Air India Flight AI171 Preliminary Report: A Dual Engine Shutdown Caused the Tragedy in Ahmedabad
Flight recorders from the crashed Air India Boeing 787 in Ahmedabad reveal that the fuel switches were moved to the cutoff position seconds after takeoff.
India's Aircraft Accident Investigation Bureau (AAIB) has published its preliminary report on the crash of Air India Flight AI171 , which occurred on June 12. Data recovered from the flight recorder (EAFR) of the Boeing 787-8, registration VT-ANB , indicates that the catastrophic sequence began when the fuel cutoff switches for both engines were moved from the "RUN" to the "CUTOFF" position just three seconds after the aircraft took off from Sardar Vallabhbhai Patel International Airport (VAAH).
The flight, bound for London's Gatwick Airport (EGKK), was carrying 230 passengers and 12 crew members. The aircraft crashed at approximately 08:09 UTC in a residential area 0.9 nautical miles from the end of runway 23 , resulting in the deaths of all crew members, 229 passengers, and 19 people on the ground. Only one passenger survived with serious injuries.
According to the Enhanced Airborne Flight Recorder (EAFR) data, the aircraft lifted off at 08:08:39 UTC. Three seconds later, upon reaching a speed of 180 knots, the fuel switches for the GEnx-1B engines were moved to the cutoff position, interrupting the fuel flow.
The cockpit voice recording captured a crucial exchange between the pilots. One of them asked the other why he had cut off the engines, to which the second pilot replied that he had not done it. This conversation suggests the action was unexpected and unintentional by the crew.
As a direct consequence of the loss of power from both engines, the Ram Air Turbine (RAT) automatically deployed to supply emergency hydraulic power, a fact confirmed by both flight data and airport security camera footage.
What We Know So Far
What was the main cause of the Flight AI171 accident? The preliminary report indicates that the fuel switches for both engines were moved to the "CUTOFF" position seconds after takeoff, causing a dual engine shutdown.
Was it an intentional action by the pilots? The cockpit voice recording suggests it was not. One pilot expressed surprise, and the other denied having moved the switches.
Was there a known issue with the aircraft? A 2018 FAA bulletin warned of a potential problem with the locking feature of the fuel control switches on this aircraft model. The recommended inspections were advisory and had not been performed on the aircraft.
Twelve seconds after the initial cutoff, the crew attempted a relight by moving the switches back to the "RUN" position. Engine 1 showed signs of recovery, but Engine 2 failed to regain its core speed before the aircraft impacted several buildings of the BJ Medical College complex. The crew transmitted a "MAYDAY" call at 08:09:05 UTC, seconds before the recording stopped.
The report also highlights a relevant contextual factor. In December 2018, the U.S. Federal Aviation Administration (FAA) issued Special Airworthiness Information Bulletin (SAIB) NM-18-33. This document warned of the "potential disengagement of the fuel control switch locking feature" on several Boeing models, including the 787. A disengaged locking feature could make the switches more susceptible to accidental movement.
Air India confirmed to investigators that the inspections suggested in the SAIB were not carried out on VT-ANB because the bulletin was advisory and not a mandatory airworthiness directive.
The investigation, led by India's AAIB, includes collaboration with the U.S. NTSB, as well as technical advisors from Boeing, GE Aviation, and the FAA. The team of investigators continues to analyze the evidence and, at this stage, has not issued safety recommendations for operators of Boeing 787 aircraft or GEnx-1B engines.
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