Looks like the investigation is focusing on slush or ice in the fuel system as the root cause of the problem. Is there a redesign of the oil coolers in the near future?
The article follows....
Re-Evaluating Long, Cold Flights
Crash May Prompt
New Safety Rules
For Boeing's 777
By
ANDY PASZTOR
April 25, 2008; Page B2
Prompted by the crash landing of a
British Airways jetliner near London earlier this year, air-safety investigators are moving to recommend heightened cold-temperature safeguards for Boeing 777 aircraft flying long polar routes, according to people familiar with the details.
In a few weeks, these people said, investigators are likely to warn operators and pilots of
Boeing Co.'s long-haul 777 models to take extra precautions when monitoring fuel temperatures on a growing number of extended flights over the North Pole. If temperatures creep too low, pilots can descend to warmer air or speed up to increase the heat generated by air friction against the plane's skin.
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The News: Investigators are moving to recommend cold-temperature safeguards for Boeing 777s on polar routes.
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Background: Slush or ice build-up in a British Airways 777 fuel system may have led to a Jan. 17 accident at London's Heathrow Airport.
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Outlook: Operational warnings or recommendations could come in the weeks ahead.
"It's a possibility" that such operational warnings or recommendations will be issued within the next few weeks, said David King, chief investigator for Britain's Air Accidents Investigation Branch, or AAIB, which is in charge of the probe. In an interview Thursday, Mr. King said safety experts are "looking at a wide range of things" affecting fuel management and environmental conditions on polar flights.
Though some are arguing for design changes, a team of U.S. and British investigators hasn't reached a consensus on whether to recommend modifications to make the fuel systems on some Boeing 777s more resistant to unusually frigid conditions. Such a move could be seen as a public relations blow to Boeing and
Rolls-Royce PLC, which supplied the engines and related hardware on the accident aircraft.
A spokesman for Rolls-Royce, which has declined to comment on the accident or the status of the investigation, said Thursday that the company "remains committed to working with the AAIB and Boeing to establish the root cause of the event" and is cooperating with other participants. British Airways, Boeing, the Federal Aviation Administration and the U.S. National Transportation Safety Board all declined to comment.
Investigators suspect that the Jan. 17 accident at London's Heathrow Airport occurred because slush or ice built up in part of the fuel system of the British Airways 777 during a long polar flight from China in unusually cold outside temperatures. As the widebody jet descended toward London, remnants of icy particles likely clogged a portion of its fuel system, starving the Rolls-Royce engines and providing minimal power despite pilot commands for more thrust.
The plane slammed down 300 yards short of the runway. All 152 aboard survived. The probe has been closely watched partly because the root cause remains elusive and complex. The accident has garnered attention because it is believed to be the first such incident involving both of a plane's engines while maneuvering at such a low altitude in more than 14 million 777 flight-hours since 1995.
Some U.S. experts have advocated changing the design of the oil cooler used on some versions of the Boeing 777 powered by Rolls-Royce engines, arguing that that is where ice or slush may have blocked proper fuel flow. Taking the unusual step of disclosing details of a pending investigations, Mr. King said: "I don't believe there is anyone on my team that would argue for a redesign" of the oil cooler.
Investigators have ruled out engine or computer malfunctions, and pilot slip-ups, as well as systemic problems with fuel-tank design, fuel pumps or temperature sensors, according to people familiar with the details.
Write to Andy Pasztor at
[email protected]