Captain Kishore Chinta, a former investigator with India's Aircraft Accident Investigation Bureau (AAIB), calls this "the rarest of the rare" crashes - a controlled flight into terrain just 30 seconds after take-off. "To my knowledge, nothing quite like this has ever happened," he told the BBC.

Investigators in India are studying the black boxes of a Boeing 787 Dreamliner after recovering them from the aircraft wreckage to ascertain the cause of last week’s plane crash that left at least 270 people dead.

Since the Tata takeover, India’s Directorate General of Civil Aviation has repeatedly fined Air India over safety and other regulatory violations, including an Rs8mn ($95,000) penalty last year for exceeding flight duty time limits. At home, it is competing in a near-duopoly with IndiGo, which has been boosting its international long-haul routes.