Boeing has suspended load testing of its 777X aircraft after a reported cargo door failure, dealing another blow to the widebody programme’s timeline.

The airframer says the “issue” took place during the final load testing of the 777X static test aircraft.

While Boeing gave no indication what the incident was, The Seattle Times — which first reported the news — stated that a cargo door had exploded outwards during the test on Thursday.

Boeing states: “The testing conditions were well beyond any load expected in commercial service.” It stressed that the test team “followed all safety protocols” and are now working to understand the root cause.

It is unclear when load testing on the 777X will resume, but Reuters has quoted Boeing spokesman Paul Bergman as saying that “overall testing is continuing”.

The incident is the latest in a string of issues plaguing the widebody programme. In mid-August, Boeing stated that development of the ultra-long-range 777-8 will be put on hold, after a review of development schedules and customer needs.

The 777-8 is the smaller, longer-range follow-on to the 777-9, which is designed to carry 384 passengers in a two-class configuration and fly up to 16,170km.

Weeks earlier, Boeing pushed back the 777-9’s first flight because of an issue with the General Electric GE9X engines that power both 777X variants.

Cirium’s fleets data indicates that are currently 334 orders for the 777X programme.