The fourth Boeing 777X aircraft, known as WH0004 and registered as N779XZ, is set to conduct test flights soon. It was reactivated on April 13, according to data from Flightradar24, after remaining inactive since November 2021. The airframe’s return to action marks the continuation of Boeing’s comprehensive certification program for the 777X series.
The Boeing 777X account on X, previously Twitter — which is not an official Boeing account — identified the reactivation, noting the aircraft’s transponder went online at Seattle Paine Field International Airport before going offline later that day.
Boeing’s other 777-9 test airframes — WH001, WH002, and WH003 — have been flying since January. These resumed operations followed issues with the aircraft’s engine thrust links that had delayed certification progress. The Federal Aviation Administration (FAA) had previously grounded the 737 MAX 9 in early 2024, impacting Boeing’s plans to expand production.
Brian West, Boeing’s Executive Vice President and CFO, stated during a conference that there have been no changes to previously disclosed timelines. He noted that the FAA had recently approved the second phase of flight testing for aerodynamics, brakes, and engines. Boeing aims to certify the 777-X, 737 MAX 7, and 737 MAX 10 in 2025, with the first 777-9 delivery to Lufthansa planned thereafter.
Boeing will reveal its Q1 results on April 23, having announced the delivery of 130 commercial aircraft during that period.
