On 30 July 2026, India's government told Parliament something that, more than a year after the Air India 171 disaster, only makes the central mystery harder to solve: the Boeing 787's fuel control switches — the very components at the heart of the investigation — show no defect.

The finding matters because those two small switches are, so far, the only thing investigators know went wrong. On 12 June 2025, Air India flight AI171, a Boeing 787-8 registered VT-ANB, lifted off from Ahmedabad bound for London Gatwick and crashed roughly 32 seconds later into a medical-college hostel about 1.7 kilometres beyond the runway. Of the 242 people on board, 241 died; another 19 were killed on the ground. A single passenger survived.

The preliminary report established that, seconds after lift-off, both engine fuel control switches moved from RUN to CUTOFF, one after the other, starving both engines of fuel. Why they moved has never been explained. The latest testing rules out one answer — a faulty switch — without supplying another.

What the government said

Speaking to Parliament, Deputy Civil Aviation Minister Murlidhar Mohol said that a detailed examination of the fuel control switch — including the structural integrity of its locking detents, the small catches meant to stop the switch being knocked out of position — had found no defect. The wider thrust control module, he added, is still being analysed at a Boeing facility, and investigators have not yet concluded why the switches moved.

How the investigation reached this point

The AAIB's preliminary report, published in July 2025, laid out the sequence in stark terms. Within a second of each other, both fuel control switches transitioned from RUN to CUTOFF just after the aircraft left the ground. The switches were later returned to RUN, and the engines attempted to relight — but the aircraft was too low and too slow, and at least one engine could not recover thrust in time.

The cockpit voice recording captured a brief, haunting exchange: one pilot asked the other why he had moved the switches to cutoff; the other replied that he had not. The report stopped there. It did not establish why the switches moved, and it assigned blame to no one.

The locking-feature question

There is a reason the locking detents are being scrutinised. Back in 2018, the U.S. Federal Aviation Administration issued an advisory bulletin flagging that the fuel-cutoff switch locking feature could, on some Boeing models including the 787-8, be installed in a way that left it disengaged. The bulletin was advisory rather than mandatory, and the recommended inspection was, by Air India's own account to investigators, not carried out on the accident aircraft.

That history is exactly why the July 2026 finding is significant. If the switch and its locking mechanism are sound, the "the switch simply slipped" explanation becomes harder to sustain — which pushes the inquiry deeper into the electronics and logic of the thrust control module now sitting on a bench at Boeing.

A careful, contested inquiry

Investigators have broadly split into two readings. One looks for a technical trigger — an electrical fault that could have disturbed the aircraft's systems, with the switch movements a symptom rather than a deliberate act. The other reads the cockpit audio as evidence of a manual shutdown. No cause has been established, and Indian courts have been careful to stress that the preliminary report does not imply culpability on the part of the pilot-in-command.

More than a year on, the families are still waiting for the one thing the investigation cannot yet give them: a reason. The thrust control module now being examined at Boeing may hold it. Until then, the most honest summary is the uncomfortable one — the switches moved, and nobody has yet proven how.

Sources: FlightGlobal; BusinessToday; The Air Current; Airways Magazine; Al Jazeera; Britannica.