Boeing 777X

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 changes for the 777X include General Electric GE9X engines, composite wings with folding wingtips, greater cabin width and seating capacity, and technologies from the Boeing 787. The 777X program was launched in November 2013 to develop two variants: the 777-8 and the 777-9. The 777-8 provides seating for 395 passengers and has a range of 8,745 nautical miles [nmi] (16,196 km; 10,064 mi) while the 777-9 has seating for 426 passengers and a range of over 7,285 nmi (13,492 km; 8,383 mi).

The aircraft are assembled at the Boeing Everett Factory. As of September 2025^[update], there are 565 total orders for the 777X passenger and freighter versions from 12 customers. The 777-9 first flew on January 25, 2020. The program has suffered from numerous delays; as of October 2025,^[update] Boeing expects the first aircraft to be delivered in 2027.

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 then-proposed, 407–passenger 777-9X stretched the 777-300ER by four frames to 250 ft 11 in (76.48 m) in length, for a 759,000 lb (344 t) maximum take-off weight (MTOW). It would have been powered by 99,500 lbf (443 kN) engines, targeting per-seat 21% better fuel burn and 16% better operating cost. Early designs of the smaller 353-seat 777-8X proposed stretching the 777-200ER by ten frames to a length of 228 ft 2 in (69.55 m), with a 694,000 lb (315 t) MTOW and 88,000 lbf (390 kN) turbofans to compete with the A350-900. An 8LX version with the 9X's MTOW would have had a range of 9,480 nmi (17,560 km; 10,910 mi). The current 777-200LR/300ER has a 775,000 lb (352 t) MTOW.

The proposals also included a carbon-fiber-reinforced polymer (CFRP) wing with a wingspan of 213 or 225 ft; 2,560 or 2,700 in (65 or 68.6 m) with blended winglets, or up to 233 ft 5 in (71.1 m) with raked wingtip would have provided for a 10% larger wing area. The aircraft would have fallen into ICAO aerodrome code F like the 747-8 and A380 but with 22 ft 6 in (6.9 m) folding wingtips would stay within the 213 ft 4 in (65.02 m) code E like current 777s. Horizontal stabilizers also were extended.

The General Electric GE90-115B of the earlier 777-200LR and -300ER variants has a 42:1 overall pressure ratio and 23:1 HP compressor ratio. Rolls-Royce Plc proposed its RB3025 concept with a 132 in (335 cm) 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 100,000 lbf (440 kN) thrust PW1000G geared turbofan architecture. GE Aviation proposed the GE9X with a 128 in (325 cm) 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 132 in (335 cm) fan. It is the largest fan made by GE. In the rest of 2013, thrust was bumped to 102,000 and 105,000 lbf (450 and 470 kN) to support the MTOW growing from 769,413 to 775,000 lb (349,000 to 351,534 kg) and increasing the payload-range, with a possible 108,000 lbf (480 kN) envisioned.

Some customers bemoaned 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."

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.