New Delhi [India], July 12 (ANI): India's Aircraft Accident Investigation Bureau (AAIB) released the preliminary report into the tragic crash of Air India flight AI171, a Boeing 787-8 aircraft, which crashed shortly after takeoff from Ahmedabad's Sardar Vallabhbhai Patel International Airport on June 12.

The crash killed 260 people, including 229 passengers, 12 crew members, and 19 people on the ground.

The report outlines a harrowing sequence of events that unfolded within 90 seconds of takeoff, as both engines of the aircraft shut down unexpectedly during the initial climb, leading to a catastrophic loss of thrust and rapid descent.

Flight data recovered from the aircraft's Enhanced Airborne Flight Recorder (EAFR) revealed that the fuel cutoff switches for both engines were inadvertently moved from RUN to CUTOFF, one after another within a 1-second interval, at an altitude just moments after liftoff. One pilot was heard asking the other, 'Why did you cut off?' to which the response was, 'I did not.'

This uncommanded shutdown triggered the deployment of the Ram Air Turbine (RAT), and the aircraft began losing altitude almost immediately, unable to sustain powered flight.

According to the AAIB, the pilots re-engaged the fuel switches in an attempt to relight both engines. Engine 1 showed signs of recovering thrust, but Engine 2 failed to stabilise. The aircraft, which had briefly reached a speed of 180 knots, was already descending and failed to regain altitude. The final distress call -- a 'MAYDAY' -- was transmitted at 08:09 UTC, just seconds before the aircraft crashed into residential buildings outside the airport perimeter.

The aircraft struck several buildings, including the BJ Medical College hostel, causing significant structural and fire damage across five structures. The Emergency Locator Transmitter (ELT) did not activate, and emergency services were mobilized within five minutes of the crash.

The wreckage trail extended over 1,000 feet, with major components including the vertical stabilizer, engines, and landing gear found embedded in buildings and scattered across the crash site.

The aircraft, registered VT-ANB, was delivered in 2013 and had recently undergone routine maintenance. All Airworthiness Directives had been complied with, and the fuel quality was confirmed to be within specifications. There were no reported technical defects linked to the engines or flight control systems immediately prior to the accident.

The pilot-in-command, a 56-year-old with over 15,000 flying hours, and the co-pilot, 32, with over 3,400 hours, were both fully qualified and had no recent duty irregularities or medical issues reported.

A Special Airworthiness Information Bulletin (SAIB) issued by the FAA in 2018 had warned of a potential issue involving the fuel control switch locking mechanism on similar Boeing aircraft.

However, the bulletin was advisory, not mandatory, and Air India had not performed the recommended inspections. The report notes that while the locking feature may have been disengaged, there had been no prior defect reports related to the switch on this aircraft.

The AAIB team, in coordination with investigators from the NTSB (USA), Boeing, GE, FAA, and safety agencies from the UK, Portugal, and Canada (whose citizens were among the victims), is continuing detailed analysis of cockpit recordings, engine components, maintenance records, and pilot actions.

The agency has not issued any immediate safety recommendations, but further assessments are underway, especially regarding design safeguards for fuel control systems and possible human factors.

At this stage of the investigation, the report reads 'there are no recommended actions to B787-8 and/or GE GEnx-1B engine operators and manufacturers.'

Investigation is continuing and the investigation team will review and examine additional evidence, records and information that is being sought from the stakeholders.

The final report is expected in the coming months.

Flight AI171 was a scheduled service from Ahmedabad to London Gatwick, carrying 230 passengers and crew. The crash represents one of the deadliest aviation accidents in India in recent history. (ANI)