Man made error or malfunction? AAIB report on Ahmedabad plane crash gives no conclusive reasons

The preliminary investigation report on the Air India Flight 171 crash, which claimed 260 lives in June, has revealed confusion between the two pilots in the cockpit and raised questions as to why the fuel-control switches were flipped mid-flight.

As per the report released by the Aircraft Accident Investigation Bureau (AAIB), moments before the plane crashed, both engine fuel cutoff switches were nearly simultaneously flipped, starving the engines of power. The report has ruled out initial theories around bird hit and fuel contamination.

According to the 15-page report, the aircraft’s fuel switches inexplicably transitioned from the “RUN” to the “CUTOFF” position just after takeoff. This critical change caused the engines to lose power, leading to the crash. The cockpit voice recorder captured one of the pilots asking the other, "Why did you cut off the fuel?" The other responded, "I did not do so."

However, the report does not specify which pilot made each statement, nor who sent out the distress call, “Mayday, Mayday, Mayday,” moments before impact.

The commanding pilot, Captain Sumeet Sabharwal, 56, was a senior Air India instructor with 15,638 hours of flying experience. His co-pilot, Clive Kunder, 32, had logged 3,403 flying hours.

The report makes no mention of any accountability on the part of aircraft manufacturer Boeing or engine maker GE. The initial reports had speculated that poor aircraft maintenance might have contributed to the crash, but the AAIB’s report does not confirm this.

The investigation agency also noted that no significant bird activity was observed near the flight path at the time of the incident. The aircraft began descending before it crossed the airport’s perimeter wall.

The report stops short of drawing conclusions but raises critical questions about the circumstances that led to the uncommanded shift of the fuel control switches. The full investigation is still underway, and the AAIB is expected to issue a final report in the coming months. A BBC report says that lever-lock fuel switches are designed to prevent accidental activation, and they need to be pulled up to unlock before they can be flipped. Besides, there are guard brackets which shield the switches from accidental bumps, according to the BBC article. 

(With inputs from Reuters)