The investigation report says Air India did not carry out those inspections - prompting speculation that the accident could have been caused by faulty switches being flipped by accident. However, in an internal note seen by the BBC, the FAA has since reiterated its belief that the issue did not compromise safety.

Aviation expert Sanjay Lazar on Sunday said that the preliminary report by the Aircraft Accident Investigation Bureau (AAIB) on the Air India flight 171 crash raises more questions than answers, and expressed that the investigative authority should have made the transcript of cockpit voice recorder (CVR) public.