Both fuel cutoff switches moved to the off positions shortly after doomed Air India Flight 171 took off on June 12, according to the preliminary accident investigation report.
The report, released by India’s Air Accident Investigation Bureau, doesn’t draw conclusions on the cause of the crash, but its details will place scrutiny on the pilots.
The bureau said the crash killed 260 passengers, crew and bystanders. The flight had been bound from Ahmedabad to London Gatwick, but crashed soon after takeoff. It was operated with a Boeing 787 Dreamliner and powered by two General Electric GEnx turbofan engines.
The engine cutoff switch is typically used by pilots to power down a plane upon landing. The report states that just three second after liftoff, the cutoff switches from both engines moved from the “run” position to the “cutoff” position.
“In the cockpit voice recording, one of the pilots is heard asking the other why did he cut off,” the report reads. “The other pilot responded that he did not do so.”
The co-pilot was flying the plane at the time, with the captain taking a monitoring role. The report does not state which pilot asked about the fuel cutoff switches being turned off and which responded that he had not turned them off.
Ten seconds after the switches moved to the cutoff position, the switch for engine one was turned back to the “run” position, the reports states. The engine two switch was turned back on four seconds after that.
Both engines showed immediate signs of being reignited. Engine one began to recover thrust prior to the crash, but engine two did not.
The flight transmitter stopped recording, indicating the crash, just 32 seconds after liftoff.
At this stage, there are no recommended actions for operators or manufacturers of Boeing 787-8 planes or GEnx engines, according to the report.
The investigation into the crash is continuing.