2025-06-12
Air India
Flight AI171
Departure
Sardar Vallabhbhai Patel International Airport, Ahmedabad, India
Destination
London Gatwick Airport, London, United Kingdom
Causation Breakdown
Recurrence Likelihood Today
Low
Formal safety recommendations are pending the final investigation report. Redesigned switch guards and revised crew protocols for fuel system management during takeoff are expected to be mandated. The specific failure mode — fuel switch movement seconds after liftoff — is rare in commercial aviation history, though the design vulnerability has been known since at least 2018.
Summary
Air India Flight 171 crashed 32 seconds after takeoff from Ahmedabad, killing 241 of the 242 people on board and 19 on the ground. The aircraft struck a medical college hostel, destroying several buildings. The only survivor was a 40-year-old British passenger. The preliminary investigation found both engines were cut off by fuel switch movement within 3 seconds of liftoff — whether deliberate or accidental remains under active investigation. It is the deadliest aviation accident in India's history and among the deadliest globally in decades.
Cause & Investigation
Determined cause
Fuel control switch cutoff during takeoff
Both fuel control switches were moved from RUN to CUTOFF in sequence, one second apart, just three seconds after liftoff. Both engines immediately lost thrust. The aircraft reached a maximum altitude of approximately 625 feet before losing all power. Despite automatic engine restart attempts and deployment of the ram air turbine, recovery was impossible at that low altitude. The aircraft struck the B.J. Medical College hostel complex 1.7 kilometres from the runway. The preliminary report noted cockpit voice recordings of one pilot questioning why the other had 'cut off,' with a denial of involvement — the deliberate or accidental nature of the switch movement remains under investigation.
Investigation body
Aircraft Accident Investigation Bureau (AAIB), India — with participation from the UK Air Accidents Investigation Branch (AAIB), U.S. NTSB, FAA, and GE Aerospace.
Timeline & Safety Improvements
Flight AI171 disaster
Boeing 787-8 Dreamliner operating for Air India. 260 fatalities, 1 survivors.
Formal investigation opened
Conducted by: Aircraft Accident Investigation Bureau (AAIB), India — with participation from the UK Air Accidents Investigation Branch (AAIB), U.S. NTSB, FAA, and GE Aerospace.
Cause determined: Fuel control switch cutoff during takeoff
Both fuel control switches were moved from RUN to CUTOFF in sequence, one second apart, just three seconds after liftoff. Both engines immediately lost thrust. The aircraft reached a maximum altitude of approximately 625 feet before losing all power. Despite automatic engine restart attempts and deployment of the ram air turbine, recovery was impossible at that low altitude. The aircraft struck the B.J. Medical College hostel complex 1.7 kilometres from the runway. The preliminary report noted cockpit voice recordings of one pilot questioning why the other had 'cut off,' with a denial of involvement — the deliberate or accidental nature of the switch movement remains under investigation.
Improvement implemented
The FAA's 2018 Special Airworthiness Information Bulletin on fuel switch stop-lock disengagement on Boeing 787 systems has been revisited by regulators.
Improvement implemented
Calls for redesigned fuel control switch guards that prevent inadvertent or unauthorized movement during critical flight phases.
Improvement implemented
Review of crew access protocols and cockpit security procedures during takeoff roll and initial climb.
Improvement implemented
Investigation ongoing — formal safety recommendations expected upon release of the final report.