Investigators probing the June crash of Air India Flight 171, which killed 260 people, have uncovered a perplexing clue:

The preliminary probe report into the fatal crash of Air India flight AI171 indicated a chip malfunction as the cause, a former pilot told Reuters.

The 15-page report from the Aircraft Accident Investigation Bureau (AAIB), an office attached to the Ministry of Civil Aviation, has zeroed in on the most probable primary cause of the accident