Cockpit Mystery

The Aircraft Accident Investigation Bureau (AAIB), which released its preliminary report into the Air India Flight 171 crash which killed more than 260 people in Ahmedabad on June 12, leaves more questions than answers.

The 15-page document provides the first official timeline of what transpired aboard the Boeing 787-8 Dreamliner in the final 32 seconds after take-off. While it stops short of assigning responsibility, it confirms that both engine fuel control switches were moved from ‘RUN’ to ‘CUTOFF’ shortly after take-off within one second of each other, causing an immediate loss of engine thrust.

Chilling cockpit voice recordings captured one pilot asking the other why the fuel had been cut off. What is mystifying is that ten seconds later, both switches were moved back to the ‘RUN’ position. But by then, the aircraft had lost too much altitude to recover.

The AAIB report rules out several common causes like fuel contamination and bird strike. Maintenance records showed no prior fault with the fuel control switches. The crew were experienced and medically cleared. CCTV footage confirmed that both pilots boarded the aircraft in normal condition.

Yet the central mystery remains that if the crew did not intentionally shut down the engines, what did? The focus is now shifting to aircraft systems. The AAIB’s report refers to a 2018 Special Airworthiness Information Bulletin (SAIB) issued by America’s Federal Aviation Administration (FAA) which cautioned airlines about a possible locking fault in the 787’s fuel control switches. The switches, if not properly secured, could move unintentionally under certain conditions. But since the bulletin was advisory, not mandatory, AI did not carry out the suggested inspections.

Another warning had surfaced in 2021. A service bulletin issued jointly by the FAA and General Electric had flagged a defect in the electronic engine control (EEC) microprocessor. Thermal cycling over time, it warned, could cause solder joints to fail, potentially disrupting the engine’s fuel control logic. The bulletin recommended replacing the MN4 microprocessor, but again, the recommendation carried no enforcement.

This raises larger questions. Why have regulators allowed airlines to treat such advisories as optional? Why did Boeing not insist on a global compliance mandate, particularly for a high-tech aircraft with a known history of electrical and software issues?

For Boeing, the crash marks the first fatal accident involving a Dreamliner, a model that has been praised for its efficiency and derided for its supply-chain shortcuts. For regulators, particularly India’s Directorate General of Civil Aviation (DGCA), the incident underscores the gap between guidance and enforcement.

To date, no safety bulletins or operational directives have been issued for other Boeing 787 operators. That may change when the final report is released sometime in June 2026.

The preliminary findings in the AI171 case point toward a systems-level malfunction or interface design problem that allowed a catastrophic shutdown to occur within seconds of liftoff.

What remains unanswered is how and why. Until those questions are settled, every take-off on a Dreamliner carries a whisper of uncertainty.