08:19 AM EDT, 08/20/2024 (MT Newswires) -- (Updates the first, fourth and fifth paragraphs with Boeing's ( BA ) statement.)

Boeing ( BA ) said Tuesday that it is grounding its 777X test fleet after finding cracks in an engine mounting structure.

The issue was discovered on one of the test aircraft after completing a more than five-hour flight from Hawaii on Friday, The Air Current reported, citing people familiar with the matter. Another two 777Xs were similarly affected.

Boeing ( BA ) began flight-certification testing for the 777X last month. Delivery for the new jetliners are slated for 2025.

"During scheduled maintenance, we identified a component that did not perform as designed," Boeing ( BA ) told MT Newswires in an emailed statement. "Our team is replacing the part and capturing any learnings from the component and will resume flight testing when ready."

The identified part, which is custom to the 777-9, is a structural component between the engine and the airplane structure, the company said.

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