 Wreckage of the Air India Boeing 787-8 Dreamliner plane sits on the open ground. (Photo: REUTERS/Amit Dave) |
The Boeing 787 Dreamliner bound for London from the Indian city of Ahmedabad began to lose thrust and sink shortly after takeoff, according to the report on the world's deadliest aviation accident in a decade released on Saturday by Indian accident investigators.
The report by India's Aircraft Accident Investigation Bureau (AAIB) about the June 12 crash raises fresh questions over the position of the critical engine fuel cutoff switches.
Almost immediately after the plane lifted off the ground, closed-circuit TV footage showed a backup energy source called a ram air turbine had deployed, indicating a loss of power from the engines.
In the flight's final moments, one pilot was heard on the cockpit voice recorder asking the other why he cut off the fuel. "The other pilot responded that he did not do so," the report said.
It did not identify which remarks were made by the flight's captain and which by the first officer, nor which pilot transmitted "Mayday, Mayday, Mayday" just before the crash.
Air India acknowledged the report in a statement. The carrier said it was cooperating with Indian authorities but declined further comment.
Experts have said a pilot would not be able to accidentally move the fuel switches.
"If they were moved because of a pilot, why?" asked US aviation safety expert Anthony Brickhouse.
The switches flipped a second apart, the report said, roughly the time it would take to shift one and then the other, according to US aviation expert John Nance. He added that a pilot would normally never turn the switches off in flight, especially as the plane is starting to climb.
Flipping to cutoff almost immediately cuts the engines. It is most often used to turn engines off once a plane has arrived at its airport gate and in certain emergency situations, such as an engine fire. The report does not indicate there was any emergency requiring an engine cutoff.