BOEING

Fourth Boeing 777X test aircraft, with passenger interior and white paint, returns to flight

Boeing resumed test flights on Wednesday (05/07) with WH004, the fourth prototype of the 777-9X model and the only one in the test fleet equipped with a passenger interior.

The aircraft, registered N779XZ, which had not flown since the end of 2021, will now be used for tests focused on cabin comfort, such as environmental control system tests and noise levels. This aircraft will be delivered to Lufthansa after the tests at Boeing are completed.

According to the manufacturer, the last few months were dedicated to maintenance and configuration updates to prepare the aircraft for the return to operations. During this period, WH004 was stored, while the company prioritized previous phases of testing with the other three prototypes of the 777X campaign.

“Despite the complexity of the modifications, our team remained focused on quality from the beginning of the process,” said Levi King, flight test maintenance leader. Brandon Schmitz, 777X test program manager, highlighted the collective effort: “Our team did an incredible job ensuring that all configuration updates were completed safely, allowing us to move forward toward certification.”

The Boeing 777X, the world’s largest twin-engine jet, is continuing its test program at a rapid pace. Since January, flights have been conducted in several regions of the United States and the Caribbean, including Washington, Montana, New Mexico, Oklahoma, Texas and Curaçao. To date, the campaign has accumulated more than 1,400 flights and approximately 4,000 hours of flight testing.

“With the company’s largest commercial test fleet today, we are committed to completing the program safely and efficiently to deliver this exceptional aircraft to our customers,” said Anita Rudack, deputy chief engineer for the project.

Boeing has received more than 520 orders for the 777X family, which includes the 777-9X, the 777-8XF Freighter and the future 777-8X passenger version. The 777-9X is scheduled for delivery in 2026.

With information from the Boeing Press Office