A pilot report or PIREP is a report of actual flight or ground conditions encountered by an aircraft. Reports commonly include information about atmospheric conditions (like temperature, icing, turbulence) or airport conditions (like runway condition codes or ground equipment failures). This information is usually relayed by radio to the nearest ground station, but other options (e.g. electronic submission) also exist in some regions. [1] The message would then be encoded and relayed to other weather offices and air traffic service units.
Although the actual form used to record the PIREP may differ from one country to another, the standards and criteria will remain almost the same. At a minimum the PIREP must contain a header, aircraft location, time, flight level, aircraft type and one other field.
In recent years[ when? ], a PIREP will also include UA or UUA used to identify the PIREP as routine or urgent.
Like PIREPs, Aircraft Reports (AIREP) are reports of actual weather conditions of an aircraft in flight. AIREPs are often automated reports, contrary to PIREPs. Likewise, a different encoding is used for either type.
The message identifier "UA" is used when the PIREP contains non-hazardous weather information. If the PIREP contains a report of a tornado, funnel cloud, waterspout, severe turbulence, severe icing, hail, or a low-level wind shear hazard, the identifier "UUA" would be used.
The location (/OV) can be reported in one of three ways: as a direction and distance from a navigation aid (NAVAID), as a direction and distance from an airport, or as the latitude and longitude of the aircraft.
The time (/TM) used is the UTC time that the PIREP is reported.
The flight level (/FL) is reported as either a three digit value that indicates the altitude of the aircraft above sea level in hundreds of feet or can be one of three abbreviations: DURD (during descent or on approach), DURC (during climb or after takeoff) and UNKN (unknown).
Aircraft type (/TP) will be the approved ICAO designator, or UNKN if not reported.
Sky cover (/SK) is used to report the cloud layer amounts and the height of the cloud base. The tops of the cloud layers can also be included, as can more than one layer of cloud. Heights are in hundreds of feet above sea level and are three digits. Abbreviations used in this group are "CLR" (clear), "FEW" (few), "SCT" (scattered), "BKN" (broken) and "OVC" (overcast). [2]
Temperature (/TA) is the air temperature in whole degrees Celsius as a two-digit value, with negative temperatures preceded by a minus (-) sign. In the United States, negative temperatures are preceded by the letter M (M). [3] [4]
Wind velocity (/WV) must contain both the wind speed and direction. Direction is reported as a three-digit value in whole degrees true and the wind speed in knots also in three digits.
Turbulence (/TB) and the intensity are reported in a PIREP based on the aircraft and occupants reaction to the turbulence. The altitude of the turbulence should be included using three-digit groups. When the top or the base of the turbulence is unknown then the abbreviation BLO (below) or ABV (above) should be used. Turbulence should be reported as LGT (light), MDT (moderate), SVR (severe) or in exceptional cases EXTRM (extreme). Clear-air turbulence is reported as CAT.
Icing (/IC) is reported by type and the intensity or rate of accretion. The type of ice is reported as "CLR" (clear), "RIME", or "MXD" (mixed). The intensity is reported as "TR" (trace), "LGT" (light), "MDT" (moderate), and "SVR" (severe). (Units are measured in MSL - MEAN SEA LEVEL)
Remarks (/RM) report on other weather conditions that are not covered in the rest of the PIREP may include such things as icing in precipitation, thunderstorms, St. Elmo's fire and frontal conditions. There are many other types of weather conditions that could be reported in a PIREP.
The above explanation of PIREP fields is Canadian. The United States version may also include a weather (/WX) group, while other countries may use other groups and measurements.
These examples are taken from the Canadian MANOBS (Manual of Surface Weather Observations) published by Environment Canada.[ citation needed ]
In the US, air traffic controllers are required to solicit PIREPs upon request of other facilities or pilots, or when any of the following conditions exists or is forecast in their area. [4]
At least once hourly, terminal controllers must obtain a descent/climb-out PIREP, including cloud information and other related phenomena.
A weather map, also known as synoptic weather chart, displays various meteorological features across a particular area at a particular point in time and has various symbols which all have specific meanings. Such maps have been in use since the mid-19th century and are used for research and weather forecasting purposes. Maps using isotherms show temperature gradients, which can help locate weather fronts. Isotach maps, analyzing lines of equal wind speed, on a constant pressure surface of 300 or 250 hPa show where the jet stream is located. Use of constant pressure charts at the 700 and 500 hPa level can indicate tropical cyclone motion. Two-dimensional streamlines based on wind speeds at various levels show areas of convergence and divergence in the wind field, which are helpful in determining the location of features within the wind pattern. A popular type of surface weather map is the surface weather analysis, which plots isobars to depict areas of high pressure and low pressure. Cloud codes are translated into symbols and plotted on these maps along with other meteorological data that are included in synoptic reports sent by professionally trained observers.
METAR is a format for reporting weather information. A METAR weather report is predominantly used by aircraft pilots, and by meteorologists, who use aggregated METAR information to assist in weather forecasting. Today, according to the advancement of technology in civil aviation, the METAR is sent as IWXXM model.
In aeronautics, a descent is any time period during air travel where an aircraft decreases altitude, and is the opposite of an ascent or climb.
In meteorology, clear-air turbulence (CAT) is the turbulent movement of air masses in the absence of any visual clues such as clouds, and is caused when bodies of air moving at widely different speeds meet.
SIGMET, or Significant Meteorological Information, is a severe weather advisory that contains meteorological information concerning the safety of all aircraft. Compared to AIRMETs, SIGMETs cover more severe weather. Today, according to the advancement of technology in civil aviation, the SIGMET is sent as IWXXM model.
An AIRMET, or Airmen's Meteorological Information, is a concise description of weather phenomena that are occurring or may occur (forecast) along an air route that may affect aircraft safety. Compared to SIGMETs, AIRMETs cover less severe weather: moderate turbulence and icing, sustained surface winds of 30 knots or more, or widespread restricted visibility. Today, according to the advancement of technology in civil aviation, the AIRMET is sent as IWXXM model.
American Eagle Flight 4184, officially operating as Simmons Airlines Flight 4184, was a scheduled domestic passenger flight from Indianapolis, Indiana, to Chicago, Illinois, United States. On October 31, 1994, the ATR 72 performing this route flew into severe icing conditions, lost control and crashed into a field. All 68 people aboard were killed in the high-speed impact.
American Airlines Flight 1572 was a flight from Chicago O'Hare International Airport to Bradley International Airport on November 12, 1995. The McDonnell Douglas MD-83 struck trees and an instrument landing system (ILS) antenna during landing, causing $9 million in damage to the aircraft.
Airport weather stations are automated sensor suites which are designed to serve aviation and meteorological operations, weather forecasting and climatology. Automated airport weather stations have become part of the backbone of weather observing in the United States and Canada and are becoming increasingly more prevalent worldwide due to their efficiency and cost-savings.
The 22 January 1971 Surgut Aeroflot Antonov An-12 crash occurred when an Aeroflot Antonov An-12B, registered CCCP-11000, flying from Omsk Tsentralny Airport, in the Soviet Union's (RSFSR) on 22 January 1971, crashed 15 km (9.3 mi) short of the runway on approach to Surgut International Airport, Surgut, RSFSR. An investigation found the aircraft's ice protection system was ineffective because the engine bleed air valves were closed during the flight; ice therefore built up on the aircraft causing it to go out of control.
Iran Air Flight 277 was a scheduled Iran Air flight from Mehrabad International Airport, Tehran to Urmia Airport, Iran. On January 9, 2011, the Boeing 727 serving the flight crashed after an aborted approach to Urmia Airport in poor weather. Of the 105 people on board, 78 were killed. The official investigation concluded that icing conditions and incorrect engine management by the crew led to a double engine flame-out, loss of altitude and impact with the ground.
Pan Am Flight 923 was a Douglas DC-4 operating from Seattle, Washington to Juneau, Alaska, which crashed into Tamgas Mountain on Annette Island, Alaska, on October 26, 1947. All 18 passengers and crew on board were killed.
The 31 January 1971 Surgut Aeroflot Antonov An-12 crash occurred when an Aeroflot Antonov An-12B, aircraft registration CCCP-12996, flying from Roshchino International Airport, Tyumen, in the Soviet Union's Russian Soviet Federated Socialist Republic (RSFSR) on 31 January 1971, crashed 13.6 km (8.5 mi) short of the runway on approach to Surgut International Airport, Surgut, RSFSR. An investigation found the aircraft's loss of control was caused by icing.
Loganair Flight 670A (LC670A) was a scheduled cargo flight for the Royal Mail from Edinburgh-Turnhouse Airport, Scotland to Belfast International Airport. On 27 February 2001 the Short 360 operating the flight ditched in the Firth of Forth off Edinburgh at around 17:30 local time; the two crewmembers' bodies were found in the wreckage a few hours after the crash.
Numerous aviation accidents have occurred in the vicinity of thunderstorms due to the density of clouds. It is often said that the turbulence can be extreme enough inside a cumulonimbus to tear an aircraft into pieces, and even strong enough to hold a skydiver. However, this kind of accident is relatively rare. Moreover, the turbulence under a thunderstorm can be non-existent and is usually no more than moderate. Most thunderstorm-related crashes occur due to a stall close to the ground when the pilot gets caught by surprise by a thunderstorm-induced wind shift. Moreover, aircraft damage caused by thunderstorms is rarely in the form of structural failure due to turbulence but is typically less severe and the consequence of secondary effects of thunderstorms.
The 2000 Marsa Brega Short 360 crash occurred on 13 January 2000 when a Swiss-registered Short 360 leased by Avisto ditched into the sea near Marsa Brega in Libya. The aircraft was chartered by Sirte Oil Company to transport oil workers to the city. It was carrying 41 people. Most of the passengers were foreigners. As both engines failed in mid-flight, the crew chose to ditch the aircraft. A total of 21 people died in the crash.
Iran Aseman Airlines Flight 3704 was a scheduled Iranian domestic passenger flight from Iranian capital Tehran Mehrabad International Airport to Yasuj in southwest Iran. On 18 February 2018, during its approach to Yasuj, the aircraft serving the flight, an ATR 72-212 operated by Iran Aseman Airlines, crashed into Mount Dena in the Zagros Mountains near Noqol village in Semirom county, Isfahan Province. All 66 people on board, including 60 passengers and 6 crew members, were killed.
Aeroflot Flight 315 was a regularly scheduled passenger flight operated by Aeroflot from Vnukovo International Airport in Moscow to Lviv Airport in Lviv, Ukraine. On 16 November 1959, the Antonov An-10 operating this flight crashed short of the airport runway while on final approach. All 32 passengers and eight crew members were killed.
Aeroflot Flight N-36 was a scheduled domestic Aeroflot passenger flight from Chernivtsi International Airport to Kiev Zhuliany Airport, Ukrainian Soviet Socialist Republic that crashed on 17 December 1976 near Kyiv airport, resulting in 48 fatalities and 7 survivors.
Ryan International Airlines Flight 590 was a cargo flight carrying mail for the United States Postal Service from Greater Buffalo International Airport (BUF) in Buffalo, New York, to Indianapolis International Airport (IND) in Indiana, with a stopover at Cleveland Hopkins International Airport (CLE) in Cleveland, Ohio. On February 17, 1991, the McDonnell Douglas DC-9-15RC operating the flight crashed on takeoff from Cleveland during icing conditions. Both pilots, the aircraft's only occupants, were killed. The National Transportation Safety Board (NTSB) determined that the causes of the crash were the flight crew failing to deice their aircraft, and the inexperience of the Federal Aviation Administration (FAA), McDonnell Douglas, and Ryan International Airlines with icing condition on DC-9-10 aircraft.