“Why did you cut off?”

“I didn’t.”

This was the exchange between the two pilots on the Air India flight after both engines of the Boeing 787-8 Dreamliner inexplicably shut down, causing the aircraft to crash seconds after take-off, a preliminary report found.

The London-bound Flight AI171 crashed in Ahmedabad on the morning of June 12, killing at least 260 people, including the 241 passengers and crew on board.

This cockpit voice recording, retrieved from the wreckage, is part of the preliminary investigation report by India’s Aircraft Accident Investigation Bureau (AAIB). Newsaundry went through the report to piece together important details.

What unfolded after takeoff

According to the flight data recorder, the plane reached takeoff decision speed – known as V1, which was 153 knots (about 283 km/h) – at 1:38:33 pm IST. This is the point where the pilots must commit to take off; after this speed, it’s no longer safe to abort.

Two seconds later, the aircraft reached Vr or rotation speed when the pilot began to lift the nose of the plane off the ground. By 1:38:39 pm, the aircraft was fully airborne and quickly accelerated to 180 knots, or a speed of 333 km/hr.

Then, something inexplicable happened. Both engines almost simultaneously shut down.

The fuel cutoff switches for Engine 1 and Engine 2 moved from “RUN” to “CUTOFF” within one second of each other, causing a rapid drop in both engines’ core speeds (N1 – speed of the front fan, and N2 – speed of the compressors and turbine).

In the cockpit voice recorder, one pilot is heard asking the other, “Why did you cut off?” The other pilot replied that he did not do so.

On an aircraft, each engine has a fuel switch that controls whether fuel is going to the engine or not. If the switch is moved from "RUN" (fuel on) to "CUTOFF" (fuel off), the engine will shut down.

This is a very serious situation, especially right after takeoff, when the plane needs full power from both engines to climb safely into the sky. The Boeing 787 only has two engines, so losing even one is a big deal. Losing both is catastrophic.

Pilots are never supposed to turn off the fuel switch during takeoff. That’s the moment when engines are working their hardest, and shutting them off would cause the plane to lose power and possibly crash.

The switches can only be turned off manually – it requires a clear, deliberate action. It’s not something that can happen accidentally with a bump or by brushing against it. Pilots are trained to only shut off the engine this way if there’s a serious emergency, like an engine fire or major damage to the plane. Even then, they follow strict emergency procedures, and both pilots must agree on the action.

If fuel is shut off right after takeoff, it can lead to:

• Imbalance in engine power, making the plane hard to control,

• A dangerous drop in altitude, or

• The plane being unable to climb safely, especially when it’s heavy with passengers and fuel.

To prevent mistakes, the Boeing 787’s fuel switches are protected by a safety system, like a digital lock, so they can’t be turned off by accident. These switches are only meant to be used in emergencies, and only after going through proper safety checks.

With both engines losing power, the aircraft began to lose altitude before it could clear the airport perimeter wall. CCTV footage from the airport showed the Ram Air Turbine (RAT) deploying immediately after lift-off – an emergency measure that indicates total power loss – and no significant bird activity was observed in the vicinity of the flight path.

At 13:38:52 IST, the crew attempted to recover – Engine 1’s cutoff switch was flipped back to RUN. Two seconds later, Engine 2’s switch followed. The APU (auxiliary power unit) also began to activate.

Both engines began a relight sequence, as managed by the aircraft’s FADEC system. Engine 1 started to recover. Engine 2, however, kept losing speed despite repeated ignition and fuel inputs.

The last EAFR recording ends at 13:39:11 IST. Just seconds earlier, one of the pilots had issued a frantic “MAYDAY” call. There was no further communication. Air Traffic Control saw the aircraft crash outside the airport boundary and activated emergency response at 1.44 pm.

Aircraft history and maintenance

The Directorate General of Civil Aviation (DGCA) issued the airworthiness certificate, confirming that an aircraft is safe for flight, for the flight on May 22, 2025, and it was valid till May 23, 2026.  

The left engine had been installed on May 1, 2025, and the right one in March 2025. As of the crash date, the aircraft had five active Minimum Equipment List (MEL) items – four Category C and one Category A – but all were within their valid limits. None of these were linked to engine functionality.

Interestingly, Boeing had earlier flagged concerns over the fuel control switch’s locking mechanism in a 2018 Safety Bulletin (SAIB NM-18-33). The bulletin, based on issues found in Boeing 737s, highlighted that fuel control switches could be installed without engaging the lock. The 787 uses a similar switch. However, the bulletin was advisory, not mandatory, and Air India did not conduct the recommended inspections.

VT-ANB’s throttle control module, which pilots use to modulate engine thrust via electronic signals, had been replaced in 2019 and 2023, but not due to any fuel switch-related defect. Since 2023, no issues have been reported with the switch.

Investigation so far

As per the preliminary investigation report, all wreckage site activities, including drone photography and videography, have been completed. The wreckage has since been moved to a secure area near the Ahmedabad airport.

Both engines were retrieved from the crash site and quarantined at a hangar within the airport premises. Investigators have identified and isolated several components of interest for further technical examination. Fuel samples collected from the bowsers and tanks used to refuel the aircraft were tested at the DGCA’s laboratory and found to be satisfactory. However, only a very limited quantity of fuel could be retrieved from the APU filter and the refuel/jettison valve of the left wing. These samples will be sent to a suitable testing facility capable of analyzing such small quantities.

Data from the aircraft’s forward Enhanced Airborne Flight Recorder (EAFR) has been downloaded and is currently under detailed analysis. Statements from eyewitnesses and the surviving passenger have been recorded. A complete analysis of postmortem reports of the crew and passengers is also underway to match aeromedical findings with engineering observations. 

Investigators continue to gather additional information based on initial leads. At this stage, no specific safety recommendations have been issued for B787-8 aircraft or GE GEnx-1B engines.

The investigation remains ongoing, with the team reviewing and examining further evidence, records, and information from various stakeholders.

While many questions remain, the preliminary report confirms one key fact that both engines shut down mid-air for reasons still unclear. Whether this was due to a technical glitch, human error, or a design flaw remains to be determined.

What happened on June 12?

On June 12, 2025, an Air India Boeing 787-8 aircraft, with the registration number VT-ANB, landed at Ahmedabad airport. It had flown in from Delhi as flight AI423 and touched down at 11:17 am. The plane was then parked at its designated spot (called bay 34).

The pilots of this incoming flight wrote a note called a Pilot Defect Report (PDR) in the plane’s Tech Log (a technical logbook) about a warning called “STAB POS XDCR”. This warning means there might be a problem with a small sensor called the Stabilizer Position Transducer – a device that checks the position of the plane’s tail part (stabiliser), which helps keep the aircraft level in flight.

An on-duty Aircraft Maintenance Engineer checked the issue using a special guide called the Fault Isolation Manual (FIM). After fixing the problem, the engineer cleared the plane for its next flight at 12:10 pm.

This next flight was AI171, flying from Ahmedabad to Gatwick Airport in London. The planned departure time was 1:10 pm.

The two pilots on the flight included a pilot in command (PIC) who had an Airline Transport Pilot Licence (ATPL) – the highest licence for airline pilots, and a co-pilot with a commercial pilot licence (CPL).

Both pilots were based in Mumbai and had arrived in Ahmedabad the day before. They had enough rest before this flight. For this flight, the co-pilot was the Pilot Flying (the one handling the controls), while the PIC was the Pilot Monitoring (supervising and assisting). They were supported by 10 cabin crew members. 

On board were 230 passengers: 15 in business class, 215 in economy class, plus two babies. No hazardous cargo was carried. The plane had 54,200 kg of fuel, and its total weight at takeoff (213,401 kg) was within the allowed limit (maximum allowed was 218,183 kg).

Before the flight, both pilots passed mandatory alcohol tests and were seen at the boarding gate around 12:35 pm. The plane started moving back from its parking spot (pushback) at 1:18 pm, taxied to the runway, and got permission to take off at 1:37 pm.

How the investigation started

On the same day (June 12), the AAIB was told that the plane had crashed shortly after takeoff from Ahmedabad while on its way to Gatwick. The alert came from the Airport Authority of India and the airline.

A five-member AAIB team, including the Director General, reached Ahmedabad that day. Three more officers from the DGCA joined them from Mumbai to help with the on-site probe.

Since the plane was made in the United States, the National Transportation Safety Board (NTSB) – the US agency for investigating plane accidents – was informed, as required by international aviation rules (ICAO Annex 13). Passengers on board were also from the UK, Portugal, and Canada, so those countries’ investigation agencies – AAIB-UK, GPIAAF-Portugal, and TSB-Canada – were notified too.

The NTSB sent a representative with experts from Boeing, GE (the engine maker), and the US aviation regulator, the Federal Aviation Administration, to help. They arrived in Ahmedabad on June 15, 2025. Officials from the UK’s AAIB also came to the site and met with India’s AAIB chief.

According to India’s Aircraft Investigation Rules, 2017, a formal investigation team was formed. Sanjay Kumar Singh was named the investigator-in-charge, and Jasbir Singh Larhga was made the chief investigator. Other members were Vipin Venu Varakoth, Veeraragavan K, and Vaishnav Vijayakumar.

A support team of subject matter experts was also set up. This team included experienced pilots, aircraft engineers, aviation doctors and psychologists, and experts in reading data from the plane’s Flight Data Recorder (the “black box”).

Newslaundry had extensively reported on the aftermath of the flight crash, eyewitness accounts, how everyday lives were cut short in an instant, the despair of victims' families, and the casualties who weren’t passengers. You can read our reports here.    

In times of misinformation, you need news you can trust. We’ve got you covered. Subscribe to Newslaundry and power our work.