The preliminary crash report on the June 12 Air India Boeing 787 Dreamliner tragedy has sharply turned attention to a seemingly small but critically important cockpit component: the fuel control switches. The investigation details a haunting and highly unusual failure sequence that led to the loss of both engines just seconds after takeoff, resulting in a crash that killed all 231 passengers and crew aboard.
What Are Fuel Control Switches and Why Are They Critical?
Fuel control switches in the Boeing 787 Dreamliner:
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Are located just beneath the thrust levers.
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Are used to start or shut down engines on the ground and manually shut down/restart engines in flight.
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Are spring-loaded with a locking mechanism that prevents accidental activation—requiring the switch to be pulled up before toggling from “RUN” (fuel ON) to “CUTOFF” (fuel OFF).
These switches control the flow of fuel to the jet engines, meaning a single flip to "CUTOFF" immediately kills the engine. They are a last-resort tool in mid-air emergencies and are typically used only during startup and shutdown procedures on the ground.
What the Report Reveals: Timeline of the Catastrophe
According to the Aircraft Accident Investigation Bureau (AAIB)’s 15-page preliminary report:
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3 seconds after takeoff from Ahmedabad, both fuel control switches moved from “RUN” to “CUTOFF”, almost simultaneously.
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Cockpit Voice Recorder (CVR) captured a chilling exchange:
Pilot 1: “Why did you cut off the fuel?”Pilot 2: “I didn’t.” -
Both switches were returned to “RUN” 13 seconds later, but by then, the engines had lost too much core speed and could not be restarted in time.
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Engine 1 showed signs of core recovery but stalled.
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Engine 2 attempted a relight, briefly igniting before failing again.
How Could This Happen? Switches Are Designed to Prevent Accidental Movement
The simultaneous, near-instantaneous movement of both switches to CUTOFF is baffling and deeply suspicious for several reasons:
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Accidental movement is unlikely due to the need for deliberate action to unlock and toggle the switch.
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The switches are wired independently, powered by separate systems, and have no reported history of malfunction in aircraft VT-ANB since 2023.
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The possibility of pilot error, mechanical fault, or even malicious interference is now under deeper scrutiny.
FAA Warning in 2018 – Overlooked Advisory?
Interestingly, the Federal Aviation Administration (FAA) in 2018 had raised concerns about similar fuel control switches in 737 aircraft, citing risks of inadvertent cutoff due to wiring or actuator issues. However:
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The FAA’s Special Airworthiness Information Bulletin (SAIB) was advisory, not mandatory.
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Air India did not perform the suggested inspections for part number 4TL837-3D, the same type used in this 787 aircraft.
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The AAIB notes:
“The suggested inspections were not carried out as the SAIB was advisory and not mandatory.”
Unanswered Questions and Deepening Mystery
This early report leaves open several critical avenues for further investigation:
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Was there a system malfunction that triggered automatic cutoff?
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Could a software bug or electrical short have overridden pilot controls?
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Could human error or disorientation in the high-stress takeoff moment be to blame?
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Was external tampering or sabotage a factor?
Investigators are now analyzing the Flight Data Recorder (FDR) and mechanical linkages between switches and fuel valves, looking for anomalies, power surges, or transient glitches.
Conclusion: A Small Switch, A Massive Tragedy
The preliminary findings underscore how one brief, unexplained action involving fuel control switches led to dual engine failure—an exceedingly rare event—within seconds of takeoff. Despite their fail-safe design, these switches appear to have functioned (or malfunctioned) in a way that was both catastrophic and irreversible in the tight window available for recovery.
Until the final report confirms root causes—mechanical, procedural, or human—speculation remains dangerous. But what’s already clear is that these switches, though small, had an outsized role in the fate of Air India AI171.
