Boeing 777X will build on 787 Dreamliner technology as the largest and most efficient twin engine jet

The Boeing777X is twin-engine, twin-aisle will build on the success of the 777 and 787 Dreamliner. The 777X is the largest and most efficient twin-engine jet in the world. Its folding raked wingtip and optimized span deliver greater efficiency, significant fuel savings and complete airport gate compatibility. And its GE9X engine is the most advanced, fuel-efficient commercial engine ever.

Performance, however, is just part of the story. The cabin interior of the 777X is inspired by the comforts and conveniences of the 787 Dreamliner and will include larger windows, a wider cabin, new lighting and enhanced architecture — all of which will be custom tailored for a unique 777X experience.

The 777X will feature new engines, new composite material wings, and technologies from the Boeing 787.

777-8X: US$360.5 million [350 passengers, 10700 mile range]
777-9X: US$388.7 million [406 passengers, 9400 mile range]

In December 2014, Boeing began construction on a new 367,000-square-foot (34,100 m2) composites facility in St. Louis to build 777X parts; completion is set for 2016. The expansion will create about 700 new jobs. The facility will feature six autoclaves with work on 777X wing and empennage parts to start in 2017. There are already about 300 firm orders

In May 2015 Boeing announced it would convert the current 787 ‘surge’ line at Everett by the end of 2015 into an early production line for the 777X with the first 777X expected to roll off that line in 2018

Design plans call for the 777X to feature cabin design details that were originally introduced on the Boeing 787 Dreamliner. These include larger windows than prior commercial aircraft, increased cabin pressure equivalent to 6,000 feet (1,800 m) altitude, higher ceilings, and more humidity. Structural changes are required versus the original 777 fuselage design in order to incorporate these design improvements as well as greater cabin width. Folding wingtips to fit the current 777 size category are planned for the 777X