Key to mystery: 32 seconds in flight deck

In the final seconds of Air India Flight 171, as both engines lost power and the Boeing 787 began its fatal descent, a crucial exchange unfolded between two experienced pilots that investigators believe holds the key to understanding what went wrong.

- Neha LM Tripathi

"One of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so," according to the Aircraft Accident Investigation Bureau's preliminary report. Those paraphrased words are at the centre of a complex investigation into whether the accident was caused by human error, mechanical failure, or an emergency procedure gone catastrophically wrong.

The cockpit was staffed according to standard procedures: first officer Clive Kunder, 32, served as pilot flying with captain Sumeet Sabharwal, 56, monitoring. Both had passed pre-flight breath analyser tests and met all rest requirements, the report noted.

Kunder, the junior pilot, had 1,128 hours on the Boeing 787 and was responsible for controlling the aircraft during the critical takeoff phase. Sabharwal, with 8,596 hours on the same type of jet, was tasked with monitoring systems and providing oversight-a standard arrangement designed to combine experience with operational currency.

JS Rawat, former joint director general of DGCA, cautioned against drawing conclusions from the limited cockpit voice recorder information. "While nothing can be ascertained with a paraphrased sentence in the report that mentions one pilot asking the other if he switched off the fuel switches and the second pilot denying the same, nothing can be positively said at this stage," he said.