Boeing's 4th 777X Test Plane Expected To Fly Soon

The fourth Boeing 777X should be flying soon, with the company activating the airframe, known as WH0004, which is registered as N779XZ, on April 13. Other 777-9 airframes, namely WH001, WH002, and WH003, have been actively flying since January after Boeing resumed the certification campaign. Reactivating WH0004 the company reactivated WH004, registered as N779XZ, on April 13.

This was flagged by the Boeing 777X account on X -formerly known as Twitter- which is not an official Boeing account that follows the production and other matters related to the plane maker’s newest twin-aisle aircraft. According to Flightradar24 records, the airframe’s transponder went online at Seattle Paine Field International Airport (PAE), previously known as Paine Field, with the callsign ‘BOE777’ at around 09:49 local time (UTC -7). The transponder went offline at around 11:32, per the flight tracking website.



While other 777-9 test frames have been actively flying throughout the past four years, N779XZ/WH004 has been sitting at Seattle Pain Field since November 2021, when it last operated a flight from King County International Airport (BFI), also known as Boeing Field. The aircraft flew to the other airport within the Seattle area, housing Boeing’s Everett production site, where the plane maker assembles widebody aircraft. Following the ending of the production of the 747-8 in January 2023 , Boeing unveiled plans to open a fourth 737 MAX production line at its Everett facilities, which will lose another commercial aircraft program , the 767F, in a few years (the KC-46, based on the 767, will continue to be built there).

In January 2024, several days after the Federal Aviation Administration (FAA) temporarily grounded the 737 MAX 9, the agency outlined that it would not approve the expansion of production or additional production lines until the quality of Boeing’s aircraft improves, a sentiment echoed by the current administration’s officials at the Department of Transportation (DOT) and the FAA. 777X Test Flights Nevertheless, Boeing resumed test flying the 777-9 in January after a problem with the aircraft’s thrust links essentially grounded the type’s certification efforts, which had progressed to the Type Inspection Authorization (TIA) stage , and continued to progress with the certification program. Flightradar24 records showed that N779XW, also known as WH001, operated its first flight on January 23, flying from Paine Field to Moses Lake Grant County International Airport (MWH), while N779XX, also known as WH002, took to the skies for the first time since August 2024 on February 5, flying from King County/Boeing Field to Moses Lake.

N779XY, also known as WH003, which had been grounded since September 2024 and was the first aircraft to have cracked engine thrust links, which is a structural component between the engine and the aircraft structure, resumed flights on January 16. At the time, it departed and landed back at Boeing Field. Its last flight at the time of writing was on April 11, as was N779XW and N779XX’s, which also had test flights on the same day.

Boeing last operated a 777-9 flight in September 2024, when it ferried N779XY from Hawaii to the continental United States. Certification Soon While Boeing will disclose its Q1 results on April 23, with the plane maker already having disclosed that it delivered 130 commercial aircraft during the quarter, during the Bank of America Global Industrials Conference on March 19, Brian West, the Executive Vice President and Chief Financial Officer (CFO) of Boeing, disclosed that there were no changes to previously disclosed timelines. During the conference, West updated that in the two weeks leading up to the event, the FAA approved the second phase of the flight testing of the 777-9, which is when the certification focuses on “aerodynamics, the brakes, the engine.

” At the time, the 777-9 had 3,700 flight test hours, West said. On January 28, on the company’s Q4 2024 earnings call, Kelly Ortberg, the President and Chief Executive Officer (CEO) of Boeing, affirmed that the timeline of the 777X, 737 MAX 7, and 737 MAX 10, has not changed, with the plane maker aiming to certify the trio in 2025 and deliver the first 777-9 to Lufthansa..