The worries surround the manufacturer’s 787 and 777 jets, which are in widespread use by the world’s airlines, including British Airways and Virgin Atlantic.
They follow issues with the single-aisle 737 Max, which most recently suffered a door plug blow-out during an Alaska Airlines flight in January.
The Washington-based Federal Aviation Administration (FAA) is now examining new claims from Boeing engineer Sam Salehpour, who said he had faced retaliation after identifying issues allegedly affecting the structural integrity of the airliners.
Salehpour claimed these arose after Boeing took shortcuts to speed up production of the 787. In his complaint to the FAA, he alleged Boeing’s engineering processes put stress on the 787’s fuselage joints.
Boeing told the BBC the claims were “inaccurate” and that the aircraft would “maintain its service life over several decades”.
Boeing is under intense scrutiny over issues relating to safety following the 737 Max incident, with chief executive David Calhoun due to stand down at the end of this year.
Earlier this week, the FAA launched another investigation into Boeing after an engine cowling fell off a different version of the 737 during take-off.
The aircraft was being operated by Southwest Airlines in the US. Similar episodes in the past have been blamed on airline maintenance staff failing to fasten the cowling.
