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.
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.
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.
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.
TAMDAR is a weather monitoring system that consists of an in situ atmospheric sensor mounted on commercial aircraft for data gathering. It collects information similar to that collected by radiosondes carried aloft by weather balloons. It was developed by AirDat LLC, which was acquired by Panasonic Avionics Corporation in April 2013 and was operated until October 2018 under the name Panasonic Weather Solutions. It is now owned by FLYHT Aerospace Solutions Ltd.
The 1971 January 22 Surgut Aeroflot Antonov An-12 crash occurred on 22 January 1971, when an Aeroflot Antonov An-12B, registered CCCP-11000, flying from Omsk Tsentralny Airport, in the Soviet Union's (RSFSR), 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, 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.
Aeroflot Flight 141 was an international flight from Moscow to Prague. On 19 February 1973, the Tupolev Tu-154 crashed 1.5 kilometres short of runway 25 of Prague Ruzyně Airport. Most of the passengers survived the crash, but many died in the fire that followed. Out of the 87 passengers and 13 crew members, 62 passengers and 4 crew members perished with 18 occupants having serious injuries and the remaining 16 with either minor or no injuries. The crash was the first loss of and first fatal accident involving the Tu-154.
Bhoja Air Flight 213 was a domestic scheduled passenger flight operated by Pakistani airline Bhoja Air from Karachi to Islamabad. On 20 April 2012, the Boeing 737-236A aircraft serving the route crashed in bad weather during its final approach to land. All 121 passengers and 6 crew members aboard were killed. With 127 deaths, it remains as the second deadliest air disaster in Pakistan.
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 1971 January 31 Surgut Aeroflot Antonov An-12 crash occurred on 31 January 1971, 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), 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.
Numerous 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 60 passengers and 6 crew members on board 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.
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.
