Ahmedabad, June 14 (IANS) An American lawyer representing more than 130 people affected by the crash of Air India Flight 171 has submitted flight simulator test data to aviation authorities in the United States and the United Kingdom, arguing that the findings may challenge elements of the timeline set out in the preliminary investigation report into the disaster.

In a letter dated June 11, D. Michael Andrews, associated with Beasley Allen Law Firm in Montgomery, Alabama, said he had provided the findings 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 investigation.

Andrews said he represents more than 130 clients who were injured or lost family members in the crash of Air India Flight 171, a Boeing 787-8 registered as VT-ANB, which crashed shortly after take-off from Ahmedabad on June 12 last year.

The letter states that a series of tests were recently conducted in a certified full-motion Boeing 787 flight simulator to examine, among other issues, the timing of deployment and power generation by the aircraft’s Ram Air Turbine (RAT) in relation to changes in the fuel system.

According to Andrews, the simulator testing produced results that differ from the sequence described in the Aircraft Accident Investigation Bureau’s (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 about four to five seconds later.

Flight recorder data cited in the report placed RAT hydraulic power generation at approximately 08:08:47 UTC.

The lawyer said simulator testing indicated that RAT-generated power was not produced until around 18 seconds after fuel system interruption.

On that basis, he 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 that the RAT deployment was not triggered by fuel system changes but may instead have been associated with an earlier 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 included photographs showing the RAT deployed during the aircraft’s initial climb immediately after lift-off.

The AAIB’s preliminary report, released in July 2025, found that shortly after the aircraft 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 the 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 report said 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 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.

The investigation remains ongoing.

On the first anniversary of the crash, the AAIB said significant work had been completed on flight data, engine examinations, maintenance records and operational documentation, but no timeline had been set for publication of the final report.

–IANS

mys/pgh