The Aircraft Accident Investigation Bureau (AAIB) has released its preliminary report on the tragic crash of Air India flight AI171, a Boeing 787 Dreamliner, which crashed shortly after takeoff from Ahmedabad airport on June 12, en route to London Gatwick.
The report outlines key early findings from cockpit recordings, aircraft maintenance history, and safety compliance gaps, particularly with regard to a 2018 U.S. Federal Aviation Administration (FAA) advisory.
Here are the 10 key takeaways:
- No safety recommendations issued yet: At this stage, the AAIB has not issued any safety recommendations for Boeing 787-8 aircraft or GE GEnx-1B engine operators and manufacturers.
- Engine 1 showed signs of recovery: Engine 1’s core deceleration halted, reversed, and began progressing toward recovery after initial failure.
- Engine 2 failed to stabilise: Engine 2 relit but could not arrest core speed deceleration, despite repeated fuel reintroduction attempts.
- Fuel cutoff switches activated mid-flight: At 13:38:42 IST (08:08:42 UTC), the aircraft reached 180 knots IAS. Immediately after, both engines’ fuel cutoff switches moved from ‘Run’ to ‘Cutoff’.
- Attempted relight detected: Fuel switches for engines 1 and 2 were returned to ‘Run’ within seconds. EGTs for both engines rose, indicating relight efforts.
- Cockpit voice recording indicates confusion: One pilot asked, “Why did you cut off?” The other responded, “I did not do so,” suggesting possible miscommunication.
- Both engines dropped below idle speed: Engine and Aircraft Flight Recorder (EAFR) data confirmed that N2 values in both engines fell below minimum idle speed during the incident.
- Back flight recorder too damaged to get data: However, the aft Engine and Aircraft Flight Recorder (EAFR) was found to be substantially damaged in the incident and could not be downloaded using conventional methods, the AAIB said.
- Investigation will examine additional evidence: The AAIB said further evidence is being sought from stakeholders and will be reviewed in thenext phase of the probe.
- Flight data showed rising EGT during relight attempts: Engine and Aircraft Flight Recorder (EAFR) data showed a rise in Exhaust Gas Temperature (EGT) in both engines following the fuel switchback to ‘Run’, indicating combustion during relight attempts.
This accident is the first-ever fatal crash involving a Boeing 787 Dreamliner and one of the deadliest air disasters in Indian history, claiming 260 lives—241 passengers and crew, and 19 people on the ground. Only one passenger survived.
Cockpit Voice Recorder Reveals Fuel Cut Confusion
The 15-page preliminary report revealed a disturbing exchange between the pilots moments before the crash. The Cockpit Voice Recorder (CVR) captured one pilot asking, “Why was the fuel cut off?”—to which the other pilot responded he had not done so.
The AAIB has not confirmed the identity of the pilot who made the comment, nor who issued the final “Mayday” call, keeping key aspects of the final moments under wraps.
Missed 2018 FAA Advisory on Fuel Switch Mechanism
A significant revelation is that Air India failed to implement an FAA Special Airworthiness Information Bulletin (SAIB) issued in 2018, which recommended inspections of the fuel control switch locking mechanism on Boeing 787s. Since the FAA had not made it mandatory, Air India chose not to act on it, and no relevant inspections were conducted.
While this doesn’t amount to a regulatory violation, the AAIB said it may face further scrutiny in the final investigation report, especially since the fuel control switch appears to have played a role in the crash sequence.
Notably, the throttle control module was replaced twice—once in 2019 and again in 2023—but there were no reported defects linked to the fuel control mechanism after 2023.
Aircraft Was Airworthy and Recently Maintained
The Dreamliner was deemed technically airworthy at the time of the crash. Its Airworthiness Review Certificate (ARC) was valid from May 22, 2025, to May 23, 2026.
It had undergone L1-1 and L1-2 maintenance checks after 38,504 flight hours and 7,255 cycles, and its next scheduled D-Check—a deep structural inspection—was due in December 2025.
Both engines were also recently installed:
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Left engine: Installed on May 1, 2025
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Right engine: Installed on March 26, 2025
This significantly reduces the possibility that engine wear or mechanical failure caused the crash.
Wreckage Recovery and Secured Evidence
The AAIB confirmed that all wreckage was recovered, including drone-based documentation of the crash site. Both engines have been quarantined, and components of interest have been isolated for forensic examination.
The crash occurred when the aircraft struck the BJ Medical College hostel complex shortly after take-off. The investigation team has said there are no immediate recommendations for other Boeing 787-8 or GE GEnx-1B operators at this stage, but the inquiry is ongoing.
Statements from Air India and Boeing
Air India acknowledged the findings, expressing condolences and reiterating support for the affected families. The airline stated:
“We continue to mourn the loss and are fully committed to providing support… We acknowledge receipt of the AAIB’s preliminary report… and are cooperating fully with investigators.”
Boeing also issued a formal statement:
“Our thoughts remain with the loved ones of the passengers and crew… We continue to support the investigation and our customer.”
Both companies deferred technical commentary, citing the ongoing investigation under ICAO Annex 13 protocols.
What’s Next?
The AAIB has clarified that no final conclusions have been drawn yet. Investigators will continue to assess flight data, aircraft components, and human factors in the coming months. The final investigation report is expected within a year, which will likely determine accountability and outline systemic safety recommendations for both airlines and regulators.
