After discovering a broken part that grounded its entire test fleet, Boeing is repairing the 777-9 that is stuck in Hawaii to fly it Home.

As of this writing, none of Boeing’s four 777-9 test aircraft have flown since the third one (WH003) landed back in Hawaii on the 15th of August. That’s when technicians inspecting the aircraft discovered a severed part in the thrust link assembly of one of the aircraft’s engines.

As we have seen, a thrust link is a component that transfers thrust loads from the front of the engine to the pylon and wing. Each engine has two of them, and each one should be capable of keeping the engine together in case the other fails.

After the first discovery of problems with the 777-9 in Hawaii, Boeing found cracks in two other aircraft in Washington State. The fourth 777-9, WH004, had not flown for many months and didn’t appear to be part of the FAA certification testing.

Flying the 777-9 From Hawaii – When?

Boeing designed these thrust links. Aviation Week reports that since the Hawaii event, Boeing has found cracks in at least one thrust link belonging to the fourth 777-9. This means that ALL 777-9s now have cracked or severed thrust links.

Engineers are reportedly removing the thrust links from the fourth aircraft as part of Boeing’s investigation into the matter. This aircraft has flown the least of all 777-9s.

The discovery of cracks in aircraft with very little flight time, suggests that the cause of the problem might not have to do with the number of flight hours or any testing-related stresses. In any case, Boeing is working to replace the thrust links on the 777-9 that is still in Hawaii, to bring it to the mainland.

Completing this work away from Boeing’s own facilities brings its own challenges, especially when dealing with such a large aircraft (and engines). This should return home early in September, possibly next week.

#Latest photo from Hawaii, Boeing test crew inspecting and replacing the thrust link on WH003 (N779XY).

It's expected to return to Seattle on August 30 for further investigation.#777X #GE9X #Boeing777X pic.twitter.com/aRXaF0DlTO

— Boeing 777X (@b777xlovers) August 27, 2024

Since that discovery, Boeing has been keeping its 777-9 customers and the FAA informed about its findings. However, airlines reportedly still don’t know which specific part of the thrust link assembly failed.

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