One year after the crash of Air India Flight 171 shortly after takeoff from Ahmedabad, investigators have not reached a final conclusion about what caused the tragedy that claimed 260 lives.

According to the investigation’s preliminary report, the aircraft’s fuel-control switches for both engines moved to the “cut-off” position within seconds of takeoff, causing both engines to lose fuel and thrust. The cockpit voice recorder also captured one pilot asking the other why the switches had been moved, with the other pilot replying, “I did not.” Investigators have not identified which pilot made either statement, nor have they concluded how or why the switches changed position.

The aircraft involved was a Boeing 787 Dreamliner, one of the world’s most advanced commercial airliners. Aviation experts, including former airline pilot and safety consultant John Cox, have noted that accidental movement of these guarded switches is considered extremely unlikely. Cox has stated that he is unaware of any documented case across the Boeing 757, 767, 777, 787, or 737 MAX fleets in which a switch malfunction alone caused an engine shutdown, making two nearly simultaneous unintended movements extraordinarily improbable.

Despite these observations, investigators have emphasized that no determination of pilot error, mechanical failure, or deliberate action has been made. The Aircraft Accident Investigation Bureau> (AAIB) continues to analyze flight recorder data, aircraft systems, maintenance records, operational procedures, and human factors before issuing its final report.