Story on takeoff updated following completion of flight
The Boeing 777-9 completed its first test flight Saturday, landing at Boeing Field in Seattle at 2:01 pm local time after a three-hour, 52-minute mission over Washington state. Powered by a pair of General Electric GE9X turbofans, the big twin took off northbound at 10:09 am from Boeing’s Paine Field complex in Everett, Washington, marking the start of a flight test program now expected to lead to certification in 2021.
The first flight came after a weather-related postponement on Thursday and an aborted mission on Friday, when gusting tailwinds prevented a northbound takeoff planned as part of the test flight itinerary. Winds on Saturday blew at less than 10 knots, well below the limit at which program managers might have needed to call off the flight for the third time.
The first of four dedicated 777-9 flight test airplanes, WH001 will now undergo checks before resuming testing. The test fleet, which began ground trials in Everett last year, will endure a comprehensive series of tests and conditions on the ground and in the air over the coming months to demonstrate the safety and reliability of the design.
Boeing had originally hoped to gain FAA certification for the larger of a duo of planned 777X variants this year, but engine-related delays and promises of more intense scrutiny from regulators arising from the twin crashes and grounding of the 737 Max have created expectations of a longer wait.
The largest turbofan engine ever developed for an airliner, the GE9X remained a so-called “pacing item” as the industry gathered for the Dubai Airshow in November, by which time the company had delivered three fully compliant engines following retrofit of redesigned stator vane assemblies in the engines’ compressors. By the time of first flight, GE Aviation had delivered six test engines out of eight built to support the Boeing flight test program. In all, the company has built 20 GE9Xs.
Speaking with AIN just ahead of the show, GE9X program head Ted Ingling explained that the process that led to the fix to the problem titanium part involved revamping its geometry to ensure a proper wear profile.
Ingling conceded that the stator vane problem took him and his team by surprise and the fact that the company discovered it fairly late in the development process proved “troubling.”
“This particular one came at us a little late in the program,” said Ingling at the time. “And the nature of it required us to go inside the engine to fix it. And that, by definition, given when we found it and where we found it, drove the schedule. I will say it’s unfortunate from a schedule standpoint but fortunate from a product standpoint. I much preferred to find this in a place where we could fix it and robustly get it behind us than to have something show up in flight tests or certainly in the field.”
In a written statement, a GE spokesman told AIN that the company expected engine certification “later this year.”