A preliminary report regarding the Air India flight AI171 crash last month, which killed 260 people, indicates that the fuel supply to the aircraft's engines was cut off moments before the crash. The report, issued by India's Aircraft Accident Investigation Bureau (AAIB) on Friday, July 11, 2025, revealed that the fuel control switches for both engines were moved from the "run" position to "cutoff" position shortly after the takeoff on June 12.

The incident occurred on a Boeing 787 Dreamliner, which was en route from Ahmedabad Airport to Gatwick. The aircraft crashed into a residential area shortly after departure.

The preliminary report stated that the engine 1 and engine 2 fuel cutoff switches changed from the "RUN" to "CUTOFF" position in quick succession, with only a one-second gap between them. As a result, the engine speed (N1 and N2) began to decrease from their takeoff values due to the disruption in the fuel supply.

Notably, the cockpit voice recording revealed a conversation between the pilots concerning the fuel cutoff. One pilot is heard questioning the other about initiating the cutoff, to which the other pilot denied doing so.

Following the cutoff, attempts were made to restart the engines. The fuel supply was restored to both engines, leading to a restart of each engine, one after the other. Engine 1 managed to recover and reverse the deceleration caused by the cutoff. However, while engine 2 did restart, it was unable to regain stable thrust. Despite repeated attempts to increase power by reintroducing fuel, the engine's core continued to lose speed, preventing it from returning to normal performance. The pilot then transmitted a "MAYDAY" call.

The AAIB's preliminary report does not offer any conclusions or assign blame for the accident. The report also indicated that there had not been any reported defects related to the fuel control switch since 2023. The left engine had been installed on March 26, and the right engine was installed on May 1, according to the report.

Air India has acknowledged receipt of the preliminary report and stated that they are cooperating fully with the AAIB and other authorities in the ongoing investigation. They also expressed solidarity with the families affected by the accident. At this stage of the investigation, no actions have been recommended to B787-8 and/or GE GEnx-1B engine operators and manufacturers.