Boeing announced that it has halted flight testing of the 777X after finding a failure in a structure on one of the wide-body aircraft.

The company said it discovered the damage to the custom part, which it said is located between the engine and the propeller, during scheduled maintenance. It has since grounded the other three aircraft in its test fleet.

Boeing grounds 777X test fleet after failure of key engine mounting structure https://t.co/7Ww9py0IkE (via @jonostrower) #staycurrent

— The Air Current (@theaircurrent) August 19, 2024

No other flight tests were scheduled for the other aircraft, Boeing said.

“Our team is replacing the component and recording any findings from the component and will resume flight testing when ready,” Boeing said in a statement.

The company has notified the U.S. Federal Aviation Administration and its customers, who have ordered 481 777X airplanes, according to Boeing’s website.

It was not immediately clear whether the fix and issue would affect the certification and delivery of the new wide-body aircraft, which are scheduled for 2025, about five years behind schedule.

Boeing began flight testing the aircraft with the Federal Aviation Administration in July, a major milestone.

The news comes as Boeing management, including new CEO Kelly Ortberg, are trying to overcome the company’s safety crisis that began with the door plug explosion earlier this year.