Did the plane cut its own fuel? Investigators dig into system failures in Air India AI-171 crash: Report

The investigation is ongoing, and officials say the final report will focus on electrical and software system behavior, previous technical snags, and whether a chain of small failures led to a catastrophic loss of engine power.

Investigators probing the June 12 crash of Air India flight AI-171 are closely examining possible electrical and software faults that may have triggered un-commanded actions, including a sudden shift in fuel control switches to cut-off mode seconds after take-off.

An official aware of the investigation told The Indian Express that the probe is looking into whether a "system-triggered un-commanded transition" of the fuel switches might have occurred, causing the engines to shut down unexpectedly.

The Boeing 787-8 Dreamliner operating the Ahmedabad-to-London Gatwick flight crashed less than a minute after take-off, killing over 270 people.

Technical issues flagged hours before flight

Hours before the ill-fated flight, a pilot who flew the same aircraft from Delhi to Ahmedabad noted a ‘Stabiliser Position Transducer Defect’ in the aircraft’s technical log, the official told The Indian Express.

This transducer is a sensor that helps control the aircraft’s pitch by sending signals to the flight control system. While the issue was reportedly resolved per Boeing protocols, the official said: “The malfunction is a critical issue as it can trigger incorrect responses in flight control, including unintended fuel cut-off signal.”

Though the defect itself may not have caused the crash, investigators are now examining whether it contributed to multiple sensor failures that could have led to un-commanded engine shutdown.

Previous snags under the lens

The same aircraft had faced at least two major snags in the weeks and years leading up to the June 12 crash, the official told The Indian Express.

In December 2024, the same AI-171 flight was cancelled due to an 'unresolvable electric snag', and in 2015, the aircraft made an emergency landing following a Cabin Air Compressor (CAC) surge, a known issue in Dreamliners.

On December 12, 2024, Air India aborted boarding after a major electrical fault was detected. Though the issue was resolved the next day, the recurring nature of faults is now being investigated.

Cockpit recording hints at confusion

A preliminary report by the Aircraft Accident Investigation Bureau (AAIB), released on July 12, revealed a key cockpit exchange captured in the voice recorder.

“In the cockpit voice recording, one of the pilots is heard asking the other why did he cut-off. The other pilot responded that he did not do so,” the AAIB report said.

The investigators are now trying to determine whether the fuel switches were manually moved or if a system failure caused them to disengage.

Software bug or sensor failure?

Investigators are also examining whether a fault in the Full Authority Digital Engine Control (FADEC) system, the brain of the aircraft, caused a software bug that misread commands and initiated un-commanded actions.

“The probe is on to ascertain if the switch locks were disengaged due to an anomaly or if the FADEC’s Engine Control Unit malfunctioned,” the official told The Indian Express.

“We cannot overlook the possibility of a system error that resulted in the unexplained transition.”

The aircraft’s Flight Data Recorder, officials said, only captures electrical signals, not the physical position of gear or switches, which makes it harder to determine what exactly triggered the transition.

Last attempts to save the aircraft

As per the report, the aircraft took off and began to climb after reaching Vr speed when the sensors switched to the “air” mode. Within seconds, a loud bang was heard, the Ram Air Turbine (RAT) deployed, and the fuel control switches moved to the cut-off mode.

The crew tried to restart the engines mid-air.

“The pilots desperately attempted to cycle the fuel switch back to the run mode even as RAT began generating power… Unfortunately, with no safe altitude available, it could not be achieved,” the official said.

Past warnings, false alarms, and final moments

The Engine Indication and Crew Alerting System (EICAS) of the aircraft had flashed warnings on multiple recent flights. According to The Indian Express, technical logs showed at least two instances of false fuel system alerts in the three weeks before the crash.

A surviving passenger, Viswashkumar Ramesh, seated at 11A, told investigators that the aircraft stalled shortly after take-off, following a loud bang. He described flickering green and white lights and a feeling of the pilots 'giving race' to recover thrust before the crash.

According to the AAIB report, the aircraft had only reached 625 feet altitude, far lower than the 3,600–4,900 feet needed to attempt a safe Mayday landing using RAT-generated power.

No official responses yet

Queries sent by The Indian Express to the Director General of AAIB, the Directorate General of Civil Aviation (DGCA), and Air India have gone unanswered so far. Moneycontrol could not independently verify the report.

The investigation is ongoing, and officials say the final report will focus on electrical and software system behavior, previous technical snags, and whether a chain of small failures led to a catastrophic loss of engine power.