Air India and Boeing are in the midst of significant turnarounds, but knowing the cause of the crash of Flight 171 will take a lengthy investigation.

Last year, the F.A.A. said it was also investigating claims by a Boeing engineer that parts of the fuselage, or body, of the Dreamliner were improperly fastened together, which the whistle-blower said could cause premature damage to the plane over years of use.

An Air India crash Thursday involved a Boeing 787-8 Dreamliner, which the aircraft manufacturer first delivered 14 years ago.

The Air India flight, carrying 242 passengers and crew members, crashed shortly after takeoff from Ahmedabad, India, en route to London Gatwick.

It’s also the latest disaster to hit the beleaguered American aerospace giant — which has been dogged by a door that blew off a 737 jet, a leaky spacecraft that stranded astronauts on the International Space Station for months, as well as politically damaging delays in outfitting the new Air Force One jets.

The crash happened just weeks after the company cut a deal with the U.S. government to avoid taking criminal responsibility for a pair of deadly crashes in 2018 and 2019.

The investigation into Air India flight 171 crash opens up questions into the many concerns surrounding Boeing's 787.