Boeing has conducted a "productive and successful" first flight of the second 777X aircraft.

Capt. Ted Grady, 777X project pilot, and Capt. Van Chaney, 777/777X chief pilot, flew for just short of three hours over Washington state before landing at Seattle's Boeing Field.

Designated WH002, this aircraft is the second of four which will form a dedicated flight test fleet, and will test handling characteristics and other aspects of aircraft performance. An array of equipment, sensors and monitoring devices throughout the cabin allows the onboard team to document and evaluate the aircraft's response to test conditions in real time.

The 777X test plan lays out a comprehensive series of tests and conditions on the ground and in the air to demonstrate the safety and reliability of the design. To date, crews have flown the first aircraft nearly 100 hours at a variety of flap settings, speeds, altitudes and system settings as part of the initial evaluation of the flight envelope. With initial airworthiness now demonstrated, the team can safely add personnel to monitor testing onboard instead of relying solely on a ground-based telemetry station, unlocking testing at greater distances.

The Boeing 777X family includes the 777-8 and the 777-9, the newest members of Boeing's market-leading widebody family.