Boeing 777X – the largest twin-engine jet in the world
In January, the new Boeing 777X-9 powered by GE9X engines took to the skies for the first time.
03.2020 | Text: Thorsten Rienth
Thorsten Rienth writes as a freelance journalist for AEROREPORT. In addition to the aerospace industry, his technical writing focuses on rail traffic and the transportation industry.
- The folding wingtips reduce the wingspan on the ground from 71.75 to 64.82 meters—taking it below the critical 65 meter mark and enabling the 777X to fit into “normal” airport gates.
Adding length to the CFRP wings also makes sense from an aerodynamic perspective: Boeing says this improves the lift-to-drag ratio and increases the fuel efficiency in cruise.
The interior of the 777X is inspired by that of the Boeing 787 Dreamliner. But the 777X has added selling points that include an even quieter cabin and higher levels of humidity—the latter improving the air quality in the cabin for passengers.
The Boeing 777X-9 is the world’s longest twinjet, featuring a fuselage that measures 76.72 meters.
Boeing gives the aircraft range as 7,285 nautical miles for 426 passengers in a two-class configuration. This is equivalent to nearly 13,500 kilometers. At 69.79 meters, the slightly shorter 777X-8 can fly for an even longer range of 8,730 nautical miles (16,170 kilometers) with 384 passengers on board.
The 777X is powered by two GE9X engines, each equipped with an 11-stage high-pressure compressor that delivers a pressure ratio of 27:1. The engine’s overall pressure ratio is 60:1.
In the summer of 2019, the GE9X set a Guinness World Record as the most powerful commercial aircraft jet engine: under test conditions, the engine reached 134,300 pounds of thrust—appreciably higher than the previous record holder, the GE90-115B, which delivers 127,900 pounds of thrust.
According to GE, the GE9X consumes ten percent less fuel than the GE90-115B, the engine that powers the Boeing 777-300er.
Engine for the Boeing 777X-9: GE9X
MTU is a four-percent shareholder in the GE9X program, – assuming development and production responsibility for the turbine center frame (TCF).
For MTU, the engine provides a firm foothold in today’s cutting-edge generation of widebody aircraft. The TCF is one of the most sophisticated components in the commercial engine business: exposed to extreme stresses, it serves a duct for the hot gas flowing from the high-pressure turbine past structural components and cables to the low-pressure turbine at temperatures of up to 1,000 degrees Celsius—with minimum aerodynamic losses. MTU has many years of experience with this module, which it also develops and produces for the GP7000 (Airbus A380) and the GEnx (Boeing 787 Dreamliner, 747-8) engine programs.