An American lawyer representing more than 130 survivors and bereaved families of Air India Flight 171 has submitted flight simulator test data to aviation authorities in the United States and the United Kingdom, contending that the findings may contradict key elements of the timeline set out in the preliminary investigation report into the Ahmedabad crash. The submission, dated 11 June, was made by D. Michael Andrews of the Beasley Allen Law Firm in Montgomery, Alabama.

What the Simulator Tests Found

Andrews said a series of tests were conducted in a certified full-motion Boeing 787 flight simulator to examine the timing of the aircraft's Ram Air Turbine (RAT) deployment and its power generation relative to changes in the fuel system. According to Andrews, the simulator tests produced results that diverge from the sequence described in the Aircraft Accident Investigation Bureau (AAIB) preliminary report.

The preliminary report stated that fuel system interruption occurred at 08:08:42 UTC and that the RAT hydraulic pump began supplying hydraulic power approximately four to five seconds later, with flight recorder data placing RAT hydraulic power generation at around 08:08:47 UTC. The simulator testing, by contrast, indicated that RAT-generated power was not produced until approximately 18 seconds after fuel system interruption.

The Core Legal Argument

On the basis of this discrepancy, Andrews argued that 'if the reported timestamps are accurate and the simulator results reflect real-world performance, the RAT would have needed to deploy several seconds before the fuel interruption occurred.' The letter contends that such a scenario could suggest the RAT deployment was not triggered by fuel system changes, but may instead have been associated with an earlier, as-yet-unidentified fault.

Andrews also referred to still images extracted from airport security camera footage which, he said, appeared to show the RAT already deployed while the aircraft was still on the runway, before rotation for take-off. He noted that the preliminary report itself included photographs showing the RAT deployed during the aircraft's initial climb immediately after lift-off.

What the Preliminary Report Said

The AAIB preliminary report, released in July 2025, found that shortly after the aircraft — a Boeing 787-8 registered as VT-ANB — became airborne, both engine fuel control switches transitioned from the RUN position to CUTOFF one second apart, resulting in a loss of fuel supply to both engines. Cockpit voice recordings captured one pilot asking the other why he had 'cut off', with the second pilot replying that he had not done so. The switches were subsequently returned to RUN and engine relight attempts began, but the aircraft was unable to recover altitude.

Flight 171 crashed less than a minute after take-off from Ahmedabad on 12 June 2024, while operating a scheduled service to London Gatwick. The accident killed 241 of the 242 people on board and 19 people on the ground, making it one of the deadliest aviation disasters in recent Indian history.

Where the Investigation Stands

The submission was forwarded to the US Department of Transportation, the Federal Aviation Administration (FAA), and the UK Air Accidents Investigation Branch (AAIB) for evaluation as part of their involvement in the ongoing probe. On the first anniversary of the crash, the AAIB confirmed that significant work had been completed on flight data, engine examinations, maintenance records, and operational documentation, but said no timeline had been set for publication of the final report. The investigation remains ongoing.