As some of the visitors of this site commented in my previous posts dealing with the BA038 crash landing, it was at least strange that no new details dealing with the AAIB investigations had been surfacing. There is a lot of interest around this accident, many theories have been described in this site and around the Internet and, above all, we were expecting a final report in a relatively short time (30 days).
On May 12, the AAIB finally published a new Special Bulletin at the following page: http://www.aaib.dft.gov.uk/cms_resources/S3-2008%20G-YMMM.pdf
I read it carefully, eager to find some answers to the many questions dealing with the final flight of the British Airways B777 G-YMMM.
Unfortunately, nothing really new can be found in the SB that, according to the introduction, was not published because a root cause of the crash landing was discovered, but “In view of the sustained interest within the aviation industry, and amongst the travelling public, it is considered appropriate to publish an update on the continuing investigation into the accident….”. Maybe someone has understood that the continuing silence could be considered suspect.
Summing up the contents of the Bulletin, the extensive examination and the in-depth analysis of the wreckage and the flight data recorder analysis revealed no evidence of:
– Engine control systems malfuncion
– Electromagnetic Interference
– Wake turbolence effect
– Birdstrike or FOD (Foreign Object Damage) due to injection of a foreign object in the engine
– Fuel shortage or contamination
– Fuel freezing: even if the aircraft flew through the Scandinavian and Urals area with temperatures below -76° C, the fuel samples taken after accident showed a fuel freezing temperature of the Jet A-1 of -57ºC and the minimum recorded fuel temperature was -34°C (well above the freezing point)
– Fuel boost pumps failure
The only known problem so far, deals with an unusual cavitation damage of both high pressure (HP) fuel pumps from the engines, The cavitation is consistent with low fuel pressure at the inlet, that might have resulted in a reduced fuel flow.
According to the SB (that did not lead to any operational change ) the investigation continues in order to understand the dynamics of the fuel as it flows from the tank to the engine and in order to identify any restriction in environmental conditions similar to those experienced by the BA038 during its flight from Beijing to London at altitudes around 40.000 ft.