The Aircraft Accident Investigation Bureau (AAIB) of India has officially released the preliminary report on the tragic crash of Air India Flight AI171 involving a Boeing 787-8 Dreamliner, registration VT-ANB.
On June 12, 2025, an Air India Boeing 787-8 (registration VT-ANB) operating as Flight AI171 from Ahmedabad to London Gatwick crashed just after takeoff, killing all 241 onboard and 19 on the ground. What happened in the next 30 seconds after rotation has stunned even the most seasoned professionals.
This was no stall, no bird strike, and no bad weather. This was a dual engine flameout right after liftoff — triggered by both fuel control switches moving to CUTOFF.
🚨 Sequence of Events: Takeoff to Tragedy in 32 Seconds
08:08:39 UTC: Aircraft lifts off Runway 23 at VR (155 knots).
08:08:42: Max recorded IAS: 180 knots.
08:08:43–44: Engine 1 and 2 fuel control switches transition to CUTOFF, one second apart.
08:08:47: Ram Air Turbine (RAT) deploys. Full electrical loss confirmed.
08:08:52: Fuel switches moved back to RUN. APU begins auto-start.
08:08:56: Engines begin relight sequence.
08:09:05: “Mayday, Mayday, Mayday” transmitted.
08:09:11: All flight recorder data ends.
Impact: Approx. 0.9 NM from runway — BJ Medical College hostel.
✈️ Aircraft and Systems Snapshot
Aircraft: Boeing 787-8 | MSN 36279 | Built: 2013
Total Time: 41,868 hours
Engines: GEnx-1B70/P2 | Installed: March & May 2025
Fuel Onboard: 54,200 kg | TOW: 213,401 kg (within limits)
Flap Setting: 5° confirmed
Gear: Down
Thrust Levers: Found in idle, but EAFR confirms TOGA thrust until impact
MELs: 4 CAT C (non-critical), 1 CAT A for nitrogen system
🔍 What Could Trigger Dual Fuel Cutoff?
This is the million-dollar question — and the investigation is still digging.
Here’s what’s known:
The fuel control switches (P/N 4TL837-3D) are spring-loaded and protected by a locking mechanism.
A 2018 FAA SAIB (NM-18-33) flagged the possibility that some switches could be installed without the locking feature engaged.
Air India did not conduct inspections, citing the non-mandatory status of the SAIB.
Throttle control modules had been replaced twice (2019, 2023), but not due to fuel switch issues.
No recorded defects involving switches since 2023.
If there was a design issue or mechanical disengagement of the locks, it might have made accidental or spurious activation possible — especially during turbulence or unintended contact.
👨✈️ Crew Profile
The flight was crewed by two well-qualified pilots. The Captain, aged 56, was acting as Pilot Monitoring (PM) and held an ATPL with a total flying experience of 15,638 hours, including 8,596 hours on the Boeing 787. The Co-Pilot, aged 32, was the Pilot Flying (PF) with a total of 3,403 hours, of which 1,128 hours were on type. Both pilots had reported for duty well-rested, were medically fit, and had no history of fatigue, substance use, or psychological stress reported prior to the flight..
🔥 Wreckage & RAT Deployment
✅RAT deployed instantly, confirming total engine-driven power loss.
✅Engines separated from fuselage after impacting hostel buildings.
✅EAFR (Enhanced Airborne Flight Recorder) forward unit was recovered and partially readable.
✅Cockpit voice audio was recovered, including the full accident sequence.
Interestingly, the APU started successfully as per auto-start logic — but by then, time and altitude had run out.
🧪 Current Investigation Focus
🔎Fuel switch design: Was there a failure in the mechanical lock?
🔎Cockpit ergonomics: Could a hand motion or unintended force disengage switches?
🔎Electrical misfire or system signal? Any EICAS anomalies?
🔎Human error? Pilot mistake under pressure — but why would both switches be moved?
🔎Sabotage or external influence? No current evidence of foul play.
Note: No safety bulletins have yet been issued by the AAIB or DGCA, but scrutiny over the fuel switch installation process and Boeing’s 787 cockpit ergonomics is expected to rise.
💬 Final Thoughts for the Aviation Community
To the casual observer, this crash may appear inexplicable. But to those of us in the industry — pilots, technicians, engineers — it is a stark reminder that failure isn’t always systemic or visible. Sometimes, it’s one overlooked advisory, one flawed design assumption, or one unpredictable sequence of human-machine interaction.
Whatever the final cause, the loss of VT-ANB will likely influence how fuel systems and cockpit switch safeguards are designed, inspected, and trained for — especially in the high-stakes takeoff phase.
We’ll be watching closely as the final report unfolds.
🛫 Fly smart. Fly safe. Even in a world of high automation, your sharp eyes and procedural discipline are irreplaceable.
📌 Stay tuned to Aviation2Day for updates on the VT-ANB final investigation report.
Source:
AAIB Preliminary Report on Air india Accident
SAIB NM-18-33
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