The Boeing 777X is the latest series of the long-range, wide-body, twin-engine jetliners in the Boeing 777 family from Boeing Commercial Airplanes. The 777X features new GE9X engines, new composite wings with folding wingtips, greater cabin width and seating capacity, and technologies from the Boeing 787. The 777X was launched in November 2013 with two variants: the 777-8 and the 777-9. The 777-8 provides seating for 384 passengers and has a range of while the 777-9 has seating for 426 passengers and a range of over .
The 777X program was proposed in the early 2010s with assembly at the Boeing Everett Factory and the wings built at a new building adjacent to the Everett factory. , there are 363 total orders for the 777X passenger and freighter versions from ten identified customers and other buyers. The 777-9 first flew on January 25, 2020, with deliveries delayed multiple times and expected to commence in 2025.
Development
Initial design
In 2011, Boeing refined its response to the revamped Airbus A350 XWB with three 777X models, targeting a firm configuration in 2015, flying in late 2017 or 2018, and entering service by 2019. The 407–passenger 777-9X should stretch the 777-300ER by four frames to in length, for a maximum take-off weight (MTOW) and powered by engines, targeting per-seat 21% better fuel burn and 16% better operating cost. The smaller 353-seat 777-8X was to stretch the 777-200ER by ten frames to , with a MTOW and turbofans to compete with the A350-900 with improvements over the -200ER like the 777-9X over the 777-300ER. A 8LX with the 9X MTOW would have a range. The current 777-200LR/300ER have a MTOW.
A new carbon-fiber-reinforced polymer (CFRP) wing with a wingspan of with blended winglets, or up to with raked wingtip provide for a 10% larger wing area. It would fall into ICAO aerodrome code F like the 747-8 and A380 but with folding wingtips it would stay within the code E like current 777s. Horizontal stabilizers would be extended.
Engine selection
The General Electric GE90-115B of the earlier 777-200LR and -300ER variants has a 42:1 overall pressure ratio and 23:1 compressor ratio. Rolls-Royce Plc proposed its RB3025 concept with a fan diameter, a 12:1 bypass ratio, and a 62:1 overall pressure ratio, targeting a fuel burn of more than 10% lower than the GE90-115B and 15% lower than its Trent 800 powering the 777; the RB3025 concept has a composite fan, a core derived from the Trent 1000, and advanced HP materials. Pratt & Whitney responded with the thrust PW1000G geared turbofan architecture. GE Aviation proposed the GE9X with a diameter fan, a 10:1 bypass ratio, a 60:1 overall pressure ratio, and 27:1 HP compressor ratio for a 10% fuel burn reduction.
In March 2013, Boeing selected the GE9X with a fan. It is the largest fan made by GE. In the rest of 2013, thrust was bumped to to support the MTOW growing from and increasing the payload-range, with a possible envisioned.
Some customers bemoan the loss of engine competition, like Air Lease Corporation's CEO Steven Udvar-Hazy who wanted a choice of engines. Airbus points out that handling more than one engine type adds millions of dollars to an airliner cost. Pratt and Whitney said: "Engines are no longer commodities...the optimization of the engine and the aircraft becomes more relevant."
Launch
In 2012, with the Boeing 737 MAX in development and the 787-10 launch in preparation, Boeing decided to slow 777X development to reduce the risk with introduction still forecast for 2019. On May 1, 2013, Boeing's board of directors approved selling the 353-seat 777-8LX to replace the 777-300ER from 2021, after the larger 406-seat -9X.
The design work is distributed between Charleston, Huntsville, Long Beach, Philadelphia, and St. Louis in the U.S and Moscow, Russia. Its development cost could be over $5 billion with at least $2 billion for the carbon-composite wing.
On September 18, 2013, Lufthansa became its launch customer by selecting 34 Boeing 777-9X airliners, along with 25 Airbus A350-900s to replace its 22 747-400s and 48 A340-300/600s for its long-haul fleet. At the November 2013 Dubai Airshow, the -8X for 350 passengers over a range and the -9X, seating more than 400 over were launched with 259 orders and commitments for US$95 billion (~$ in ) at list prices. This was the largest commercial aircraft launch by dollar value with Emirates ordering 150, Qatar Airways 50, and Etihad Airways 25, in addition to the September 2013 Lufthansa commitment for 34 aircraft. Boeing dropped the variants' "X" suffix, while keeping the 777X program name at the 2015 Dubai Airshow.