Friday, January 18, 2008

UK's AAIB: Initial report on British Airways accident at Heathrow

AAIB logoThe United Kingdom's Air Accidents Investigation Branch (AAIB) issued its initial report regarding yesterday's crash landing of a British Airways Boeing  777 at London's Heathrow International Airport (LHR). The B777-236ER aircraft (registration number G-YMMM), operating as British Airways Flight BA 038 from Beijing to London, landed short on runway 27L at LHR. All 136 passengers and 16 crew on board survived. The aircraft was substantially damaged.

The AAIB investigation is ongoing, however today's report describes the event, and reports the agency's preliminary findings based on the initial examination of the Flight Data Recorder, and interviews with the crew and others at the accident scene.

Here are some excerpts from the report, which describe the event (re-paragraphed for easier reading):
Following an uneventful flight from Beijing, China, the aircraft was established on an ILS approach to Runway 27L at London Heathrow.

Initially the approach progressed normally, with the Autopilot and Autothrottle engaged, until the aircraft was at a height of approximately 600 ft and 2 miles from touch down. The aircraft then descended rapidly and struck the ground, some 1,000 ft short of the paved runway surface, just inside the airfield boundary fence. The aircraft stopped on the very beginning of the paved surface of Runway 27L.

During the short ground roll the right main landing gear separated from the wing and the left main landing gear was pushed up through the wing root. A significant amount of fuel leaked from the aircraft but there was no fire.

An emergency evacuation via the slides was supervised by the cabin crew and all occupants left the aircraft, some receiving minor injuries.


The flight crew were interviewed on the evening of the event by an AAIB Operations Inspector and the Flight Data Recorder (FDR), Cockpit Voice Recorder (CVR) and Quick Access Recorder (QAR) were removed for replay.

The CVR and FDR have been successfully downloaded at the AAIB laboratories at Farnborough and both records cover the critical final stages of the flight. The QAR was downloaded with the assistance of British Airways and the equipment manufacturer. All of the downloaded information is now the subject of detailed analysis.

Examination of the aircraft systems and engines is ongoing.

Initial indications from the interviews and Flight Recorder analyses show the flight and approach to have progressed normally until the aircraft was established on late finals for Runway 27L.

At approximately 600 ft and 2 miles from touch down, the Autothrottle demanded an increase in thrust from the two engines but the engines did not respond. Following further demands for increased thrust from the Autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond.

The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface. [AAIB Ref: EW/C2008/01/01]
The AAIB states that the accident investigation will continue, focusing on "more detailed analysis of the Flight Recorder information, collecting further recorded information from various system modules and examining the range of aircraft systems that could influence engine operation."

UPDATE January 24, 2008: The UK's AAIB has issued an update to its preliminary report on the British Airways accident. Excerpt:
Recorded data indicates that an adequate fuel quantity was on board the aircraft and that the autothrottle and engine control commands were performing as expected prior to, and after, the reduction in thrust.

All possible scenarios that could explain the thrust reduction and continued lack of response of the engines to throttle lever inputs are being examined, in close cooperation with Boeing, Rolls Royce and British Airways. This work includes a detailed analysis and examination of the complete fuel flow path from the aircraft tanks to the engine fuel nozzles.
Click here to read the update on the AAIB website.

NOTE:  Click here to view all posts on Aircrew Buzz about British Airways Flt 038.