The Tragic Crash of Air India Flight 171: A Deepening Mystery
On June 12, 2025, Air India Flight 171, a Boeing 787-8 Dreamliner, crashed seconds after takeoff from Ahmedabad Airport in India, en route to London Gatwick. The disaster claimed the lives of 241 of the 242 people on board and 19 individuals on the ground, making it one of the deadliest aviation incidents in recent Indian history.
The preliminary report from India's Aircraft Accident Investigation Bureau (AAIB) has revealed a chilling detail: the fuel control switches for both engines were moved to the "cut-off" position shortly after liftoff, an action requiring intentional mechanical effort. This deliberate act cut off the fuel supply to the otherwise fully functional engines, triggering the deployment of the Ram Air Turbine (RAT) and leading to the catastrophic crash.
The Incident: A Timeline of Catastrophe
Air India Flight 171 took off from Ahmedabad Airport at 13:39 local time (08:09 UTC) with 230 passengers and 12 crew members aboard. The aircraft was commanded by Captain Sumeet Sabharwal, a veteran pilot with over 15,600 flight hours, and First Officer Clive Kunder, who had accumulated over 3,400 hours. The takeoff proceeded normally until, just three seconds after liftoff (08:09:42 UTC), the fuel control switches for both engines were moved to the "cut-off" position, one second apart. This action halted the fuel flow to the engines, causing them to lose power almost instantly.
As the engines failed, the aircraft’s Ram Air Turbine (RAT)—a backup system designed to provide emergency power in cases of engine or hydraulic failure—deployed automatically at 08:09:47 UTC. The pilots attempted to recover by returning the switches to the "run" position at 08:09:52 and 08:09:56 UTC, respectively, prompting the engines to begin relighting. However, the aircraft, still at a low altitude, had insufficient time and thrust to recover. A "mayday" call was issued at 08:10:05 UTC, and the plane crashed into a residential area near the airport six seconds later, at 08:10:11 UTC. The entire sequence from takeoff to impact spanned just 32 seconds, leaving little room for error or correction.
The crash resulted in near-total loss of life on board, with only one survivor, and caused significant destruction on the ground. The preliminary investigation has focused on the fuel switches as the critical factor, raising urgent questions about why they were turned off.
The Fuel Switches: A Deliberate Mechanical Action
The fuel control switches on the Boeing 787 are mechanical devices located between the pilots’ seats, behind the throttle levers, and protected by metal guards. To move a switch from "run" to "cut-off," a pilot must pull it outward against a locking mechanism and then shift it to the desired position. This design ensures that accidental movement—such as a bump or nudge—is virtually impossible. The AAIB report confirms that the switches were moved deliberately, with a one-second interval between the actions, further suggesting a purposeful sequence rather than a random error.
When the switches were moved to "cut-off," the engines—reported to be in good working condition—were starved of fuel and shut down. The subsequent deployment of the RAT indicates a total loss of engine power, a condition that only occurs under specific circumstances such as dual engine failure, complete electrical failure, or loss of all hydraulic systems. In this case, the RAT’s activation was a direct consequence of the fuel cutoff, underscoring the severity of the initial action.
The cockpit voice recorder (CVR) captured a brief exchange between the pilots after the switches were turned off: one asked, "Why did you cut off?" and the other replied, "I didn’t." This conversation reflects confusion rather than clarity, complicating efforts to determine who moved the switches and why. The pilots’ attempt to restore the switches to "run" suggests they recognized the error, but the delay—approximately 10-14 seconds with the switches in "cut-off"—proved fatal.
The RAT Deployment: A Symptom of Engine Failure
The Ram Air Turbine (RAT) is a small wind-driven propeller that deploys automatically to provide emergency electrical and hydraulic power when an aircraft experiences a critical failure. On Flight 171, the RAT activated five seconds after the fuel switches were turned off, confirming that the loss of engine power had crippled the aircraft’s primary systems. The RAT enabled limited functionality of flight controls, but it could not compensate for the loss of thrust needed to keep the plane airborne.
The landing gear, which remained extended throughout the short flight, further illustrates the extent of the systems failure. Retraction of the gear relies on hydraulic power, which was compromised when the engines shut down. The combination of engine failure, RAT deployment, and extended landing gear left the aircraft in an unrecoverable state at such a low altitude.
Potential Theories: Why Were the Switches Turned Off?
The intentional nature of the fuel switch movement has led investigators and experts to explore several theories, with the most prominent being the possibility that one or both pilots deliberately acted to cause the crash. Below are the leading hypotheses:
1. Intentional Act by One or Both Pilots (Pilot Suicide)
Overview: The most alarming theory is that Captain Sabharwal, First Officer Kunder, or both intentionally turned off the fuel switches to end their lives, taking the aircraft and its passengers with them. This scenario echoes cases like Germanwings Flight 9525 (2015), where the co-pilot locked the captain out of the cockpit and crashed the plane into the Alps.
Evidence and Analysis: The deliberate movement of the switches, requiring specific mechanical effort, supports the idea of intent. However, unlike Germanwings, both pilots were present in the cockpit, and the CVR reveals a dialogue suggesting surprise or disagreement rather than premeditated collusion. If one pilot acted alone, the other’s response ("I didn’t") indicates they were not complicit. The timing—just seconds after takeoff—could suggest an impulsive decision rather than a planned act.
Motivation: Possible motives include personal crises (e.g., financial distress, relationship issues) or untreated mental health conditions like depression. However, no evidence of such factors has surfaced in the preliminary report, making this theory speculative at this stage.
2. Accidental Movement or Pilot Error
Overview: This theory posits that the switches were moved unintentionally due to a mistake or miscommunication during the high-pressure takeoff phase.
Evidence and Analysis: The design of the switches, with their locking mechanism and distinct operation, makes an accidental move highly unlikely. Mistaking the fuel switches for another control (e.g., thrust levers) is improbable given their location and the required action. The CVR’s exchange suggests one pilot believed the other acted, but the denial complicates this narrative.
Plausibility: While possible under extreme confusion or distraction, the deliberate sequence of movements weakens this theory.
3. Technical Malfunction
Overview: A mechanical or electrical fault might have caused the switches to move or the engines to fail independently of pilot action.
Evidence and Analysis: The AAIB report found no evidence of mechanical issues with the aircraft or engines. The fuel switches are mechanical, not electronic, and cannot be altered remotely or by a glitch. The engines began relighting when the switches were returned to "run," confirming their functionality and pointing to the switch movement as the sole cause of failure.
Plausibility: This theory is largely dismissed due to the mechanical nature of the switches and the lack of supporting evidence.
4. External Interference
Overview: A third party in the cockpit or external sabotage (e.g., hacking) could have caused the switches to move.
Evidence and Analysis: The report indicates only the two pilots were in the cockpit, and post-9/11 security protocols make unauthorized access unlikely. The mechanical switches rule out a cyber attack, as they require physical manipulation.
Plausibility: This scenario is improbable given the evidence.
5. Medical Emergency
Overview: A sudden medical event (e.g., heart attack, seizure) might have led a pilot to inadvertently move the switches.
Evidence and Analysis: The CVR shows both pilots communicating, suggesting no immediate incapacitation. A medical emergency causing precise switch movements is far-fetched without additional signs of distress.
Plausibility: This is considered unlikely.
Human Factors: The Role of Stress, Anxiety, and Fatigue
While the exact reason for the switch movement remains unclear, human factors are likely central to the investigation. Pilots operate in a high-stakes environment where stress, fatigue, and mental health can profoundly impact performance. Below are key factors that may have contributed to the incident:
1. Stress and Anxiety
Pilots face intense pressure from tight schedules, safety responsibilities, and personal challenges. Captain Sabharwal and First Officer Kunder, despite their experience, were not immune to stressors like financial difficulties, family issues, or workplace demands. Chronic stress can lead to impaired decision-making or, in extreme cases, irrational actions. If one pilot was overwhelmed, they might have acted impulsively, though no specific stressors have been identified.
2. Pressure and Bottling Up Emotions
The aviation culture often discourages pilots from openly discussing emotional struggles due to stigma or fear of losing their medical certification. Bottled-up emotions—whether from professional setbacks or personal turmoil—could manifest as sudden, uncharacteristic behavior. The lack of a clear motive in the CVR suggests any such breakdown would have been spontaneous rather than premeditated.
3. Jet Lag and Sleep Deprivation
Long-haul pilots frequently contend with irregular sleep patterns and jet lag, which can cause fatigue and cognitive decline. Even experienced pilots like Sabharwal and Kunder could have been affected by inadequate rest, slowing their reaction times or clouding their judgment. The preflight breath analyzer test confirmed no alcohol use, but fatigue assessments are less standardized and harder to detect.
4. Substance Use
While the pilots passed a breathalyzer test, the report does not mention screening for other substances (e.g., prescription drugs, sedatives, or illicit drugs). Substance use could impair perception or coordination, potentially leading to a catastrophic error. However, without toxicology results, this remains speculative.
5. Mental Health
Undiagnosed or untreated mental health issues, such as depression or anxiety disorders, could explain an intentional act. The aviation industry has made strides in addressing mental health, but barriers to seeking help persist. If either pilot was struggling silently, it might have influenced their actions in those critical seconds.
The Investigation and Next Steps
The AAIB, in collaboration with Boeing, General Electric, and international experts, continues to investigate the crash. The flight data recorder (FDR) and CVR will be analyzed in detail to reconstruct the pilots’ actions and the aircraft’s systems status. Fuel samples are being tested for contamination, though initial findings suggest no issues. The final report, expected within a year, will provide a conclusive determination.
Families of the victims are calling for transparency, including the release of CVR transcripts, but legal and privacy concerns may delay this. Air India and the authorities have pledged support to those affected and are committed to uncovering the truth.
A Tragedy Shrouded in Questions
The crash of Air India Flight 171 is a haunting reminder of the complexities of aviation safety. The fuel switches’ intentional movement to "cut-off" required deliberate effort, ruling out accidental causes and pointing to human action as the trigger. The engines were fully functional, and their failure stemmed solely from the loss of fuel, confirmed by the RAT’s deployment. Among the theories, the possibility of pilot suicide stands out as the most plausible yet troubling explanation, though the CVR’s ambiguity and lack of motive leave it unproven. Human factors—stress, fatigue, and mental health—likely played a role, highlighting the need for robust support systems in aviation.
As the investigation progresses, the aviation community awaits answers to prevent future tragedies. For now, Flight 171 remains a poignant mystery, underscoring that even advanced technology cannot fully mitigate the human element in flight safety.