November 25, 2013
Credit: Boeing Concept
If anyone in the industry questioned Boeing's wisdom in basing its next long-range twin on the 777 rather than a bolder, all-new design, any doubts were dispelled at the air show here last week, where the much-anticipated 777X was launched on a $95 billion-plus wave of 259 orders and commitments.
The new twinjets combine an updated version of the otherwise conventional current 777 fuselage with all new General Electric GE9X engines and an all-composite wing. The 777X is not only the heir apparent to the 777-300ER, Boeing's dominant long-haul twin, but it is also the company's challenger to the Airbus A350. And it is Boeing's first attempt to tap the intercontinental market in the 400-plus seat range below the 747-8. Yet, while the 777-8X and -9X bear an outward resemblance to today's big twin, new details unveiled here reveal a different story beneath the skin.
At 250 ft. long, the 777-9X will be exactly the same length as today's 747-8, and 8 ft. longer than the 777-300ER. Configured to carry more than 400 passengers, the aircraft will have a range of more than 8,200 nm, according to Boeing industry officials say the target is likely to be around 8,400 nm. The 777-8X, with capacity for 350 passengers, is sized close to the current 777-300ER and will have a 9,400-nm range. The aircraft will be powered by the GE9X, which will be rated at around 105,000 lb. thrust, confirms David Joyce GE president and CEO.
“It is a step-change in aircraft design and a step-change in propulsion, but we have to wait seven or eight years for this to come,” says Tim Clark, president of Emirates Airlines, which led the launch group at Dubai with orders and commitments for 150 777Xs in addition to options for 50 more. “The -9X will have a 16 to 17 percent delta in fuel burn [compared to the current 777-300ER] and is an aircraft that is redesigned inside and has a new wing. It is all-composite and has great lift over drag. The -8X is about the same size as the 777-300ER but will be able to fly 17 to 18 hours nonstop and with the same fuel efficiency as the -9X,” he adds.
“We are confident in the performance of the aircraft, and we know we are significantly better than the A350-1000,” says 777X Vice President and General Manager Bob Feldmann. Boeing predicts the 777-9X will have 12% better fuel burn than the A350-1000 while the -8X will be 5-6% better. The performance estimates combine the planned benefit of the GE9X, which is targeted at a 10% lower fuel burn than the GE90-115B used on the 777-300ER, as well as the improved efficiency of the 233-ft.-span wing. The higher-aspect-ratio, carbon-fiber-reinforced polymer wing is designed to give a 12% improvement in lift-drag ratio and will be characterized by a 787-like dihedral. “We are confident in the wing design. It produces incredible increases in lift and decreases in drag,” despite weighing more than the current metallic wing, adds Feldmann. “It's the fourth time we've done a large composite wing, and clearly we are going down the 787 derivative path.”
Within the broader context of Boeing's twin-aisle market strategy, the launch of the 777X also marks “the final chapter” of the repositioning of the widebody product line, says Scott Fancher, Boeing Airplane Development vice president and general manager. Following in the footsteps of the 787-8, -9 and -10 launches, the 777-8X and -9X bridge the gap with the 747-8, partially overlapping with the larger aircraft and providing a twin-engine replacement for 747-400s. “We sized up the -8X to take advantage of the -9X technology to give us an aircraft like the 777-300ER but with greater range and payload. The -8X, for instance, will be able to carry 17 tonnes more cargo than the A350-1000,” says Fancher. “With the -9X, we think that's where the heart of the widebody market is.”
Although Middle Eastern carriers such as Emirates, Etihad Airways and Qatar Airways were highlighted at Dubai as launch customers, Boeing says this does not mean the 777X is over-optimized for other users. Lufthansa was the first to actually commit to the 777X with an $11 billion deal to acquire 34 777-9Xs in mid-September. Vice President Nico Buchholz says, “by jumping first for the -9X, we also solicited in the contract what we wanted it to do.” The performance “box” created for Lufthansa's requirement also suits the other airlines, which worked with Boeing as a group to define the new family.