AI 171 crash anniversary: What engine tests could reveal as families await justice

On 12 June, 2025, thirty-two seconds after the Boeing Air India Flight AI171 lifted off, it came down on the hostel complex of BJ Medical College in Meghaninagar. 

It killed students flying back to universities in London, grandparents visiting children settled abroad, young couples, and two infants.  Only one passenger walked out of the wreckage. The other 241 people on board died, along with 19 on the ground. Sixty-seven more were injured. In barely half a minute, 260 families lost someone.

And there began a wait for answers that, one year later, has still not ended.

Air India crash final report likely to miss one-year deadline

Under international rules laid out in ICAO Annex 13, a final accident report is expected within 12 months, or an interim statement must be issued on each anniversary. 

That deadline arrives today and the final report is nowhere in sight, nor has a statement been issued.

The delay has now outlasted even a judicial deadline. On February 11, 2026, a Supreme Court bench headed by Chief Justice Surya Kant directed the AAIB to conclude its investigation and submit the final report within three weeks. That window closed in March.

On March 9, Civil Aviation Minister K Ram Mohan Naidu told the Rajya Sabha the report would be out “very soon.” Three months later, it has not been published. 

On April 1, the Supreme Court separately dismissed a PIL seeking disclosure of technical data underlying the AAIB’s preliminary report.

Where is the investigation stuck?

One of the major reasons for the delay, according to Reuters, is the detailed testing of the aircraft’s GE Aerospace GEnx engines in the United States, where specialised facilities are required.

Both engines are GE Aerospace GEnx-1B units and only GE’s own facilities in the US have the teardown rigs, test cells and metallurgical labs to dissect them properly. Bloomberg reports investigators are still examining evidence relating to the engines and their associated control systems, and the GEnx analysis remains incomplete, which is the proximate reason the final report has slipped.

What a physical teardown can reveal answers to two questions –

1 Were the engines healthy when the fuel stopped? 

Blade damage patterns, internal scoring and rotational signatures tell investigators whether the engines were spooling normally at impact or had already degraded. This either kills or revives the mechanical-failure theory, and if the cores show pre-existing damage, contamination, or distress that predates the cutoff, the story changes completely. 

2. Did the relight work? 

The preliminary report indicated the switches were moved back to RUN and a restart was attempted in the final seconds. The teardown can show how far each engine got in the relight sequence. It will be relevant to know whether anything could have saved the flight.

The AAIB’s preliminary report, released in July 2025, highlighted one extraordinary detail: both engine fuel control switches moved, one second apart, from “RUN” to “CUTOFF” just seconds after takeoff, starving both engines of fuel. The cockpit voice recording captured the confusion that followed one pilot asking why the fuel had been cut off, the other denying he had touched the switches. The report confirmed what happened, but not why, and the AAIB cautioned it was “too early to reach any definite conclusions.”

What the engine control unit data can reveal?

The EMU/FADEC (the computer that actually executes the fuel cutoff) keeps its own non-volatile memory, separate from the flight data recorder. The FDR tells you that a cutoff signal occurred; the engine control unit’s memory can potentially tell you where the command originated and whether the electrical signal path is consistent with a physical hand moving the switches. 

That’s why investigators travelled to France to examine the engine management unit data as a part of the GEnx engine-control supply chain is based there.

In other words: the engine tests are the arbiter between all three competing theories. Human action, mechanical defect, and software fault each leave a different electronic and metallurgical fingerprint, and this is the only evidence that can distinguish them. It’s also why the pilots’ union is so insistent that nothing more be published until this analysis is done — the FIP maintains the aircraft had a “plethora of problems” including possible electrical failure, and argues the engine and systems examination now underway could determine why the flight lost thrust. 

What Air India and Boeing have said 

Air India, now under the Tata Group, has said it is fully cooperating with the investigation. The airline has maintained that early findings do not show any fault in its operating practices, and one statement even said there was “nothing wrong” with how operations were being carried out. The airline has since also focused on supporting families affected by the crash while waiting for the final findings before making any major operational changes. 

Air India’s outgoing CEO Campbell Wilson publicly committed to full cooperation and support for victims’ families. 

The airline also temporarily cancelled 15% of its long-haul flights. In 2026, Air India announced further cancellations of hundreds of international flights between June and August, citing fuel costs, airspace disruptions, fleet shortages, and ongoing regulatory pressure. 

The airline has continued its restructuring and fleet modernisation under Tata ownership, even as pressure increased after the crash. Wilson later stepped down amid challenges facing the carrier. 

For Boeing, this was a major shock. It was the first fatal hull loss of a 787 Dreamliner since the aircraft entered service, a model that had maintained a strong safety record until then. The investigation could lead to stricter regulations, higher compliance costs, and possible design or operational changes if faults are confirmed. 

Boeing has also been assisting investigators. The company has followed standard procedure by not making detailed public comments while the investigation is still active. So far, there has been no fleet-wide grounding of the Boeing 787 based on the preliminary findings. 

Boeing, along with Indian and US aviation authorities and engine maker GE Aerospace, remains part of the ongoing investigation. 

Families of victims have filed lawsuits in Delaware, USA, against Boeing and Honeywell. Separate legal cases have also been filed in the UK, where many of the victims were British nationals. Some legal representatives say Air India has offered additional compensation in exchange for families signing agreements that waive their right to pursue further legal action.

How the past year has unfolded 

For Air India, the crash came during an already difficult turnaround phase under Tata Group ownership. The airline has faced heavy financial stress, operational disruptions, and scrutiny. Reports have pointed to large annual losses in FY26, influenced by multiple factors, including the crash, fuel costs, and airspace challenges.