The Boeing 777X, the largest twin-engine passenger plane in the world, recently celebrated a significant milestone when it completed its first test flight.
The 777X is targeted at the long-haul international route market and has a carrying capacity of 426 passengers in a typical two-cabin layout. The total price—$442.2 million—makes it Boeing’s most expensive passenger plane yet. The company intends for the aircraft to take over from its legendary 747. Long-haul carrier Emirates is the 777X’s biggest customer, with 115 jets on order; the plane’s total backlog is currently 309 jets.
The superjumbo aircraft features folding carbon-composite wings that give it an impressive 235-foot wingspan—the largest Boeing has ever produced. In order to fit at existing airport gates, the wing tips are hinged 11 feet from the tip, allowing pilots to fold them upwards when taxiing to the gate. When the plane is ready to take off, the pilots lower the folded wingtips.
The massive plane also features the biggest engine ever built: the ultrapowerful GE9X. Measuring 184 inches at its widest point, the entire passenger cabin of a grounded 737 MAX could fit inside.
Boeing conducted a major overhaul of its production operations to build the 777X. The aircraft maker built a massive new billion-dollar factory on its Everett, Wash., site that featured high-pressure ovens dedicated to fabricating the components of the carbon-composite wings and automated robotic stations, designed by Electroimpact, to assemble them.
There was one significant setback, though: Boeing had developed a robotic method to assemble the metal 777X fuselages called the “Fuselage Automated Upright Build”—an approach that ended up only creating problems for the company. After spending six years and millions of dollars to develop the system, Boeing finally shut down the system in November, choosing to rely instead on human machinists to assemble the components as it had done in the past.
Boeing ran into other problems as well. An extreme stress test of the plane’s structural strength, performed on a completed 777X airframe in September, caused the fuselage to split open just behind the wing and a passenger door, blowing out just as the test approached its target stress level. Fortunately for Boeing, as the aircraft was just 1 percent off from meeting federal aviation standards, it didn’t have to perform a significant redesign on the plane—it just had to reinforce the fuselage in the section where the structure failed.
In the meantime, Boeing’s partner GE also ran into problems with its GE9X engine. During testing, GE found excessive wear on a set of titanium parts inside the engine’s compressor. The resulting fix took nine months to design, test and install in the previously built engines.
Now that its design and build phases are complete, the 777X will undergo an intensive process of testing and certification by the Federal Aviation Administration (FAA)—and that process is expected to be even more rigorous than usual. The FAA’s credibility has been undermined as a result of the 737 MAX debacle, and the regulator is sure to be extra demanding in its review of the aircraft, which could cause the certification process to take longer.
In addition, orders for the 777X have been slow—but Boeing is confident that once certification is complete, interest in the aircraft will rise. With rival Airbus shutting down production of its superjumbo A380, the 777X will be the largest plane on the market. One of the reasons the A380 had lagging sales was that there were a limited number of airports that could fit the superjumbo. The 777X’s folding wings allow the aircraft to fit at the same gates used by a 777 or an A350. And the 777X also beats out the A380 in operating efficiency.
With its new efficient engines and larger wings, the 777X will be able to carry passengers more economically, using less fuel and lowering its carbon footprint. In fact, Boeing says the cost of carrying a passenger on the 777X will be 13 percent lower than on its predecessor, the 777-300ER, and 11 percent lower than the Airbus A350-1000. And the company is betting that, as passengers pay more attention to their carbon footprint when traveling, fuel efficiency will become a deciding factor in determining which plane passengers are willing to fly on, further differentiating the 777X from other less efficient aircraft. Boeing’s argument seems to be that, by fitting more passengers on a single plane that has better fuel efficiency, the 777X is ideal for green air travel.
The number of airline passengers is expected to double over the next two decades, and airport infrastructure is struggling to keep up with the increase. Being able to put more passengers on fewer planes could go a long way toward alleviating that pressure. And the 777X will be able to haul massive amounts of passengers as well as cargo on high-volume routes.
While the 777X is still a long way from entering into commercial service, its first successful test flight has been a bright spot for Boeing. In a congratulatory message to employees after the test flight, Boeing Commercial Airplanes CEO Stan Deal said that after the 777X flight test program is completed, “passengers will put their trust in us every time they fly”—and added that the way the beleaguered plane manufacturer could “earn that continued trust is by working every day to put safety, quality and integrity first in everything we do.”
Read more about the 777X’s challenging path to its first test flight at Engine Problems Are Holding Back Boeing’s 777X.