Contaminated Fuel Could Be Factor In January 17 Landing Accident

British Air Accident Investigation Branch inspectors continue to study the fuel system of the British Airways Boeing 777-200ER that crash-landed last week at Heathrow Airport in London. While the exact cause of the January 17 accident has not yet been established, investigators are looking closely at the possibility of a fuel flow interruption or fuel contamination, reports The Seattle Times.

As ANN reported last week, the AAIB -- which initially indicated the 777’s Rolls Royce Trent 895 had failed to respond to the auto-throttle command -- now says both engines spooled up when commanded, but thrust levels soon reduced. The number two (right) engine reduced thrust after about three seconds, while the number one (left) engine reduced after about eight seconds.

This appears to be consistent with post-crash photos, which show considerable fan damage to number one, while number two is relatively intact. Investigators say both engines continued to produce thrust at an engine speed above flight idle, but far less than commanded thrust.

The 777, with 136 passengers and 16 crew, lost power about two miles from touchdown at a height of 600 feet.

Investigators say "All possible scenarios that could explain the thrust reduction and continued lack of response to throttle-lever inputs are being examined," and add that flight data recorder information indicates normal performance from both engine control commands and the auto-throttle.

The accident resulted in few injuries, mostly from exiting the aircraft. The co-pilot has been highly praised for his skill in clearing the houses near the end of the runway and putting the aircraft into the grass.

Also, good news for passengers and investigators alike: the jet survived largely intact, a significant help in determining the cause of the accident.

After fueling in Beijing, the aircraft flew nonstop to London, arriving with "adequate" fuel on board according to officials. The flight apparently encountered extremely cold temperatures of -60 to -75 degrees Celsius while flying over Russia and northern Europe. Such low temperatures are normally not a problem with jet fuel, but could adversely affect potentially contaminated fuel.

The accident was the first crash of a 777 in more than a dozen years of flying extremely long-haul routes all over the world.

The investigation continues, and ANN will bring you updates as they become available.

FMI: www.aaib.dft.gov.uk/home/index.cfm