Fuel control switches for the engines of an Air India flight that crashed last month were moved from the “run” to the “cutoff” position moments before impact, starving both engines of fuel, a preliminary investigation report said early Saturday.
The report, issued by India’s Aircraft Accident Investigation Bureau, also indicated that both pilots were confused over the change to the switch setting, which caused a loss of engine thrust shortly after takeoff.
The Air India flight — a Boeing 787-8 Dreamliner — crashed on June 12 and killed at least 260 people, including 19 on the ground, in the northwestern city of Ahmedabad. Only one passenger survived the crash, which is one of India’s worst aviation disasters.
The plane was carrying 230 passengers — 169 Indians, 53 British, seven Portuguese and a Canadian — along with 12 crew members.
According to the report, the flight lasted around 30 seconds between takeoff and crash. It said that once the aircraft achieved its top recorded speed, “the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another" within a second. The report did not say how the switches could have flipped to the cutoff position during the flight.
The movement of the fuel control switches allows and cuts fuel flow to the plane’s engines.
The switches were flipped back into the run position, the report said, but the plane could not gain power quickly enough to stop its descent after the aircraft had begun to lose altitude.
The report stated: “One of the pilots transmitted ‘MAYDAY MAYDAY MAYDAY’.”
Aviation expert and former airline pilot Terry Tozer said the engine cutoff switches being switched to off only seconds after takeoff was “absolutely bizarre.”
“Unfortunately, the altitude was so low that the engines were only beginning to recover and they didn’t have enough time,” Tozer told Sky News.
The report also indicated confusion in the cockpit moments before the crash.
In the flight’s final moment, 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.
The preliminary report did not recommend any actions for Boeing, which said in a statement that it “stands ready to support the investigation led by India’s Aircraft Accident Investigation Bureau.”
“Our deepest condolences go out to the loved ones of the passengers and crew on board Air India Flight 171, as well as everyone affected in Ahmedabad,” the statement added.
India’s civil aviation minister, Kinjarapu Ram Mohan Naidu, said the report’s findings were preliminary and one should not “jump into any conclusions on this.”
“Let us wait for the final report,” Naidu told reporters.
Air India, in a statement, said it is fully cooperating with authorities investigating the crash.
“Air India is working closely with stakeholders, including regulators. We continue to fully cooperate with the AAIB and other authorities as their investigation progresses,” it said.
The plane’s black boxes — combined cockpit voice recorders and flight data recorders — were recovered in the days following the crash and later downloaded in India.
Indian authorities had also ordered deeper checks of Air India’s entire Boeing 787 Dreamliner fleet to prevent future incidents. Air India has 33 Dreamliners in its fleet.