Boeing has restarted 777X test flights after a five-month delay, resulting from the discovery of a problem with thrust links during maintenance checks.
The thrust link issue was initially found on Boeing’s 777-9 test aircraft after a routine flight, but the issue was subsequently found on two other test planes.
“During scheduled maintenance, we identified a component that did not perform as designed. Our team is replacing the part and capturing any learnings from the component and will resume flight testing when ready,” Boeing said in a statement on August 19, 2024.
With the issue seemingly resolved, a Boeing 777-9, registered N779XY, took off from Seattle Boeing Field (BFI) on January 16, 2025, and performed a two-and-a-half-hour test flight.
In a comment to Reuters following the flight, Boeing said: “We continue to execute a rigorous test program to demonstrate the safety, performance and reliability of the 777-9.”
The five-month delay to 777X test flights was exacerbated by a seven-week strike by staff that was finally resolved at the end of last year.
There are two variants of the 777X, the larger 777-9 and the smaller 777-8. The aircraft type was originally expected to enter service in 2020, but it is now understood that the earliest this could happen is 2026.
Boeing began certification flight trials of the 777-9 in July 2024, just months before the project hit delays.
Boeing currently has 481 orders for 777X aircraft, with Qatar Airways set to be the launch customer.