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 while the 777-9 has seating for 426 passengers and a range of over.
The aircraft are assembled at the Boeing Everett Factory. The 777-9 first flew on January 25, 2020. The program has suffered from numerous delays; Boeing expects the first aircraft to be delivered in 2027., there are 619 total orders for the 777X passenger and freighter versions from 12 customers.
Development
Initial design
In 2011, Boeing refined its response to the revamped Airbus A350 XWB with three improved 777 models, targeting a firm configuration in 2015, first flight 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 in length, for a maximum take-off weight. It would have been powered by 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, with a MTOW and turbofans to compete with the A350-900. An 8LX version with the 9X's MTOW would have had a range of. The current 777-200LR/300ER has a MTOW.The proposals also included a carbon-fiber-reinforced polymer wing with a wingspan of with blended winglets, or up to 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 Airbus A380 but with folding wingtips would stay within the code E like current 777s. The horizontal stabilizers also were 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 bemoaned the loss of engine competition, like Air Lease Corporation's CEO Steven Udvar-Hazy who wanted a choice of engines. Airbus pointed 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 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 was distributed between Charleston, Huntsville, Long Beach, Philadelphia, and St. Louis in the U.S and Moscow, Russia. Its development cost was expected to exceed $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 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.
Production
In December 2014, Boeing began construction on a composites facility in St. Louis to be completed in 2016, to build 777X parts with six autoclaves for the wing and empennage parts, starting in 2017. The 787 'surge' line at the Everett factory would be converted into a 777X early production line by the end of 2015. Boeing built a building adjacent to the Everett factory, with a autoclave, and a robot to wind fiber for the wings. The first 777X was planned to be built on the ex-787 "surge" line.The -9 firm-configuration was reached in August 2015 and assembly of the initial aircraft was to begin in 2017 for a December 2019 introduction advanced from the previously scheduled 2020. With a current 777 production rate of 100 per year, 380 on order at the end of 2013 and no orders at the February 2014 Singapore Airshow, bridging the gap to the 777X deliveries starting from 2020 is a challenge: to stimulate orders, sales of current 777s can be paired with 777Xs and used 777s can be converted to freighters to be sold and stimulate sales.
2017
In April 2017, the initial one-piece wing spar came onto the assembly jig and was about to enter lay-up in June; first parts assembly for the initial -9, a static test airframe, were underway in the purpose-built wing center near Everett, Washington. Four -9s, a fatigue-test airframe, and two -8s were planned for testing. Tests of avionics, power and integrated systems continue in Boeing Field laboratories and were integrated into an "Airplane Zero" in 2017 as 70% detailed design was done by June 2017.The assembly of the first composite wing test example began in Everett in late September 2017 with its top section lowered into a jig for robotic drilling. Boeing launched the 777-9 production on October 23 with the wing spar drilling; its maiden flight was scheduled in the first quarter of 2019, one year before its introduction, perhaps with Emirates.
On November 7, 90% of the engineering drawings were released, with the airframe before the systems: 99% of the wing and 98% of the fuselage drawings were also released. The detailed design phase was expected to be completed in 2017 as avionics, power and other systems are ready for ground tests. Aircraft Numbers 1 and 6 were planned to be used for ground tests; four 777-9s were slated for the flight test and certification campaign, with two 777-8s to come later. Final assembly was planned to start in 2018 before roll-out the same year.
The 777X production techniques were expected to be major cost-cutters. The Fuselage Automated Upright Build system was developed and quietly tested in Anacortes, Washington, 40 miles north of the 777 Everett assembly plant. A major leap in automated production, it drills the tens of thousands of holes in the fuselage more quickly, accurately, and safely. The wings are the first produced by Boeing in composite and not out-sourced like for the 787, and production is largely automated as well. The specifically built billion-dollar factory has excess capacity, laying the foundation for the company's expected future programs: the New Midsize Airplane and later the New Small Airplane to replace the 737.
2018
In February 2018, Subaru completed the first aluminum and titanium center wingbox integrated with main landing gear wheel wells at its Handa factory. The factory was completed in April 2016 and started operation in 2017. It has of floor space and is equipped with automatic riveters, transfer, and painting machines.Boeing's first composite wing spars, stringers, and skin panels are formed in the $1 billion Composite Wing Center before assembly on a new horizontal build line. In February 2018, its wing components were ready to go through assembly as Mitsubishi Heavy Industries, the 787 composite wings manufacturer, advised Boeing on the wing assembly. At this time, 93–95% of the design was released: complete for structures and in progress for systems and engine installation before interiors.
Fuselage subassemblies started shipping on February 7: aft fuselage panels from Mitsubishi Heavy Industries, center and forward fuselage panels from Kawasaki Heavy Industries and the 11/45 center wingbox from Subaru. In March, fuselage assembly was to begin in Everett at a temporary production line between the current 747-8 and 777 assembly lines to avoid disrupting the 777-300ER production. The static airframe and the first flight-test aircraft bodies were to be joined in the second quarter of 2018 and in June–July, respectively.
Scheduled for the start of 2018, the GE9X first flight has been delayed by the variable stator vane actuator arms redesign but the slip should not change the engine certification schedule or the first flight of the 777X. The flight-test engines were to be shipped later in 2018, before the year-end roll out and first flight expected in February 2019. During the component development, two temporary engines were to be placed on the first flight-test aircraft. Wing assembly is difficult, with the light but strong carbon-fiber material being less forgiving than traditional aluminum, and aircraft systems integration in a special demonstration lab is not as quick as planned.
The first 777-9 fuselage assembly started in March 2018. In May 2018, Qatar Airways head Akbar Al Baker thought development was a couple of months late but expects Boeing to catch up, provided no certification issues arise. To avoid disrupting current 777 assembly, a temporary low-rate assembly line was set up for up to 38 airframes before transitioning to the main FAL in the early 2020s. The first -9 roll-out is due in late 2018 and all four -9 prototypes are to join the flight tests by mid-2019, while the two -8 prototypes were to be assembled in 2020 before deliveries.
The first wing was completed in May for static tests before the flight test wings. By July 2018, 98% of its engineering had been released. By September, the static test 777X article was completed, lacking engines and various systems, ahead of its structural testing on ground. The first join on the static-test aircraft was done in 16 days instead of the planned 20 and lessons learned from the 787 wing-body join led to a single defect instead of the hundreds usual in new models.
The final body join of the first flight test aircraft was completed by November, before an early 2019 rollout and a second quarter first flight. By late 2019, it should be joined in the flight program by the other four 777-9 prototypes which were undergoing assembly. The first flight-test aircraft was built 20% faster than the static airframe. At the end of November, the electric systems were powered on and the rollout was expected for February 2019. First deliveries are planned for May 2020 while the first production wing spar was going to be loaded in early December. To position wings and fuselage sections, automated guided vehicles are replacing overhead cranes and "monuments" - large, permanent tooling fixtures. The primary systems were installed by December and its second GE9X engine were to be hung in early 2019.