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

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.

The crash of an Air India 787-8 Dreamliner jet minutes after taking off on Thursday poses a major setback for Boeing, whose new CEO has been trying to rebuild trust following a series of safety and production challenges.