Boeing 777X Completes First 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."
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