The switches may not have caused the emergency but evidence of a last-ditch effort to save the aircraft.
A year after Air India Flight 171 fell from the sky above Ahmedabad in 32 seconds, killing all 260 people aboard, investigators find themselves no closer to a definitive answer about why a state-of-the-art Boeing 787 lost power moments after leaving the ground. The evidence is strange and contested: fuel-control switches moved to cutoff in the critical seconds after takeoff, a haunting cockpit exchange in which each pilot denied touching them, and a web of competing theories that no single piece of data has yet resolved. What endures, beyond the grief of families and the frustration of safety experts, is a reminder that even in an age of extraordinary technological sophistication, the causes of catastrophe can remain stubbornly, painfully opaque.
- Twelve months after the crash, India's accident investigation bureau released an anniversary update that offered almost nothing new — the mystery has deepened rather than narrowed.
- The central tension is a pair of fuel-control switches that moved to cutoff seconds after takeoff, protected by physical latches designed to prevent accidental use, with cockpit audio capturing each pilot denying responsibility.
- Pilot unions and victim families are pushing back hard, arguing that investigators have fixated on cockpit actions while neglecting encrypted engine health data and possible technical failures that could tell a very different story.
- Competing hypotheses — deliberate crew action, a desperate emergency procedure, a catastrophic electrical fault that may have cut fuel automatically — remain unresolved, with engine temperature data and full cockpit voice transcripts still under analysis.
- The investigation is now shadowed by institutional pressures: families protecting the reputations of deceased pilots, an airline guarding its safety image, and authorities with a stake in public confidence — factors that veteran investigators acknowledge can delay final conclusions indefinitely.
Twelve months after Air India Flight 171 lifted off from Ahmedabad and fell into a medical college campus 32 seconds later, India's accident investigators have released an anniversary update with almost nothing new to offer. The Boeing 787 Dreamliner carried 260 people toward London; none survived. The central mystery remains intact.
What investigators established early on is strange enough on its own. Seconds after takeoff, both fuel-control switches moved to the cutoff position almost simultaneously — switches that are physically latched and designed to require deliberate action. Cockpit audio captured one pilot asking the other why he had done it. The reply: "I did not." Investigators have never confirmed which voice belonged to whom, but the exchange became the investigation's most contested fragment.
The preliminary findings have provoked fierce pushback. Pilot unions argue that investigators have raced ahead of the evidence by focusing on cockpit actions while ignoring encrypted health-monitoring data from the aircraft's engines and systems. The head of the Federation of Indian Pilots called the preliminary report "incomplete and full of loopholes." A veteran investigator, speaking anonymously, acknowledged that final reports are sometimes delayed when their conclusions are institutionally or politically sensitive — and the pressures here are obvious.
Competing theories have multiplied. Aviation safety consultant John Cox, reviewing hundreds of millions of flight hours across Boeing's wide-body fleet, found no case of a fuel-switch mechanical failure shutting down an engine, placing the odds of two simultaneous failures at "one in a trillion or more." But others suggest the switches may not have caused the disaster at all — that pilots may have been executing an emergency relight procedure after the engines had already begun to fail, making the switch movements a symptom rather than a cause.
A further theory proposes that a major electrical fault triggered a flight computer reboot seconds after takeoff, causing the aircraft's systems to misidentify itself as still on the ground and cut fuel automatically — meaning the cockpit switches were never physically touched. The Ram Air Turbine, the aircraft's emergency power windmill, deployed within roughly five seconds of the fuel cutoff, raising questions about the precise sequence of failures.
The engines themselves offer no obvious explanation. Both GEnx powerplants were well within their service lives. Dual-engine failures on modern airliners are exceptionally rare, and no common cause — contamination, bird strike, ash — has been publicly identified. Experts believe that comparing engine temperature data against the exact timing of the switch movements could finally establish whether power loss preceded or followed the cockpit event. Until the full cockpit voice recording is matched against the aircraft's final seconds of flight data, six major questions remain open, and no one can say when the final report will arrive.
Twelve months have passed since Air India Flight 171 dropped from the sky in 32 seconds. The Boeing 787 Dreamliner, carrying 260 people, lifted off from Ahmedabad on what should have been a routine flight to London. Instead, it fell into a medical college campus. A year later, India's Aircraft Accident Investigation Bureau released its anniversary update on Friday with almost nothing new to say: the analysis continues, the mystery deepens, and the investigators still cannot explain why one of the world's most sophisticated aircraft simply lost all power moments after leaving the ground.
What they do know is strange enough. The preliminary report from last July revealed that seconds after takeoff, both fuel-control switches moved to the cutoff position almost simultaneously. These are not ordinary switches—they are physically latched, protected by locking mechanisms, and designed to require deliberate action. They exist to prevent accidental shutdown. Using them seconds after takeoff makes no sense under normal circumstances. Cockpit audio captured one pilot asking the other why he had done it. The reply came back: "I did not." Investigators never identified which voice belonged to whom, but the exchange hung in the air like an accusation. Many experts saw it as evidence of deliberate action in the cockpit. Others saw something else entirely.
The investigation has become unusually contentious. Pilot unions, victim families, and safety campaigners have pushed back hard against the preliminary findings, arguing that the focus on cockpit actions has raced ahead of the evidence. Captain CS Randhawa, head of the Federation of Indian Pilots, told the BBC that investigators should be paying closer attention to the aircraft's technical condition—encrypted health-monitoring messages that transmit data on engines and critical systems before and during flight. The preliminary report mentioned none of this. "The preliminary report is incomplete and full of loopholes," Randhawa said. A veteran accident investigator, speaking anonymously, acknowledged that final reports are sometimes delayed because their conclusions are "politically or institutionally sensitive." In this case, the stakes are obvious: families defending the reputations of deceased pilots, unions resisting conclusions that implicate the crew, an airline eager to demonstrate sound safety standards, and Indian authorities with a broader interest in preserving confidence in the country's aviation system.
Competing theories have emerged about what the fuel switches actually mean. John Cox, a former airline pilot and aviation safety consultant, reviewed the accident histories of Boeing's 757, 767, 777, 787, and 737 Max fleets—more than 400 million flight hours combined. He found no case in which a switch failure shut down an engine. The chances of two such failures occurring within a second of each other, he says, are "one in a trillion or more." But Simon Hradecky of The Aviation Herald has proposed a different interpretation: the switches may not have caused the emergency at all. If the engines were already losing thrust, the pilots may have been executing Boeing's dual-engine failure memory procedure, which requires moving both switches to cutoff and back to run to reset engine controls and attempt a relight. Under this reading, the switch movements would not be the cause but evidence of a desperate attempt to save the aircraft.
Other mysteries compound the uncertainty. The Ram Air Turbine—essentially the aircraft's emergency windmill—deployed within about five seconds of the fuel switches being cut off. But did it deploy earlier than investigators currently believe, perhaps before the engines lost power? One theory advanced by safety campaigners suggests a major electrical fault triggered a reboot of the flight computers seconds after takeoff, causing systems to misidentify the aircraft as being on the ground and cut fuel to both engines. Under this scenario, the cockpit fuel switches were never physically moved at all. Indian investigative journalist Rachel Chitra has highlighted what she sees as inconsistencies in the preliminary report, including questions about the engines' attempted relight after fuel was restored.
The engines themselves present another puzzle. Both GE Aerospace GEnx engines were well within their expected service life, with roughly 28,000 and 33,000 flight hours respectively. Dual-engine failures on modern airliners are exceptionally rare. When they occur, investigators usually find a common cause—fuel contamination, bird strikes, volcanic ash, or some broader system failure. None has been publicly identified here. Experts believe the answer may lie in the engines' Exhaust Gas Temperature, recorded by the flight data recorder. By comparing the moment this temperature began to fall with the recorded movement of the fuel switches, investigators could establish whether the engines started losing power before or after the switches moved. Peter Goelz, a former managing director of the US National Transportation Safety Board, suggested last year that there is likely much more on the cockpit voice recorder than has been released. "A single remark—'why did you cut off the switches?'—isn't enough," he said. Only when the full cockpit conversation is matched against the aircraft's final seconds of recorded data may a clearer picture emerge. For now, the investigation enters its second year with six major questions still unanswered and no certainty about when the final report will arrive.
Notable Quotes
The preliminary report is incomplete and full of loopholes.— Captain CS Randhawa, head of the Federation of Indian Pilots
There is likely much more on the cockpit voice recorder than has been released. A single remark isn't enough.— Peter Goelz, former managing director of the US National Transportation Safety Board
The Hearth Conversation Another angle on the story
Why hasn't the investigation produced a final report after a full year? That seems like a long time.
It does, but air crash investigations rarely move quickly. The Air France 447 inquiry took three years. What matters here is that if investigators had found a clear cause, the report would likely be out by now. The delay itself suggests they're weighing multiple competing hypotheses.
So they genuinely don't know what happened?
They know some things with certainty—the switches moved, the engines lost power, the aircraft fell. What they can't determine is the sequence and causation. Did the switches cause the engine failure, or were the pilots responding to an engine failure that was already happening?
And that distinction matters because?
Because it changes everything about how we understand the disaster. If a pilot deliberately cut the switches, that's one kind of tragedy. If the switches moved because of a mechanical or electrical fault, that's another. If the pilots were trying to save the aircraft, that's a third story entirely.
The cockpit audio seems pretty damning though—one pilot asking why the other cut the switches.
It does sound that way. But we're hearing one sentence out of context. The full cockpit voice transcript might reveal something entirely different. And some experts argue the pilots may have been executing an emergency procedure, not causing the emergency.
What would change the investigation's direction at this point?
Engine temperature data matched against the switch movements. Encrypted health messages from before the flight. The full cockpit conversation. Any of these could shift the entire interpretation of what happened in those 32 seconds.