What Are Fuel Switches? How Did Fuel Switch Cutoff Trigger Air India Plane Crash in Ahmedabad? All You Need To Know

New Delhi, July 12: The preliminary report into the June 12 crash of Air India Flight AI 171 has revealed a disturbing and unusual sequence of events that may have led to the loss of 260 lives. The Aircraft Accident Investigation Bureau (AAIB) of India released a detailed 15-page report—rare for an early-stage investigation—that points to the inadvertent movement of critical engine fuel control switches just seconds after takeoff.

Typically, preliminary reports avoid drawing conclusions, but this one highlights specific technical actions as potential triggers for the disaster. The Boeing 787 Dreamliner, en route from Ahmedabad to London, suffered a sudden loss of engine thrust shortly after liftoff when both engines were briefly starved of fuel. AAIB Preliminary Report on Air India Flight AI171 Crash: Both Engines of Boeing 787-8 Dreamliner Shut Down After Shift in Fuel Control Switches, Cockpit Audio Reveals One Pilot Told Another 'I Didn’t Do It’.

What Are Fuel Switches?

Fuel control switches regulate the flow of fuel into an aircraft’s engines. These switches are essential during engine start-up and shutdown procedures, typically used while the plane is on the ground. In emergencies, like an engine fire, pilots may also operate them mid-air. However, aviation experts stress that it’s virtually impossible to switch them off accidentally due to their design. From Fuel Control Shut Down to ‘Mayday Call’: Highlights From AAIB Report on Air India Ahmedabad Plane Crash.

On the Boeing 787, the switches are located just below the thrust levers. They are spring-loaded and require a deliberate pull-up motion before being moved from “run” to “cutoff” or vice versa. Their tamper-proof design ensures that any movement is intentional and instantly impacts engine function.

How Did Fuel Switch Cutoff Trigger Air India Crash?

According to flight data, both fuel control switches moved from “run” to “cutoff” one after the other—just seconds after takeoff—with a one-second gap between them. This action caused both engines to lose power, resulting in the aircraft’s immediate descent. The cockpit voice recorder captured one pilot asking the other why he had cut the fuel, to which the response was: “I didn’t do it.”

The switches returned to “run” moments later, and were found in that position at the crash site. "No sane pilot would ever turn those switches off in flight," especially as the plane is just starting to climb, said US aviation safety expert John Nance.

Boeing systems typically relight engines automatically when switches are returned to “run,” but by then it was too late to regain lift. The AAIB is continuing its probe, as the aviation world awaits clarity on how such a catastrophic switch movement occurred.

(The above story first appeared on LatestLY on Jul 12, 2025 11:00 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).