Key findings from the AAIB report
After one month of Air India Flight AI171, a Boeing 787-8 Dreamliner bound for London Gatwick from Ahmedabad’s Sardar Vallabhbhai Patel International Airport, crashed just 30 seconds after takeoff, killing 260 people, including 229 passengers, 12 crew members, and 19 individuals on the ground, the Aircraft Accident Investigation Bureau (AAIB) of India released its preliminary report, providing critical insights into the sequence of events leading to the catastrophe, though the exact cause remains under investigation. The report outlines the crash’s impactand the ongoing efforts to uncover the truth behind this tragic event.
Sequence of events
According to the AAIB’s 15-page preliminary report, Flight AI171 took off from runway 23 at 13:38 IST (08:08 UTC) with 230 passengers (including 13 children, 2 infants) and 12 crew members, comprising 169 Indian nationals, 53 British, 7 Portuguese, and 1 Canadian. The flight was commanded by Captain Sumeet Sabharwal (15,600 flight hours, 8,600 on the 787) and First Officer Clive Kunder (3,400 hours, 1,100 on the 787), with Kunder as the pilot flying and Sabharwal monitoring.
Takeoff and immediate failure
At 13:38:42 IST, three seconds after liftoff, the aircraft’s two General Electric GEnx-1B engines lost thrust when their fuel control switches moved from RUN to CUTOFF within a one-second interval, an action requiring deliberate lifting and shifting of each switch. The aircraft reached a maximum airspeed of 180 knots but failed to climb above 625 feet.
Cockpit confusion
Cockpit voice recorder (CVR) data revealed one pilot asking, “Why did you cut off?” with the other responding, “I did not.” The report does not specify which pilot spoke, nor whether the switch movement was intentional or inadvertent.
Failed recovery
The pilots re-engaged the fuel switches at 13:38:52 and 13:38:54 IST, attempting to relight the engines. Engine 1 showed signs of recovering thrust, but Engine 2 did not stabilize. The Ram Air Turbine (RAT) was deployed, indicating a total loss of power, but the aircraft began descending rapidly.
Crash and impact
At 13:39 IST (08:09 UTC), the aircraft issued a Mayday call and crashed into the hostel block of B.J. Medical College, a densely populated area near the airport. The impact caused multiple explosions, damaging five buildings and scattering debris over a 1000ft x 400ft area. The crash killed 241 onboard and 19 on the ground, including former Gujarat Chief Minister Vijay Rupani, and injured 67 others.
Investigation progress
The AAIB, leading the investigation under International Civil Aviation Organization (ICAO) protocols, recovered both Enhanced Airborne Flight Recorders (EAFRs)—combining flight data and cockpit voice functions—on June 13 and 16, 2025. The data from the front recorder was successfully downloaded on June 25 at the AAIB Lab in Delhi, a significant advancement as India previously relied on foreign facilities for such analyses. A digital video recorder from the aircraft’s cameras was also retrieved by the Gujarat Anti-Terrorism Squad.
International collaboration: The AAIB is supported by the UK’s Air Accidents Investigation Branch (four investigators), the US National Transportation Safety Board (NTSB), Boeing, General Electric (GE), and the Indian Air Force. The US Federal Aviation Administration (FAA) stands ready to assist. The investigation includes fuel sample testing, post-mortem reports, and forensic analysis.
Simulator testing: Air India pilots conducted a separate simulator test replicating the flight’s conditions (e.g., deployed landing gear, retracted flaps), ruling out these settings alone as the cause, narrowing the focus to mechanical, electrical, or human factors.
Sabotage angle: Minister of State for Civil Aviation Murlidhar Mohol confirmed that the AAIB is probing all angles, including sabotage, with CCTV footage under review.
Key findings and unanswered questions
The preliminary report highlights several critical points but stops short of assigning a definitive cause:
- Fuel control switch issue: The movement of both fuel control switches to CUTOFF is the primary focus, as this action led to the immediate loss of thrust. A 2018 FAA advisory noted potential disengagement of the fuel control switch locking feature, but Air India did not conduct the optional inspections, as no defects were reported since the throttle control module’s replacement in 2023.
- Pilot interaction: The CVR indicates confusion between the pilots, suggesting the switch movement may not have been intentional, though the report does not clarify the circumstances.
- No immediate mechanical failure: The absence of urgent safety advisories from Boeing, GE, or the AAIB suggests mechanical failure is not the primary suspected cause at this stage.
- Ongoing probes: The investigation continues, with fuel samples, maintenance records, and pilot training under scrutiny. A final report is expected within a year.
Aftermath and response
The crash, the first fatal incident involving a Boeing 787 Dreamliner, has sent shockwaves through India and the global aviation community. The death toll, initially reported at 279 but later revised to 260, includes 241 on board and 19 on the ground. DNA testing identified 119 victims by July 12, with 76 bodies handed over to families. The sole survivor, Vishwash Kumar Ramesh, continues to receive medical care.
Air India’s Response: Air India retired flight numbers AI171 and AI172, renaming the route AI159/AI160. The airline established assistance centers in Ahmedabad, Mumbai, Delhi, and Gatwick, providing support to over 400 family members. Air India is cooperating fully with the AAIB and has faced criticism for inconsistent communication, as noted on X posts expressing public grief and frustration.
Government actions: The Directorate General of Civil Aviation (DGCA) ordered inspections of Air India’s 34 Boeing 787s, focusing on fuel systems, cabin air compressors, and engine controls, with eight aircraft inspected by July 12. A parliamentary committee is reviewing aviation safety, with the crash a key discussion point.
Boeing and GE: Boeing’s CEO Kelly Ortberg expressed condolences and pledged support, deferring to the AAIB per ICAO protocols. GE is assisting with engine-related inquiries.
Broader implications
The crash has raised serious questions about aviation safety in India, reflecting public outrage and calls for accountability. Families, like that of crew member Lamnunthem Singson and passenger Abhinav Parihar, expressed profound grief, with some questioning the value of the investigation, as reported by the BBC.
The AAIB’s preliminary report, while factual and restrained, underscores the complexity of determining why the fuel switches moved, whether due to human error, mechanical fault, or sabotage. The investigation’s outcome will likely influence safety protocols for the Boeing 787 fleet globally, given that this is the aircraft’s first fatal crash. As the probe continues, the focus remains on providing closure to grieving families and ensuring such a tragedy is not repeated.
Conclusion
The AAIB’s preliminary report on Air India Flight AI171 offers critical insights into the catastrophic loss of thrust that led to the Ahmedabad crash, pointing to the mysterious movement of fuel control switches as a key factor. While the investigation, supported by international experts, is far from complete, the findings highlight the need for rigorous safety checks and transparency. The crash has left an indelible mark on India’s aviation history, with the nation mourning the loss of 260 lives and supporting the sole survivor. The families seek answers, and the global aviation community watches closely.
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