The Aircraft Accident Investigation Bureau (AAIB) has released its
preliminary report into the tragic crash of Air India Flight AI171, revealing that both engines lost power within seconds of takeoff due to fuel cutoff switches being moved from the 'RUN' to 'CUTOFF' position. The incident, which occurred on12 June 2025, at Ahmedabad's Sardar Vallabhbhai Patel International Airport, resulted in 260 fatalities, making it one of India's deadliest aviation disasters in recent history.
The Fatal Sequence of Events
According to the preliminary report released by India's Aircraft Accident Investigation Bureau, the Boeing 787-8 Dreamliner experienced a catastrophic loss of thrust just moments after becoming airborne. As reported by
Reuters, the aircraft began to lose thrust and sink shortly after takeoff, with the flight lasting approximately 30 seconds from takeoff to crash. The plane was bound for London from Ahmedabad when disaster struck.
The investigation revealed that almost immediately after the aircraft lifted off, both engine fuel cutoff switches transitioned from the 'RUN' to 'CUTOFF' position within one second of each other. This sudden change starved both engines of fuel, causing an immediate loss of thrust that proved fatal at such a low altitude.
Cockpit Confusion and Final Moments
The preliminary report highlighted significant confusion in the cockpit during the aircraft's final moments. According to
Times of India coverage, cockpit voice recordings captured a critical exchange between the pilots. One pilot was heard asking the other why he had cut off the fuel supply, to which the other pilot responded that he had not done so.
BBC reporting provides additional context, noting that the cockpit voice recording captures one pilot asking the other why he "did the cut-off", to which the person replies that he didn't, though the recording doesn't clarify who said what. This exchange underscores the bewilderment that characterised the crew's final seconds.
The report noted that the switches were eventually moved back to the 'RUN' position 14 seconds after being cut off, triggering the aircraft's automatic engine relight sequence. However, despite the crew's efforts to restore power, the plane could not gain sufficient thrust quickly enough to arrest its descent from the critically low altitude.
Crew Experience and Aircraft Details
The commanding pilot of the Air India aircraft was Captain Sumeet Sabharwal, aged 56, who possessed extensive flying experience totalling 15,638 hours and also served as an Air India instructor. His co-pilot was Clive Kunder, 32, with 3,403 hours of total flying experience, according to
Reuters. Both pilots were considered experienced aviators, making the circumstances surrounding the fuel switch activation even more puzzling.
BBC reported that at the time of take-off, the co-pilot was flying the aircraft while the captain was monitoring, and both pilots had passed breathalyser tests and been cleared fit to fly before boarding Flight 171.
The aircraft involved was a Boeing 787-8 Dreamliner equipped with two General Electric engines. Airport closed-circuit television footage showed that the plane had reached a height of 650 feet after takeoff before suddenly losing altitude and crashing into a nearby building in a devastating fireball.
Technical Analysis of Fuel Control Switches
Aviation experts have emphasized the significance of the fuel control switches in this incident. As explained in the
Times of India report, these switches are specifically designed to prevent accidental activation. They are spring-loaded to remain in their designated position and require deliberate action to move them from 'RUN' to 'CUTOFF' - a pilot must first pull the switch up before moving it.
The switches are located just below the thrust levers on the Boeing 787-8 Dreamliner and are protected by brackets to prevent unintended activation. US aviation safety expert John Nance, quoted by
Reuters, noted that a pilot would normally never turn these switches off in flight, particularly during the climb phase, describing such action as 'absolutely bizarre'.
BBC investigation revealed additional technical details about these switches. According to their reporting, the lever-lock fuel switches are designed to prevent accidental activation—they must be pulled up to unlock before flipping, a safety feature dating back to the 1950s. A Canada-based air accidents investigator told
BBC that "it would be almost impossible to pull both switches with a single movement of one hand, and this makes accidental deployment unlikely." This design feature makes the Air India case particularly perplexing.
Emergency Response and Investigation
The crash site analysis revealed that both fuel switches were found in the 'RUN' position, and there were indications that both engines had begun relighting before the low-altitude impact occurred. The deployment of the ram air turbine (RAT) - a backup power source that activates when both engines fail—was captured in airport closed-circuit television (CCTV) footage, confirming the complete loss of engine power.
The aircraft's black boxes, containing both cockpit voice recordings and flight data, were successfully recovered in the days following the crash and subsequently downloaded in India. The preliminary report, released approximately 30 days after the accident in accordance with international aviation protocols, represents the first official investigation findings.
Additional Technical Findings and Expert Analysis
Further investigation details revealed by BBC show that the aircraft's RAT had deployed - a clear sign of major systems failure. The RAT, a small propeller that extends from the underside of the Boeing 787 Dreamliner, acts as an emergency backup generator that automatically deploys when both engines lose power or if all three hydraulic systems register critically low pressure.
The landing gear was also found in the 'down position' or not retracted, which aviation experts suggest indicates the crew had no time to complete normal takeoff procedures. As explained by a Boeing 787 pilot quoted by BBC, "When both engines fail and the aircraft starts going down, the reaction goes beyond just being startled - you go numb. In that moment, landing gear isn't your focus. Your mind is on one thing: the flight path."
Aviation safety expert Shawn Pruchnicki from Ohio State University, quoted by
BBC, noted that if one of the pilots was responsible for shutting down the switches, it "does beg the question: why. Was it intentional, or the result of confusion? That seems unlikely, as the pilots reported nothing unusual."
The preliminary report noted that all applicable airworthiness directives and alert service bulletins had been complied with on both the aircraft and engines. However, as mentioned in the
Times of India coverage, investigators also noted that a 2018 FAA safety bulletin had warned about possible issues with the locking mechanism of fuel control switches on similar aircraft types.
BBC reporting provides crucial additional context regarding this safety bulletin. According to their investigation, in December 2018, the United States Federal Aviation Administration (USFAA) issued a Special Airworthiness Information Bulletin (SAIB) highlighting that some Boeing 737 fuel control switches were installed with the locking feature disengaged. While the issue was noted, it wasn't deemed an unsafe condition requiring an airworthiness directive. The same switch design is used in Boeing 787-8 aircraft, including Air India's VT-ANB which crashed. As the SAIB was advisory, Air India did not perform the recommended inspections.
The US National Transportation Safety Board (NTSB) acknowledged the cooperation of Indian officials in their investigation statement, noting that no recommended actions for operators of Boeing 787 aircraft or the General Electric engines were included in the preliminary report. The USFAA emphasised its commitment to following the facts and promptly addressing any identified risks.
Industry Impact and Moving Forward
The crash presents significant challenges for Tata group's ambitious campaign to restore Air India's reputation following their acquisition of the carrier from the government in 2022. As reported by
Reuters, the incident has prompted additional scrutiny of Air India operations, with Indian authorities ordering deeper checks of the entire Boeing 787 Dreamliner fleet to prevent future incidents.
Civil aviation minister Ram Mohan Naidu urged caution in drawing conclusions from the preliminary findings, emphasising the need to await the final investigation report before making definitive assessments about the cause of the tragedy.
Conclusion
The preliminary report into Air India Flight AI171 raises more questions than it answers, particularly regarding how and why the fuel control switches were moved to the cutoff position during such a critical phase of flight. While the report establishes the immediate cause of the engine failure, the underlying reasons for the switch activation remain under investigation.
As
BBC reported, families and friends of the crash victims have been anxiously awaiting answers. Imtiyaz Ali, who lost his brother, sister-in-law, and their two young children in the crash, expressed disappointment that the preliminary report 'reads like a product description' and hoped more details would be made public in the months to come.
The final report, expected within a year, will be crucial in determining whether this was the result of mechanical failure, inadvertent crew action, or other factors.
The investigation continues with the support of international aviation authorities, including the US NTSB and Boeing, as the aviation community seeks to understand this tragic incident and prevent similar occurrences in the future.
