The focus of the Air India crash probe centers around the fuel cutoff switches and how they were positioned moments before the deadly incident. A preliminary report by India's Aircraft Accident Investigation Bureau (AAIB) reveals that the fuel control switches for both engines were abruptly moved to the "cutoff" position shortly after takeoff. This action starved the engines of fuel, leading to a loss of thrust and the subsequent crash.
Fuel cutoff switches are designed to shut down the engines by stopping the fuel supply. In standard operating procedures, these switches are primarily used to turn off engines once the aircraft has reached its gate at the airport. They also serve as a critical safety mechanism in emergency situations, such as an engine fire. Flipping the switch to the cutoff position almost immediately cuts off the engine.
The preliminary report indicates that just three seconds after the Boeing 787 Dreamliner took off from Ahmedabad, en route to London, both engine fuel cutoff switches transitioned from the "run" to "cutoff" position within one second of each other. As a result, the engines began to lose thrust, and the aircraft started to descend. The pilots, who had approximately 19,000 hours of flying experience between them, including 9,000 hours on the 787, radioed a "Mayday" call. One pilot was heard on the cockpit voice recorder asking the other why he cut off the fuel, to which the other responded that he did not.
Investigators are now trying to determine how the fuel cutoff switches were activated. The report does not offer any conclusions or apportion blame for the June 12 disaster that killed at least 260 people. Notably, the report also mentioned that at the crash site, both fuel switches were found in the run position, and there had been indications of both engines relighting before the crash.
Several possibilities are being considered, ranging from accidental engagement to a deliberate act. Aviation experts suggest that it is unlikely for a pilot to move the fuel switches accidentally. According to aviation expert David Learmount, the fuel switches cannot be turned on or off by mistake. They have to be pulled out before selecting up (run) or down (cut off). Adding to this, US aviation safety expert John Cox told Reuters that it would not be possible for a pilot to accidentally move the fuel switches. "You can't bump them and they move," he said.
The investigation is ongoing, with investigators analyzing data from the flight data recorders and cockpit voice recorders to understand the sequence of events leading to the crash. The AAIB has not yet issued any recommendations to Boeing 787-8 and GE GEnx-1B engine operators and manufacturers, suggesting that no significant fault has been found with the plane or its engines.
