Boeing has resumed the flight test campaign for the 777X after the test fleet was grounded due to an issue that the manufacturer discovered during scheduled maintenance, writes Simple Flying.
Back in the skies
On January 16, Boeing resumed flight tests of the 777X. The aircraft, registered as N779XY, departed King County International Airport (BFI, also known as Boeing Field) at 14:12 local time (UTC -8). After flying above Washington State and briefly crossing into Oregon, the airframe, also known as WH003, returned to King County/Boeing Field at 16:18 local time.
The flight confirmed previous reports, with AviationWeek first reporting about the development, that Boeing would resume the flight test campaign of the type. The manufacturer suspended flights with the four 777-9 airframes after discovering severed thrust links on N779XY and, subsequently, all four test aircraft.
The flight was the first time any of the 777-9 aircraft had touched the skies since September 2024, when Boeing immediately suspended flights with the type following the discovery of an issue related to the thrust links. On September 8, 2024, N779XY returned from Hawaii, where it had conducted several test flights while being based at Kona International Airport (KOA).
Positive sign
While 2024 began with Boeing landing in hot water following the mid-air door plug blowout on an Alaska Airlines flight in January 2024 and the subsequent fallout, so far in 2025, the company has had no controversies attached to its name.
2025 will be a recovery year for the plane maker as it not only aims to move past the door plug incident, the 52-day machinists strike, and the resulting lackluster delivery numbers but also to deliver on its promises to customers.
This includes certifying three commercial aircraft programmes: the 737 MAX 7, the 737 MAX 10, and the 777X. Boeing has not provided an update on the latter two but previously said that the 777X would enter commercial service in 2026, following another delay that pushed back the type’s entry-into-service (EIS) date from the initial deadline of 2020.
David Calhoun, the now-former president and chief executive officer (CEO) of Boeing, said during his last earnings call on July 31, 2024, that the company identified an engineering solution for the engine anti-ice (EAI) system that has plagued the certification of the 737 MAX 7 and the 737 MAX 10 .
The updated system will be implemented in 2025, enabling Boeing to certify and deliver the 737 MAX 7 and 737 MAX 10, Calhoun added.
Identified during scheduled maintenance
Boeing identified the issue with the severed thrust links in August 2024, with the company’s spokesperson telling Simple Flying at the time that the problem was discovered during scheduled maintenance.
After discovering that the severed thrust links did not perform as designed, Boeing immediately suspended the flight testing campaign. Furthermore, its engineers replaced the part and gathered lessons from the non-conforming part.
The thrust links are a structural component between the engine and the aircraft’s structure, with the part being custom to the 777-9. Each 777-9 has two thrust links, meaning that there is redundancy.
