AircraftNews.Com

Federal regulators propose requiring modifications to engines of Boeing 777s powerd by the RR Trent engine to prevent ice from forming in fuel lines on long flights, a problem blamed for the British Airways crash last year.

The work would have to be completed by January 2011.

The Federal Aviation Administration (FAA) proposed the safety directive after a similar move by European regulators called for redesigning a heat exchanger in the RR Trent engines in which engine oil is cooled and fuel heated.

About 50 such planes operate in the United States.

In January 2008, a British Airways jet crashed short of the runway at London’s Heathrow after both engines lost power. No one was killed, but several passengers were hurt. The pwer loss was initially mysterious but careful investigation revealed evidence of cavitation damage in the engine fuel pumps whic was finally traced to ice formation after unusualy prolonged very low temperatures in the cruise segment of flight.

It was thought that ice built up during the flight over a polar route. They said that when the pilots applied thrust for landing, the ice dislodged and blocked the flow of fuel.

Ice buildup was also suspected in a Delta jet that lost power in one engine on a trip from Shanghai to Atlanta last November. The plane made a normal landing.

Boeing and Rolls-Royce have been working with the FAA and European aviation regulators to certify a redesigned heat exchanger with greater ability to handle ice.

The order would cover all American Airlines’ 47 Boeing 777s. Delta has eight 777s with Trent engines.

The work on each plane would have to be completed before the jet flies another 6,000 hours after the rule takes effect, but no later than Jan. 1, 2011.

Boeing 777s poweredwould be affected as many have engines made by General Electric and Pratt & Whitney.