One year after the crash of Air India flight AI171, the Aircraft Accident Investigation Bureau on Friday released a second interim report on the tragedy that claimed 260 lives. The AAIB revealed that significant progress has been made in the investigation into the crash of Air India Flight AI-171, as it marked one year since the fatal accident involving the Boeing 787-8 aircraft that went down shortly after take-off from Ahmedabad on June 12, 2025.Also read: Boeing, civil aviation minister issue key statement on Air India AI-171 crash probeThe AAIB also cautioned stakeholders, including the media and the public, against drawing premature conclusions while the investigation remains underway. It stressed that the objective of an accident investigation is to improve aviation safety through lessons learned and safety recommendations, rather than assigning blame or liability.In a statement issued on the anniversary of the crash, the AAIB expressed its deepest condolences to the families of those who lost their lives and acknowledged the continuing grief of all those affected by the tragedy.The London Gatwick-bound Boeing 787 Dreamliner crashed into the hostel complex of Ahmedabad's BJ Medical College shortly after taking off from Ahmedabad airport on June 12, 2025. Of the 242 people on board, 241 were killed, along with several people on the ground, taking the death toll to 260. The accident marked the first fatal crash involving Boeing's 787 Dreamliner since the aircraft entered commercial service in 2011.The investigation bureau said the investigation is being carried out in accordance with the Aircraft (Investigation of Accidents and Incidents) Rules, 2017, and the standards prescribed under ICAO Annex 13. A preliminary report containing factual information related to the accident was released on July 12, 2025.According to the AAIB, investigators have over the past year conducted an extensive examination of all relevant technical, operational, organisational and human factors linked to the accident. The probe has been supported by accredited representatives, technical advisers and subject matter experts from various organisations. It further highlighted that "substantial progress" has been achieved in the analysis of aircraft systems, flight recorder data, engine-related components, maintenance records, operational documentation and other evidence gathered during the course of the investigation."The evidence gathered and the results of various examinations are currently being analysed in a comprehensive and integrated manner," the Ministry of Civil Aviation said, adding that additional technical evaluations and specialist examinations would continue wherever necessary to ensure findings are backed by verified evidence and scientific analysis.Reiterating its commitment to an independent and evidence-based investigation, AAIB said the final report will be released only after completion of all investigative activities and the international review and consultation processes mandated under ICAO regulations.As the first anniversary of the tragedy approached, the investigation remained unfinished and was accompanied by disputes over compensation, legal challenges to the inquiry, and continuing debate over the possible causes of the crash.Also read: Air India plans to downsize with owner Tata balking at losses Compensation disputes and legal challengesOne of the most visible controversies emerged around compensation offered to victims' families. Vijay Rupani, the former Gujarat chief minister who was among those killed in the crash, became the focus of a public dispute after his daughter alleged that families were being asked to waive legal rights while accepting compensation settlements.Air India rejected the allegation, saying there was "absolutely no deadline or pressure" on families to accept compensation offers and that relatives were free to wait for the outcome of the investigation before deciding on final settlements. The airline also defended indemnity clauses in settlement documents, saying they were standard industry practice and intended to ensure finality of settlements rather than protect aircraft manufacturers or other third parties from liability.The airline and Tata Sons have continued compensation and support efforts over the past year. Air India said families of 96% of those who died had received its interim compensation payment of ₹25 lakh, while 91% had received the ₹1 crore ex-gratia assistance announced through the AI171 Memorial and Welfare Trust. The carrier has also begun discussions on final settlements, which are calculated individually under international aviation compensation rules based on factors such as age, income and dependants.The investigation itself has also come under scrutiny. The Federation of Indian Pilots (FIP) renewed its demand for a judicial inquiry into the crash and urged authorities not to release an interim report, arguing that partial findings could fuel speculation. The pilots' body has also sought additional technical examination of the aircraft and its systems while questioning aspects of the investigation process.Why the final report is still pendingThe Aircraft Accident Investigation Bureau (AAIB) was expected to provide an update around the first anniversary of the accident. However, investigators are not expected to issue a final report yet, with the probe continuing nearly a year after the crash.The delay is reportedly linked to ongoing technical analysis, including examinations of the aircraft's GE Aerospace engines and related systems. Investigators have conducted engine testing and coordinated with international agencies as part of the process.The inquiry involves multiple stakeholders, including Boeing, Air India, the US National Transportation Safety Board and British investigators. Under International Civil Aviation Organisation (ICAO) rules, draft findings must be circulated among participating parties for comments before a final report can be published. That process has not yet been completed.As a result, investigators are expected to release an interim statement rather than a final report. ICAO guidelines require annual progress updates when an investigation cannot be concluded within one year.From 'run' to 'cutoff': What the first preliminary report revealedThe AAIB's preliminary report, released in July 2025, provided the first detailed account of the aircraft's final moments. According to investigators, the Boeing 787 lifted off normally before both engine fuel control switches moved from the "RUN" position to "CUTOFF" within a second of each other, cutting fuel supply to both engines.Cockpit voice recordings captured one pilot asking the other why he had cut off fuel, while the second pilot responded that he had not done so. The report said the aircraft immediately began losing thrust and altitude. The crew attempted to restore engine power by moving the switches back to the "RUN" position, triggering automatic relight procedures. One engine showed signs of recovery while the other struggled to regain power.Seconds later, a mayday call was transmitted before flight data recording ended. The preliminary report did not identify any fault with the Boeing 787 or its GE engines and issued no safety recommendations for either manufacturer.