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.

An Air India Boeing 787, the same kind of plane that crashed 4 days earlier, was forced to turn around after a midair "technical issue," the airline says.

Air India has cancelled eight international Boeing 787-8 Dreamliner flights after the horrific aviation disaster last week. The passenger jets were hit by a mix of issues from aircraft unavailability, technical snags, airspace restrictions, and extended safety checks.