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 Boeing 787 Dreamliner was introduced as a game-changer in commercial aviation - an aircraft designed to be lighter, faster, and more fuel-efficient than anything before it.