TransAsia Airways Flight 791
| TransAsia Airways Flight 791 | |
|---|---|
.jpg) An identical ATR 72-201 from TransAsia Airways |
|
| Accident summary | |
| Accident type | Loss of control due to icing |
| place |
Formosa Strait , 17 km southwest of Magong , Penghu Islands , Taiwan
|
| date | December 21, 2002 |
| Fatalities | 2 |
| Survivors | 0 |
| Aircraft | |
| Aircraft type |
  ATR 72-202
|
| operator |
TransAsia Airways
|
| Mark |
B-22708
|
| Departure airport |
Taiwan Chiang Kai Shek Airport , Taiwan
|
| Destination airport |
Macau Airport , Macau
|
| crew | 2 |
| Lists of aviation accidents | |
TransAsia Airways Flight 791 ( flight number GE791 ) was an international cargo flight of the Taiwanese airline TransAsia Airways from Airport Taipei Chiang Kai-shek to Macau Airport . On December 21, 2002 there was an accident on this flight after the wings of the ATR 72-202 had iced up during flight, which resulted in a stall . The machine subsequently crashed into Formosa Strait , killing both crew members on board.
plane
The aircraft concerned was ATR 72-202, a model of the Italian-French consortium Avions de Transport Régional (ATR) founded by Aeritalia and Aérospatiale for the construction of regional aircraft . The machine was 10 years and 3 months old at the time of the accident. It had the model serial number 322, had been fully assembled at the ATR production site in Toulouse and made its maiden flight on August 29, 1992. The machine was delivered to TransAsia Airways on September 28 of the same year . The machine received the aircraft registration B-22708 . From October 12, 1998, the machine was leased to the British airline Gill Airways , where it was temporarily given the G-BXYV identifier . From February 1, 2002, the machine was back in service with TransAsia Airways, where it was now used as a cargo aircraft. At that time, unlike the airline's passenger aircraft, the machine was painted completely white and only had the company's lettering and the CARGO logo on the fuselage . The twin-engine regional airliner was with two turboprop engines of the type Pratt & Whitney Canada PW124B equipped.
crew
There was only a two-person crew, consisting of the master and first officer, on board. Both crew members were Taiwanese.
The 53-year-old captain was a former pilot in the Taiwanese Air Force and had piloted military cargo planes there. His flight experience from his military career was 3,638 flight hours. Since February 1991 he flew for TransAsia Airways. In May of the same year he received training to become a pilot for the ATR 42 and ATR 72 aircraft types . In September 1993 he was finally promoted to captain of these types of aircraft. His total flight experience at the time of the accident was 14,247 flight hours, including 10,608 with ATR 42 and ATR 72 machines
The 34-year-old first officer was trained from June 1996 to July 1997 at Flight Safety International US to pilot the ATR 42 and ATR 72 aircraft. During this time he completed 307 flight hours with these two types of aircraft. He joined TransAsia Airways in September 1997, where he received training to pilot ATR aircraft until November 27 of the same year. In July 1998 he finally completed the necessary training courses to be admitted to the position of first officer. At the time of the accident, he had 4578 hours of flight experience.
Flight history
On that day, an overnight cargo flight from Taipei to Macau was to be operated by plane . The cargo consisted of textiles, leather and electronic components. The machine started at 01:05 a.m. local time.
the accident
.jpg)
At 01:51 a.m., the crew reported to air traffic control in Taipei and asked for clearance to descend from 18,000 to 16,000 feet (5486/4877 meters). To 01:52:10 pm, the activated stall warning (5442 meters) at a height of 17,853 feet by the warning horn sounded, shaking the control column. The pilots deactivated the autopilot and tried to get the machine under control manually. The machine got into a dive and lost within 16 seconds 14,456 feet (4406 meters) in height. This corresponds to an average speed of 991 km / h during the dive, almost twice the top speed of an ATR 72-200. At 01:52:47, the machine was at an altitude of 3,027 feet (923 meters). The cockpit voice recorder stopped recording three seconds later . The machine crashed into the sea 17 kilometers southwest of Magong .
root cause
During the aircraft accident investigation it was found that the machine had flown through an area in which there was severe icing in flight, which had led to a stall . The pilots had not been adequately trained by the airline to recognize and assess atmospheric icing conditions. This meant that they did not respond adequately to the dangerous situation. After the pilots became aware of the icing conditions, the de-icing system was activated twice, but the pilots did not then familiarize themselves with the manual which laid down the procedure in such cases. Here the manual stipulated that you should watch out for significant icing. The unexpected drop in speed, which was shown by the speedometer, was an indication of such considerable icing. The flight crew did not respond to the icing conditions with the necessary vigilance and awareness that the aircraft might be exposed to extreme conditions that could seriously affect its performance and controllability. The crew's reaction to the perceived icing conditions was too slow, they did not react with an immediate reduction in altitude and did not take any other precautions in accordance with the safety regulations.
Before the stall occurred, unusual or uncontrolled roll and pitch movements were carried out with the machine. The control inputs after the stall and the attainment of an abnormal attitude did not comply with the operating regulations for intercepting aircraft from such attitudes. The aircraft's performance and controllability could have been significantly impaired due to the improper behavior of the pilots, which would have made it even more difficult to intercept the aircraft later. It cannot be confirmed whether a stable attitude could have been restored if the behavior of the crew had followed the relevant procedures and techniques.
During the flight there was ice formation on the wings, which significantly impaired the aerodynamics of the machine. The degree of aerodynamic impairment was 40 percent before the autopilot was switched off.
ATR machines are susceptible to icing
At the time of the accident it was well known that ATR 42 and ATR 72 machines are particularly susceptible to icing in flight. After the crash of an ATR 72 on American Eagle flight 4184 , the Federal Aviation Administration and NASA had extensively tested the ATR 72, whereupon the manufacturer changed the design of its machines, but above all the information in the logbooks, so that operators and Aircraft crews can respond adequately to such cases.
See also
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- Aircraft accident report in the Aviation Safety Network
- Transasia Airways - ATR - ATR72-200 (B-22708) flight GE791 on aviation-accidents.net
- GE 791 Ocurrence Investigation Report , Aviation Safety Council , Taipei, Taiwan
Coordinates: 23 ° 28 ′ 38.2 " N , 119 ° 25 ′ 45.6" E