 5/8 to 7/8 is broken; and completely covered is overcast. Instead of trying to remember these divisions, you could report some- thing like "clouds cover half the sky."
An important point to remember: The altitudes of the tops and bottoms of clouds are always above mean sea level because pilots read their altimeters to get the height of clouds. But cloud heights reported by weather stations on the ground are the height of the clouds above the ground.
An example shows what this means and how it can be very important. A pilot takes off on an IFR flight and notes that the altimeter reads 1,300 feet when the airplane enters the bottoms of clouds that completely cover the sky over the airport. If the airport's elevation is 1,000 feet, this means the bottom of the clouds are only 300 feet above the ground, and an airport weather station would report the ceiling as 300 feet.
"Flight visibility and weather" is how far you can see and what the weather is doing, such as clear, or light rain.
The temperature, from your airplane's outside air thermometer, should be in degrees Celsius. If you can determine the direction and speed of the wind, maybe from your GPS navigation unit, it's good information to report because it fills in important data gaps for forecasters.
For turbulence, don't say something like, "Wow, it's really bumpy up here." Instead, you should try to use the definitions of light, moderate, severe, or extreme turbulence as defined by the FAA. You'll find these in the ASF SkySpotter program and in the Aviation Weather Services booklet. In a similar way, if you began to see ice form on your aircraft, you should use the definitions of trace, light, moderate, and severe.
If you are having doubts about the weather ahead, you can always ask a controller or Flight Watch whether any airplanes are ahead of you that can tell you what the weather is doing. If you are on an instrument flight rules (IFR) flight you should ask the controller you're talking with for permission to leave the frequency to call Flight Watch to give a report and check for new weather information.
You can also give a pilot report after landing by calling 800/WXBRIEF. In this case, be sure to note the time you saw the conditions you want to report and either give the briefer the Zulu time or how many minutes before your call you saw the conditions.
In general, you want to exchange pilot reports with Flight Watch while you are en route, not while you're in the terminal area. The exception is if you need to report any hazards of which other pilots should be immediately warned. Such "urgent" pilot reports are given for tornadoes, funnel clouds (a tornado that does not touch the ground), or waterspouts (a tornado over water); severe or extreme turbulence; severe icing, hail, volcanic ash, or low-level wind shear that causes airspeed fluctuations of 10 knots or more within 2,000 feet of the surface.
You should also immediately report any other condition that could be potentially hazardous, such as a large flock of birds near the airport.
Remember, you don't need to have bad-weather news to report to make a pirep important. Your report of clear skies and smooth air might be just what a flight instructor has been waiting to hear before sending a student off on a first cross-country solo flight, or what a forecaster needs to confirm that her reasoning about today's weather is on the right track.
Jack Williams is the weather editor of USAToday.com. An instrument-rated private pilot, he is the author of The USA Today Weather Book and co-author with Dr. Bob Sheets of Hurricane Watch: Forecasting the Deadliest Storms on Earth.
Elements Of A Pilot Report
Pirep Format
UUA/UA: Type of report
OV: Location
TM: Time
FL: Altitude/flight level
TP: Aircraft type
SK: Sky cover
WX: Flight visibility and weather
TA: Temperature
WV: Wind
TB: Turbulence
IC: Icing
RM: Remarks
Related Articles
