British Airways Flight 38
British Airways Flight 38 was a scheduled flight of the British airline British Airways from Beijing airport to London Heathrow airport, touched down on 17 January 2008 during landing at 12:42 local time clock of the runway. These were around the first accident of a Boeing 777 that had to be discarded as a result of the incident. In the crash-landed twelve people were injured.
The course of the accident
The Boeing 777- 236ER with the registration G - YMMM and serial number 30314 responded shortly before landing at an altitude of 720 feet approximately 3200 m from the touchdown point not on an Auto Throttle request still on a manual thrust level of the pilot. The autopilot of the aircraft tried as intended by the instrument landing system glide path observed and reduced at an altitude of 200 feet, the speed to 108 knots. In an altitude of 175 feet, the autopilot released the aircraft to manual approach. The aircraft touched down so about 300 meters before the runway 27L, and slid over the grass. Here, the front landing gear buckled and the right main landing gear broke up the hull and penetrated into the central fuel tank and fuselage. The left main landing gear was pushed up through the wing through. The machine was then at the beginning of the runway to a stop. Although fuel ran out, there was no fire. Passengers reported that the aircraft " just plummeted " after the landing gear was engaged. The aircraft flew over the A30 only about 8 m above including moving cars, including the car of Prime Minister Gordon Brown, who was of an impending trip abroad on the way to the airport. Eight ambulances were sent to the accident site. Four crew members and eight passengers received minor injuries in the crash landing. Some of them have been associated with grazes in hospitals, but was released in the evening. A passenger was retained with a gash in the hospital overnight.
The 138 -ton aircraft was severely damaged. It was, it was the first total loss of a Boeing 777 However, it was the third incident in which a Boeing 777 of British Airways was involved.
Possible cause of the accident
The UK authority for aviation accidents, the Air Accident Investigation Branch ( AAIB ) is investigating the aviation accident. In line with the international practice, have the manufacturer of the engines, Rolls -Royce, Boeing and - since it is a product made in the United States aircraft - the National Transportation Safety Board ( NTSB ) provided assistance with the investigation.
The captain Peter Burkill sparked only a few seconds before the impact an emergency call to the control tower, previously there were no signs of distress of the aircraft. David Learmount, an analyst for Flight International, noted that " had aircraft either a complete or severe loss of drive and that this was very late when landing because the pilot did not have time to say this is the air traffic control or the passengers ." It has been speculated that due to the weather conditions shearing winds were the cause of the sinking of the machine. The METAR in force at the time of the accident predicted ICAO provisions in accordance with possible gusts; but there were registered at the time of the accident, neither Gust nor wind shear.
The captain Peter Burkill told a press conference that he would not comment during the ongoing investigation of the AAIB publicly about the incident. He said, however, that the first officer John Coward piloted the aircraft during the landing approach.
A preliminary report of the AAIB noted that in the plane at an altitude of about 600 feet ( about 200 m ) above the ground and about two nautical miles ( about 3.7 miles) away from the touchdown was a shear failure occurred and consequently to was quickly dropped. It then touched the ground about 300 meters before the start of the fixed runway. The impact occurred in the vicinity of the breakpoint NB1, which leads from the runway to the taxiway N 27L.
The initial theories about the cause have included different areas. Because both engines of a thrust requirement is not obeyed, a mechanical engine failure is not considered as a cause, as the simultaneous failure of two engines is not very likely.
The possibility of a bird strike was considered. There were at the time of the accident, however, no corresponding thereto observations. The assumption that the average tank could have been frozen, prompting some airlines United Airlines and American Airlines to measures that should ensure the quality of the fuel used.
A month after the incident gave the investigating authorities announced that there was " no evidence of a mechanical failure, bird strike or icing " and that "there is no evidence of fuel contamination or unusually high content of water in it " and that "there are no abnormalities in the major systems of the aircraft " was. The report, however, pointed to cavitation in two high-pressure fuel pumps, indicating a limitation of the fuel supply, even though the manufacturer stated that both pumps were able to afford the full fuel flow. The report stated that the aircraft had flown on his journey through extremely cold air masses, temperatures, however, these were not low enough to freeze the fuel.
Accordingly, the speculation on the electronics and fuel supply are concentrated. The failure of the software or electronics, through which the engines are controlled, is a widespread theory. The daily The Guardian quoted an anonymous source on January 19, after a Engine Pressure Ratio Meter had failed and that an automatic alert the pilots had not come across this problem.
A fault in the electronic system of the aircraft could have led to a disruption of the connection between the control by the automatic and manual control elements, and the two engines. It has also been speculated that interference could have led by the anti- terrorist system of the motorcade of Prime Minister to the failure. These two theories have been excluded by the Bulletin of the investigating authorities on 12 May, however.
The Bulletin of the AAIB on 12 May also ruled out wind shear as a cause for the crash landing. The investigations are now focusing on the cause of cavitation at the high pressure pumps of both engines, which point to an exceptionally low pressure at the supply line.
The preliminary investigation report by the UK Air Accidents Investigation Branch are final at the most likely cause is that ice in the fuel system that supplies the engine with fuel, was responsible for the accident. A study published by the NTSB on 11 March 2009 safety recommendation that has this incident and another engine - power loss of a 777- 200ER of Delta Airlines on 26 November 2008 the subject, considered possible Eisanlagerungen in the fuel / oil heat exchangers Fuel / Oil heat Exchangers ( FOHE ) Trent 800 engines as critical, since the fuel quantity is not sufficient due to the fuel side of the heat exchanger clogging with ice crystals for requested by the pilot thrust.
Disruption of flight operations
Outgoing flights were delayed. Because the fire brigades were in use by the accident, there was not a sufficient safeguard for the rest of the airport. Therefore, the flight operations at the airport was briefly stopped completely. All short-haul flights and some flights on long-haul flights were canceled for the rest of the day. Otherwise, there were delays of up to 1 ½ hours because the start and runway 27L initially remained closed. Twenty-four incoming flights were diverted to Gatwick, Luton or Stansted. By the evening of January 17 221 flights were canceled. The Department of Transportation issued an exception to the ban on night flights.
Also on January 18, yet it came to deletions of 113 short-haul flights because crews and aircraft were not located in the planned locations. The wreckage of the plane was lifted on 20 January by two mobile cranes and loaded onto a low loader to be transported can.
Similar incidents
On 27 February 2008, a pilot of a Boeing 777-300 of Singapore Airlines noticed two strokes in the engines. The warning message " Engine Turbine Overspeed " appeared on the instrument panel. The aircraft then landed without problems at the airport Domodedovo.
A day later, the left engine of a Boeing 777-200 of American Airlines did not respond to the thrust level of the pilot. It took about 10 to 15 seconds for the engine acceleration.