Inside the Preliminary report: Exploring AI 171

One month after the tragic accident that took 260 lives, the Aircraft Accident Investigation Bureau has released the official Preliminary report detailing the initial findings of the investigation.

In case you missed it, on 12 June 2025, Air India Flight AI171, operated by a Boeing 787-8 registered as VT-ANB, was involved in a shocking accident shortly after taking off from Sardar Vallabhbhai Patel International Airport (VAAH) in Ahmedabad. The aircraft was on a scheduled international flight to London Gatwick (EGKK) when it crashed about 0.9 nautical miles from the departure end of Runway 23. This incident resulted in 260 deaths, including all 242 people on board and 18 others on the ground.

Overview of events

Aircraft and Weather

The accident involved an Air India-operated Boeing 787-8 Dreamliner, registration VT-ANB (serial number 36279), manufactured in 2013 and powered by GEnx-1B70/P2 engines. The aircraft was conducting a scheduled international passenger flight with 230 passengers, 10 cabin crew, and 2 pilots on board when it crashed during the initial climb from Ahmedabad on 12 June 2025 at 0809 UTC (13:39 IST). Weather conditions at the time were visual meteorological conditions (VMC), with light winds (240–260° at 3–7 knots), 6000 meters visibility, and no significant weather reported.

Crew Information

The flight was operated by an experienced crew. The Captain was 56 years old, an ATPL holder with 15,638 hours total flight time, 8,596 hours on type (B787) and 8,260 as PIC on type.

The First Officer was 32 years old, a CPL holder with 3,403 hours total and 1,128 hours on type. He was the Pilot Flying for that sector.

Both pilots were medically fit and had adequate rest prior to the flight.

Pre-flight

The aircraft had arrived in Ahmedabad earlier that morning as AI423 from Delhi. A minor technical discrepancy ("STAB POS XDCR" message corresponding to Stabilizer Position Transducer) was reported and addressed by maintenance personnel. The aircraft was subsequently released for service.

At the time of the accident, five deferred MEL items were active, none of which related to powerplant or primary flight control systems. All applicable Airworthiness Directives (ADs) and service bulletins were reportedly complied with.

Timeline of the Accident flight

According to the AAIB’s analysis of ATC data, Enhanced Airborne Flight Recorder (EAFR) data, and airport surveillance:

08:07:33 UTC: Aircraft cleared for takeoff from Runway 23.
08:08:35 UTC: Aircraft achieved Vr (155 knots) and commenced rotation.
08:08:39 UTC: Aircraft air/ground sensors transitioned to airborne mode.
08:08:42 UTC: At approximately 180 knots indicated airspeed, the maximum achieved by the aircraft, both engine fuel control switches moved from RUN to CUTOFF, one after the other, separated by one second. The Engines’ N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off. In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.
08:08:47 UTC: Ram Air Turbine (RAT) hydraulic pump began supplying hydraulic power.
08:08:52 UTC: Engine 1 fuel control switch moved back to RUN.
08:08:56 UTC: Engine 2 fuel control switch moved back to RUN.
08:09:05 UTC: “MAYDAY” call transmitted.
08:09:11 UTC: Flight data recording ceased. Aircraft impacted buildings in the BJ Medical College hostel complex.

CCTV footage confirmed RAT deployment shortly after liftoff. No bird activity or foreign object damage was reported.

Report or a Cover up?

This report is expertly written not to inform, but to confuse the public. And in doing so, it conveniently clears Boeing and GE of any accountability.

If the report came out and directly stated this was a case of pilot suicide or murder, public outrage would explode. So instead, it hides behind vague language like “one pilot asked another”. No “Captain” or “First Officer”, just ambiguity. That’s not standard. Any other crash reports would mention conversations quoted as is from the Cockpit but this one tries to infer and hide it rather than present the cold, hard truth.

Veteran pilots and aviation professionals are calling it out: this report looks like a calculated move to shift blame onto the pilots and protect the corporates.

Source: EASA Safety Publication.

The preliminary investigation references Special Airworthiness Information Bulletin (SAIB) NM-18-33, issued by the Federal Aviation Administration (FAA) on 17 December 2018. This bulletin was published in response to operator reports involving Boeing 737 aircraft, where fuel control switches were found installed with their locking mechanisms disengaged, potentially allowing unintended movement. Although the issue was not classified as an unsafe condition that warranted an Airworthiness Directive (AD), the FAA issued the SAIB to raise awareness and recommend inspections. The design and locking mechanism of the fuel control switch part number 4TL837-3D, cited in the bulletin, is also used in the Boeing 787-8 model, including the accident aircraft VT-ANB.

The SAIB clearly states the dangers of not fitting the locking mechanism to the fuel control switches. Source : EASA Safety Publication.

According to the preliminary report, Air India did not perform the recommended inspections outlined in the SAIB, as compliance was not mandatory. Furthermore, while the aircraft’s throttle control module had been replaced in 2019 and again in 2023, no defects linked specifically to the fuel control switches were reported. The AAIB has not yet determined whether the potential disengagement of the locking feature contributed to the dual engine shutdown; however, the inclusion of this bulletin in the report suggests that cockpit design and mechanical safeguards may become key areas of focus in the final analysis.

Final Thoughts

The AI171 preliminary report provides a detailed sequence of events but leaves the central question unresolved: what caused both fuel control switches to move to cutoff immediately after takeoff? With no mechanical defects reported, no bird ingestion, and no significant weather factors, the investigation now pivots toward cockpit interface design, human factors, and possible system vulnerabilities.

While the crew attempted an inflight engine relight under extremely limited time and altitude, the aircraft ultimately descended uncontrollably, leading to a high-fatality ground impact. The event underscores the critical importance of secure and fail-safe design around essential flight controls, particularly those with catastrophic potential if inadvertently activated.

Until the final report is published, operators and training departments would be well advised to revisit cockpit procedures, the designs of high-consequence switches, and awareness of non-mandatory bulletins that, while advisory, may carry operational significance.

The accident of AI171 is a sobering reminder that even in highly automated and modern aircraft, small design oversights or momentary actions can trigger outcomes far beyond recovery.

Thumbnail credit: Wolfgang Kaiser