Ahmedabad: A recent preliminary report by India's Aircraft Accident Investigation Bureau (AAIB) sheds new light on the tragic crash of Air India Flight AI 171, a Boeing 787 Dreamliner, near Ahmedabad in June that resulted in 260 fatalities, including ground casualties.
The report reveals that both engine fuel control switches were found in the "cut-off" position moments before the aircraft descended uncontrollably. This critical detail raises questions about the sequence of events leading to the crash.
The investigation, which analyzed cockpit voice recorder (CVR) data, uncovered a perplexing exchange between the pilots. One pilot questions the other about why he "did the cut-off," suggesting confusion or a malfunction, as the second pilot denies any action. This interaction underscores the mysterious nature of the final moments of the flight.
At approximately 08:08:42 UTC, the aircraft reached its maximum speed of 180 knots indicated airspeed. Immediately afterward, the fuel cutoff switches on both engines transitioned from "RUN" to "CUTOFF" within a one-second interval. The aircraft then rapidly lost altitude, prompting the crew to issue a "MAYDAY" distress call. Despite attempts to restore engine power, the plane crashed shortly thereafter.
The switches involved are critical safety controls designed to shut down engines or manage fuel flow during emergencies. Typically, these switches have safety features that prevent accidental activation, requiring deliberate actions to operate. The AAIB’s report does not currently explain how or why these switches moved to the "cut-off" position.
The investigation is ongoing, with authorities continuing to analyze wreckage, post-mortem reports, and component inspections. The AAIB has stated that, at this preliminary stage, no immediate recommended actions are being issued for Boeing 787-8 and/or GE GEnx-1B engine operators and manufacturers.
However, experts have noted that a 2018 Special Airworthiness Information Bulletin from the US Federal Aviation Administration (FAA) flagged a "potential disengagement of the fuel control switch locking feature" on similar Boeing models, an advisory which Air India reportedly did not implement as it was not mandatory.
