The preliminary finding gives investigators a new line of inquiry as they study a crash that killed all but one of the plane’s passengers.

The crash of an Air India Boeing 787 Dreamliner seconds after takeoff from Ahmedabad city, killing all but one of the 242 people on board, is the world's worst aviation disaster in a decade.

One of the engines of the Air India plane that crashed last week was new, while the other was not due for servicing until December, the airline's chairman has said. In an interview with an Indian news channel, N Chandrasekaran said that both engines of the aircraft had "clean" histories.