Air India crash probe explained: What are fuel switches, how do they work, and why they matter in investigation

A preliminary investigation into the crash of an Air India Boeing 787 Dreamliner that killed 260 people last month has identified a critical and puzzling detail: both engines lost power seconds after takeoff when their fuel control switches flipped to the cutoff position. But how these switches were triggered — and why — remains unanswered.

Here’s a breakdown of what fuel control switches are, how they work, and why they’re now at the centre of the investigation into one of the deadliest air crashes in a decade.

Fuel control switches regulate the flow of fuel to an aircraft’s engines — a critical function for flight safety and engine performance. These switches are used to:

According to aviation experts cited by Reuters, moving these switches to the CUTOFF position immediately halts the fuel supply, causing the engine to shut down. Due to the serious consequences of activation, the switches are designed to prevent accidental movement.

In the Boeing 787 cockpit — including Air India’s GE-powered model — the fuel control switches are positioned directly below the thrust levers on the central console.

Their placement is standard across all 787s and is designed for quick access during critical procedures, while still requiring a deliberate pull-up action to operate, which helps prevent unintentional use.

These switches are now central to an ongoing investigation after both reportedly flipped to CUTOFF seconds after takeoff — a move that caused both engines to lose power and the aircraft to crash. Investigators are still trying to determine how or why this occurred.

On a Boeing 787 Dreamliner, like the one involved in the Air India crash, each engine is managed by its own fuel control switch.

These switches are:

This multi-step mechanism is engineered to prevent accidental activation, especially during flight.

According to the preliminary report by India’s Aircraft Accident Investigation Bureau (AAIB), the Air India jet took off from Ahmedabad on June 12 at 08:08:39 UTC. Just three seconds later:

The cockpit voice recorder captured a moment of confusion:

“Why did you cut off the fuel?” one pilot asked.
“I didn’t,” the other replied.

Ten seconds later, the switches were returned to RUN, and the pilots tried to relight both engines. One engine responded briefly — the other didn’t.

At 08:09:05 UTC, one of the pilots issued a "Mayday" call. Seconds later, the aircraft crashed nose-up into buildings just outside the airport boundary, killing nearly everyone on board and 19 people on the ground.

Both were certified to operate the Boeing 787. Authorities are reviewing their backgrounds and health as part of routine post-crash protocol.

What are investigators looking at?

Investigators are considering three possibilities:

The 2018 FAA bulletin warned of rare cases where fuel switches on Boeing aircraft could be moved without the locking mechanism engaging. However, the advisory was optional, and Air India did not inspect the aircraft for this issue.

At the crash site, both switches were found in the RUN position, and components showed signs the engines may have tried to restart just before impact.

The Dreamliner had a valid airworthiness certificate and no recorded fuel system issues. Some minor maintenance deferrals (Category C and D items) were noted, but none related to engine control.

Key findings from the preliminary report:

This crash marks a major setback for Air India’s revival efforts under the Tata Group, which took over the carrier in 2022. The airline is already facing heightened scrutiny, including separate regulatory investigations into maintenance records and safety violations at its low-cost subsidiary, Air India Express.

The preliminary report confirms that fuel was cut to both engines mid-air — but it does not yet clarify how or why. With experienced pilots at the controls, secure switch designs in place, and no immediate signs of mechanical failure, investigators are now grappling with a rare and perplexing aviation mystery.

Understanding what triggered the fuel cutoff is critical to determining whether this was due to human error, a technical fault, or another unforeseen factor.

With inputs from Bloomberg, AFP