The 777X boasts new General Electric Co. engines and Boeing's largest-ever wing that comes with a fold to conserve airport space. The plane is slated to enter service by decade's end as the first twin-engine jet to haul a jumbo's payload, while burning 12 percent less fuel than the competing Airbus A350-1000 and 20 percent less than Boeing's 777-300ER, said Bob Feldmann, a Boeing vice president and 777X program manager.
The new plane will also stretch the 777's decades-old aluminum frame and update its pneumatic systems in lieu of the 787's composite fuselage and all-electric architecture. Re-purposing proven technology lowers risk of production delays, a concern for customers after the Dreamliner debuted 3 1/2 years late in 2011, followed by a patchy performance in service.
"This looks like a compelling product and assuming it stays a compelling product, people will buy it and love it," said Richard Aboulafia, an aerospace analyst with Teal Group, a Fairfax, Va.-based consultant. "It will change the accepted logic that major aircraft derivatives are hugely problematic."
The 777 program is central to Boeing's efforts to maintain its lead in the lucrative wide-body market and fend off Airbus, which is positioning its largest A350 as a competing model. Updating wide-body planes requires manufacturers to carefully balance break-through features with proven systems as costs and risks are amplified on long-distance flights.
It's not an easy task. Boeing's redesigned 747-8 jumbo jets, outfitted with Dreamliner wings and new engines, debuted two years later than scheduled in 2011 as engineers sorted out wing flutter and other design issues. The aircraft has struggled to win orders and Boeing has curtailed output twice.
Airlines also balked when Airbus first proposed borrowing the A330's fuselage for the A350 a decade ago, and forced the Toulouse, France-based planemaker to switch to a composite blend that's closer to the Dreamliner frame.
"I actually think Boeing got away with something this time with using the same fuselage and convincing the market that they have a new plane," said Adam Pilarski, a former McDonnell Douglas Corp. executive who is senior vice president at Avitas Inc., a Reston, Va.-based consultant.
Boeing settled on the blend of old and new after years of consultation with airline customers like Emirates, the largest 777 operator, which on Sunday announced 150 777X orders at the Dubai Airshow, and Deutsche Lufthansa, the first carrier to order the 777X.
What sets the jet apart is its 233-foot (71-meter) wingspan and propulsion boasting an 11-foot fan diameter, nearly as wide as the fuselage of a 737 and bigger than any jet engine ever built. The largest of two planned variants seats 407 people, which makes it a competitor to Boeing's 747-8 and Airbus's A380 jumbos while giving it a payload unmatched by any Airbus twin-engine jet.
"It unlocks an incredible amount of fuel efficiency that other airplanes will never even come close to by having that extra 11 feet of span on either side of the airplane," said Feldmann, the 777X program manager.
Lufthansa was concerned that the plane's folding wing could mean higher maintenance costs, especially if it involved complicated technologies, while adding weight that would reduce fuel consumption, Christoph Franz, the carrier's chief executive officer, said in a Nov. 6 interview in New York.
"It was clear right from the beginning that Boeing would have to find an acceptable solution," Franz said. "We feel comfortable" with the result.
GE is developing a new engine that builds on some of the technological advances in the GEnx engine that powers Boeing's 787 Dreamliner and the Leap engine currently under development for the next generation of 737s and Airbus A320s.
That includes fan blades and casings made from lightweight carbon-fiber, fuel combuster and turbine components fashioned from ceramic-matrix composites that can withstand hotter temperatures than metal alloys, and more durable fuel nozzles built in 3-D printers, Bill Millhaem, general manager for the GE9X program, said in a phone interview.
Boeing overhauled how it develops planes after its 787, taking more design work back in house and focusing on simplicity and reducing risk with new 787 variants, the 737 Max and 777X.
"All the development programs are now under one organization," Feldmann said. "We have weekly meetings and I'm hearing first-hand what's going on with the 787-9, -10, Max. One of the lessons is to share what you're finding, whether it's composites or engines."