Mumbai: The Aircraft Accident Investigation Bureau (AAIB) is expected to release either an interim or final report on Friday, the first anniversary of the Air India Boeing 787 Ahmedabad accident that killed 260 people. The report, even if interim, is expected to answer some of the most important questions, including the reason behind the movement of fuel cutoff switches seconds after lift-off.International Civil Aviation Organisation’s Annex 13, which lays down guidelines for accident investigations states that if a final report cannot be made public within 12 months of an accident, then the country should release an “interim statement publicly on each anniversary of the occurrence, detailing the progress of the investigation and any safety issues raised”. Air safety experts said even if the AAIB releases only an interim report and it follows the ICAO norms, then the black box data should be shared and it would answer some of the core questions.The AAIB’s preliminary report, released a month after the accident, had revealed that both engine fuel control switches moved from ‘RUN’ to ‘CUTOFF’ just seconds after lift-off, cutting fuel supply to both engines. The report revealed a brief exchange in which one pilot asked the other why he had cut off, only to be told that he had not done so. It was implied that the pilots were speaking about fuel control switches .That disclosure led to two sharply different theories, one which suggested deliberate pilot action and the other which argued that a technical malfunction triggered a sequence of events that ultimately resulted in the fuel switches moving.“A crucial piece of the puzzle will come from the time stamp for the aircraft’s Ram Air Turbine (RAT) deployment,” said a B787 examiner, requesting anonymity. RAT is the Boeing 787’s last-resort emergency power source. The AAIB’s preliminary report said CCTV footage showed the RAT deployed “during the initial climb immediately after lift-off”. Pilot groups have argued that the next report must establish precisely when the RAT deployment sequence began. “If investigators find that the RAT deployed before the fuel switches moved, it would point towards a total electrical failure which then caused the fuel switches to move to cutoff. It would absolve the pilot,” the examiner said. “AAIB would already have the timestamps of RAT deployment and fuel switch movements taken from the black box data. The question is will it be made public,” he added.Another issue expected to feature prominently is the condition of the aircraft’s tail-mounted black box. Investigators successfully recovered data from the forward Enhanced Airborne Flight Recorder, but the tail-mounted recorder was so badly damaged that it could not be downloaded through conventional methods. The AAIB said the unit suffered extensive impact and thermal damage and that damage to its memory components was severe. Aviation specialists said a detailed explanation of why the aft recorder was damaged so extensively could provide important clues. Unlike the forward recorder, the recorder in the tail section relies entirely on the aircraft’s main electrical system for power. “Had its data been recoverable, it may have helped settle questions about a possible electrical-system failure,” the examiner said.Investigators are also expected to explain why the aircraft’s Emergency Locator Transmitter failed to activate. The report may also provide greater clarity on maintenance items that were open on the aircraft before departure. The preliminary report disclosed that one active Minimum Equipment List item involved the aircraft’s “core network”. “Investigators are expected to address whether that deferred defect had any relevance to the events that unfolded after take-off,” said the examiner.On June 12, 2025, the London-bound Air India flight AI-171 crashed into the hostel complex of BJ Medical College moments after taking off from Sardar Vallabhbhai Patel International Airport in Ahmedabad, killing 241 persons on board and 19 on the ground. Just one passenger survived.
