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

An Air India Ltd. plane crash that killed 241 of the 242 people on board shortly after takeoff from Ahmedabad on June 12 was the worst commercial airline disaster since 2014. It also marks the first time that the widely used Boeing Co.

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.