Boeing 777s may land in trouble again; NTSB asks Rolls-Royce to re-design engine component

The agency that investigates air accidents in the United States has warned that there is “a high probability” of the fault which led to the crashlanding of two Boeing 777s in 2008 happening to other aircraft.

The United States National Transportation Safety Board (NTSB) issued an “urgent safety recommendation” the other day in which it said there was a “high probability of something similar happening” because of a faulty component of the Rolls-Royce engine.

The NTSB also asked engine manufacturer Rolls-Royce to redesign the part that was unsafe and told airlines to ensure that the redesigned engines are fitted to all those aircraft which now use the faulty engines.

In the first incident, a Boeing 777 aircraft of British Airways, on January 17, 2008, experienced what is called a “dual engine rollback,” or sudden loss of power, on final approach and crashed near the runway at London’s Heathrow Airport. In the incident, one passenger was seriously injured, 12 others suffered minor injuries, and the aircraft was damaged considerably.

A comparable incident took place on November 26, 2008, when a Boeing 777 plane of the United States-based Delta Airlines suffered a “single engine rollback” while it was on cruise flight over Montana en route from Shanghai to Atlanta. Fortunately, the affected Boeing 777 landed safely in Atlanta after the flight crew followed the Boeing Company’s “procedure to recover engine performance.”

Investigators found that, in both cases of engine malfunction, a build-up of ice (from water normally present in all jet fuel) on the fuel/oil heat exchanger reduced the flow of fuel to the engine, leading to the “uncommanded engine rollback.”

Following the two incidents, the Boeing Company published a set of guidelines for pilots to follow in the event of experiencing similar problems. However, the United States National Transportation Safety Board – the independent regulatory and investigating agency of the United States government that is responsible for investigating accidents in civil transportation – refused to accept the Boeing Company’s move on the ground that the aircraft maker’s new procedures did not remove the risk of an accident.
The “only acceptable solution,” the NTSB said, was for Rolls-Royce to design “a new, ice-resistant fuel/oil heat exchanger (FOHE).”

Rolls-Royce had, in February 2009, announced that the redesign of engines was in progress, but indicated that the new parts would not be ready for being installed on aircraft till early 2010. Until that time, Rolls-Royce said, pilots flying the Boeing 777 aircraft with the engines would have to depend on the Boeing Company’s procedures.