Boeing 777X#Testing

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 {{cvt|250|ft|11|in|m}} in length, for a {{cvt|759,000|lb|t}} maximum take-off weight (MTOW). It would have been powered by {{cvt|99,500|lbf|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 {{cvt|69.55|m|ftin|order=flip}}, with a {{cvt|315|t|lb|order=flip}} MTOW and {{cvt|88,000|lbf|kN}} turbofans to compete with the A350-900. An 8LX version with the 9X's MTOW would have had a range of {{cvt|9,480|nmi}}. The current 777-200LR/300ER has a {{cvt|775000|lb|t}} MTOW.

The proposals also included a carbon-fiber-reinforced polymer (CFRP) wing with a wingspan of {{cvt|65|or|68.6|m|ft in|order=flip}} with blended winglets, or up to {{cvt|233|ft|5|in|1}} 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 {{cvt|22|ft|6|in|1}} folding wingtips would stay within the {{cvt|213|ft|4|in}} code E like current 777s. Horizontal stabilizers also were extended.{{cite web |archive-url= https://web.archive.org/web/20120318195444/http://www.flightglobal.com/Features/Boeing-777-special/777X/ |title= A special look at the future prospects of the Boeing 777 |work= Flight International |archive-date= March 18, 2012 |url= http://www.flightglobal.com:80/Features/Boeing-777-special/777X/ |access-date= November 9, 2018 |url-status= live |df= mdy-all}}

The General Electric GE90-115B of the earlier 777-200LR and -300ER variants has a 42:1 overall pressure ratio and 23:1 {{abbr|HP|high pressure}} compressor ratio. Rolls-Royce Plc proposed its RB3025 concept with a {{cvt|132|in|cm|sigfig=3}} 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 {{cvt|100,000|lbf|kN}} thrust PW1000G geared turbofan architecture. GE Aviation proposed the GE9X with a {{cvt|325|cm|in|order=flip}} 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 {{cvt|132|in|cm|0}} fan. It is the largest fan made by GE.{{cite press release |url= https://www.geaviation.com/press-release/ge90-engine-family/ge-fans-out-testing-new-ge9x-fan-blades |title= GE Fans Out on Testing of New GE9X Fan Blades |publisher= GE Aviation |date= August 21, 2013 |access-date= October 23, 2017 |archive-date= October 24, 2017 |archive-url= https://web.archive.org/web/20171024043056/https://www.geaviation.com/press-release/ge90-engine-family/ge-fans-out-testing-new-ge9x-fan-blades |url-status= live}} In the rest of 2013, thrust was bumped to {{cvt|102,000|and|105,000|lbf|kN}} to support the MTOW growing from {{cvt|349,000|to|351,534|kg|lb|order=flip}} and increasing the payload-range, with a possible {{cvt|108,000|lbf|kN}} envisioned.{{cite news |url= http://www.aspireaviation.com/2013/10/24/boeing-widebody-dominance-777x-success/ |title= Boeing's widebody dominance hinges on 777X success |work= Aspire Aviation |date= October 24, 2013 |access-date= November 17, 2013 |archive-date= April 29, 2016 |archive-url= https://web.archive.org/web/20160429011213/http://www.aspireaviation.com/2013/10/24/boeing-widebody-dominance-777x-success/ |url-status= live}}

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."{{cite news |author=Wall |first1=Robert |last2=Ostrower |first2=Jon |last3=Jones |first3=Rory |date=July 15, 2014 |title=Aircraft Makers Narrow Engine Options |url=https://www.wsj.com/articles/aircraft-makers-narrow-engine-options-1405457174 |url-access=subscription |url-status=live |archive-url=https://web.archive.org/web/20171023231135/https://www.wsj.com/articles/aircraft-makers-narrow-engine-options-1405457174 |archive-date=October 23, 2017 |access-date=October 23, 2017 |work=Wall Street Journal}}

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.{{cite news |author=Gates |first=Dominic |date=August 22, 2012 |title=Boeing slows the pace on 777X |url=http://seattletimes.com/html/businesstechnology/2018972134_boeing777x23.html |url-status=live |archive-url=https://web.archive.org/web/20150216215752/http://seattletimes.com/html/businesstechnology/2018972134_boeing777x23.html |archive-date=February 16, 2015 |access-date=November 20, 2013 |work=Seattle Times}} 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.{{cite web |title= Boeing Board Gives Approval To Offer 777X |url= http://aviationweek.com/commercial-aviation/boeing-board-gives-approval-offer-777x |author= Guy Norris |work= Aviation Week & Space Technology |date= May 1, 2013 |access-date= October 23, 2017 |archive-date= October 24, 2017 |archive-url= https://web.archive.org/web/20171024054441/http://aviationweek.com/commercial-aviation/boeing-board-gives-approval-offer-777x |url-status= live}}

The design work is distributed between Charleston, Huntsville, Long Beach, Philadelphia, and St. Louis in the U.S and Moscow, Russia.{{cite news |title= Boeing spreads 777X design work to Charleston, Moscow, defence sites |url= http://www.flightglobal.com/news/articles/boeing-spreads-777x-design-work-to-charleston-moscow-defence-sites-392371/ |date= October 30, 2013 |work= Flight Global |access-date= November 20, 2013 |archive-date= January 2, 2016 |archive-url= https://web.archive.org/web/20160102165415/https://www.flightglobal.com/news/articles/boeing-spreads-777x-design-work-to-charleston-moscow-defence-sites-392371/ |url-status= live}} Its development cost could be over $5 billion with at least $2 billion for the carbon-composite wing.{{cite news |url= https://www.reuters.com/article/us-boeing-assembly/boeing-seen-in-advanced-talks-to-make-777x-near-seattle-idUSBRE9A30BV20131104 |title= Boeing seen in advanced talks to make 777X near Seattle |author= Tim Hepher |date= November 4, 2013 |work= Reuters |access-date= July 19, 2018 |archive-date= July 19, 2018 |archive-url= https://web.archive.org/web/20180719233254/https://www.reuters.com/article/us-boeing-assembly/boeing-seen-in-advanced-talks-to-make-777x-near-seattle-idUSBRE9A30BV20131104 |url-status= live}}

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.{{cite news |title= Split Lufthansa widebody order includes firm 777X |url= http://www.flightglobal.com/news/articles/split-lufthansa-widebody-order-includes-firm-777x-390732/ |author= Michael Gubisch |work= Flight Global |date= September 19, 2013 |access-date= November 20, 2013 |archive-date= January 2, 2016 |archive-url= https://web.archive.org/web/20160102165415/https://www.flightglobal.com/news/articles/split-lufthansa-widebody-order-includes-firm-777x-390732/ |url-status= live}} At the November 2013 Dubai Airshow, the -8X for 350 passengers over a {{cvt|9,300|nmi}} range and the -9X, seating more than 400 over {{cvt|8,200|nmi}} were launched with 259 orders and commitments for US$95 billion (~${{Format price|{{Inflation|index=US-GDP|value=95000000000|start_year=2013}}}} in {{Inflation/year|US-GDP}}) 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.{{cite press release |title= Boeing Launches 777X with Record-Breaking Orders and Commitments |url= http://boeing.mediaroom.com/2013-11-17-Boeing-Launches-777X-with-Record-Breaking-Orders-and-Commitments |publisher= Boeing |date= November 17, 2013 |access-date= November 17, 2013 |archive-date= February 13, 2014 |archive-url= https://web.archive.org/web/20140213081058/http://boeing.mediaroom.com/2013-11-17-Boeing-Launches-777X-with-Record-Breaking-Orders-and-Commitments |url-status= live}} Boeing dropped the variants' "X" suffix, while keeping the 777X program name at the 2015 Dubai Airshow.{{cite news |author=Kaminski-Morrow |first=David |date=November 8, 2015 |title=DUBAI: Boeing drops 'X' from stretched 777 designation |url=https://www.flightglobal.com/news/articles/dubai-boeing-drops-x-from-stretched-777-designati-418791/ |url-status=live |archive-url=https://web.archive.org/web/20151117015203/https://www.flightglobal.com/news/articles/dubai-boeing-drops-x-from-stretched-777-designati-418791/ |archive-date=November 17, 2015 |access-date=November 16, 2015 |work=Flight Global}} In June 2017, Lufthansa was considering delaying 777X deliveries and could limit its -9 orders to 20 and order more A350s.{{cite news |author=Weiss |first1=Richard |last2=Johnsson |first2=Julie |date=June 2, 2017 |title=Lufthansa Weighs Slowing Deliveries of 777X in Boeing Blow |url=https://www.bloomberg.com/news/articles/2017-06-01/lufthansa-mulls-dragging-out-boeing-777x-orders-to-conserve-cash |url-status=live |archive-url=https://web.archive.org/web/20180213195613/https://www.bloomberg.com/news/articles/2017-06-01/lufthansa-mulls-dragging-out-boeing-777x-orders-to-conserve-cash |archive-date=February 13, 2018 |access-date=February 13, 2018 |work=Bloomberg News}}

File:Emirates Boeing 777 fleet at Dubai International Airport Wedelstaedt.jpg of its largest operator, Emirates |alt=View of airport tarmac with terminal building and multiple airliners parked adjacent to it.]]

In December 2014, Boeing began construction on a {{cvt|367000|sqft|m2|adj=on}} 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.{{cite news |url= http://americanmachinist.com/news/boeing-building-new-plant-composite-materials |title= Boeing Building New Plant for Composite Materials |work= American Machinist |date= December 17, 2014 |access-date= October 23, 2017 |archive-date= October 23, 2017 |archive-url= https://web.archive.org/web/20171023231200/http://www.americanmachinist.com/news/boeing-building-new-plant-composite-materials |url-status= live}} The 787 'surge' line at the Everett factory would be converted into a 777X early production line by the end of 2015.{{cite news |author=Gates |first=Dominic |date=May 8, 2015 |title=Boeing will close 787 surge line to make way for producing 777X |url=http://www.seattletimes.com/business/boeing-aerospace/boeing-will-close-787-surge-line-to-make-way-for-producing-777x/ |url-status=live |archive-url=https://web.archive.org/web/20150522080020/http://www.seattletimes.com/business/boeing-aerospace/boeing-will-close-787-surge-line-to-make-way-for-producing-777x/ |archive-date=May 22, 2015 |access-date=May 9, 2015 |work=Seattle Times}} Boeing built a {{cvt|1300000|sqft|m2}} building adjacent to the Everett factory, with a {{cvt|120|ft}} autoclave,{{cite web |last1=Boyle |first1=Alan |title=Boeing opens its giant, billion-dollar 777X composite wing factory in Everett |url= https://www.geekwire.com/2016/boeing-opens-billion-dollar-777x-composite-wing-factory-everett/ |publisher=GeekWire |access-date=December 28, 2017 |date=May 20, 2016 |archive-date=December 28, 2017 |archive-url= https://web.archive.org/web/20171228232343/https://www.geekwire.com/2016/boeing-opens-billion-dollar-777x-composite-wing-factory-everett/ |url-status=live}} and a robot to wind fiber for the wings.{{cite news |title=Massive, speedy robots ready to build composite wings for Boeing 777X |url= https://www.seattletimes.com/business/boeing-aerospace/massive-speedy-robots-ready-to-build-composite-wings-for-boeing-777x/ |website=The Seattle Times |date=February 5, 2016 |access-date=December 28, 2017 |archive-date=December 28, 2017 |archive-url= https://web.archive.org/web/20171228232839/https://www.seattletimes.com/business/boeing-aerospace/massive-speedy-robots-ready-to-build-composite-wings-for-boeing-777x/ |url-status=live}} The first 777X was planned to be built on the ex-787 "surge" line.{{cite news |author=Flynn |first=David |date=May 9, 2015 |title=First Boeing 777X tipped for 2018 |url=http://www.ausbt.com.au/first-boeing-777x-tipped-for-2018 |url-status=live |archive-url=https://web.archive.org/web/20161119063131/http://www.ausbt.com.au/first-boeing-777x-tipped-for-2018 |archive-date=November 19, 2016 |access-date=May 9, 2015 |website=Australian Business Traveller}}

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.{{cite news |author=Perry |first=Dominic |date=March 11, 2016 |title=Boeing advances 777X service entry: sources |url=https://www.flightglobal.com/news/articles/boeing-advances-777x-service-entry-sources-423032/ |url-status=live |archive-url=https://web.archive.org/web/20161005091025/https://www.flightglobal.com/news/articles/boeing-advances-777x-service-entry-sources-423032/ |archive-date=October 5, 2016 |access-date=September 11, 2016 |work=Flight Global}} 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.{{cite news |author=Ostrower |first=Jon |date=February 13, 2014 |title=Boeing plans new tactics to sell 777 |url=https://www.wsj.com/news/articles/SB10001424052702304703804579380830515165164 |url-access=subscription |url-status=dead |archive-url=https://web.archive.org/web/20170207050736/https://www.wsj.com/news/articles/SB10001424052702304703804579380830515165164 |archive-date=February 7, 2017 |access-date=March 13, 2017 |work=Wall Street Journal |df=mdy-all}}

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.{{cite news |url= http://aviationweek.com/paris-air-show-2017/civil-aviation-programs-watch#slide-14-field_images-1639711 |title= Civil Aviation Programs To Watch |date= June 9, 2017 |work= Aviation Week & Space Technology |access-date= June 13, 2017 |archive-date= May 27, 2021 |archive-url= https://web.archive.org/web/20210527121753/https://aviationweek.com/pike-space-force-should-be-established#slide-14-field_images-1639711 |url-status= live}}

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.{{cite news |url= https://www.flightglobal.com/news/articles/777xs-first-test-wing-enters-final-assembly-441762/ |title= 777X's first test wing enters final assembly |date= October 3, 2017 |author= Craig Hoyle |work= Flightglobal |access-date= October 3, 2017 |archive-date= October 3, 2017 |archive-url= https://web.archive.org/web/20171003171537/https://www.flightglobal.com/news/articles/777xs-first-test-wing-enters-final-assembly-441762/ |url-status= live}} 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.{{cite news |author=Trimble |first=Stephen |date=October 23, 2017 |title=Boeing ceremonially kicks off 777-9 assembly |url=https://www.flightglobal.com/news/articles/boeing-ceremonially-kicks-off-777-9-assembly-442427/ |url-status=live |archive-url=https://web.archive.org/web/20171024130642/https://www.flightglobal.com/news/articles/boeing-ceremonially-kicks-off-777-9-assembly-442427/ |archive-date=October 24, 2017 |access-date=October 24, 2017 |work=Flightglobal}}

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 are released.{{cite news |author=Trimble |first=Stephen |date=November 12, 2017 |title=Boeing achieves 90% drawing milestone on 777-9 |url=https://www.flightglobal.com/news/articles/dubai-boeing-achieves-90-drawing-milestone-on-777-443168/ |url-status=live |archive-url=https://web.archive.org/web/20171113165649/https://www.flightglobal.com/news/articles/dubai-boeing-achieves-90-drawing-milestone-on-777-443168/ |archive-date=November 13, 2017 |access-date=November 13, 2017 |work=Flightglobal}} 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 (No. 2 to 5) 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.{{cite news |author=Goold |first=Ian |date=November 8, 2017 |title=Boeing Forges Ahead with Flight-test Campaigns |url=https://www.ainonline.com/aviation-news/air-transport/2017-11-08/boeing-forges-ahead-flight-test-campaigns |url-status=live |archive-url=https://web.archive.org/web/20171113165522/https://www.ainonline.com/aviation-news/air-transport/2017-11-08/boeing-forges-ahead-flight-test-campaigns |archive-date=November 13, 2017 |access-date=November 13, 2017 |work=AIN}}

The 777X production techniques were expected to be major cost-cutters. The Fuselage Automated Upright Build (FAUB) 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 (NMA) and later the New Small Airplane to replace the 737.{{cite news |author=Hamilton |first=Scott |date=January 8, 2018 |title=Pontifications: 2018 is a year of Transformations |url=https://leehamnews.com/2018/01/08/pontifications-2018-year-transformations/ |url-status=live |archive-url=https://web.archive.org/web/20180728221718/https://leehamnews.com/2018/01/08/pontifications-2018-year-transformations/ |archive-date=July 28, 2018 |access-date=January 8, 2018 |work=Leeham}}

File:Passenger Experience Week 2018, Hamburg (1X7A3836) (cropped).jpg

In February 2018, Subaru (ex–Fuji Heavy Industries) 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 {{convert|11600|m2|ft2|order=flip}} of floor space and is equipped with automatic riveters, transfer, and painting machines.{{cite web |url= https://www.subaru.co.jp/press/news-en/2018_02_09_5450/ |title= Subaru Corporation Completes First Boeing 777X Center Wing Section |date= February 9, 2018 |work= Subaru Corporation |access-date= January 24, 2020 |archive-date= September 13, 2020 |archive-url= https://web.archive.org/web/20200913040651/https://www.subaru.co.jp/press/news-en/2018_02_09_5450/ |url-status= live}}{{cite news |author=Waldron |first=Greg |date=February 12, 2018 |title=Subaru completes first 777X centre wing box |url=https://www.flightglobal.com/news/articles/subaru-completes-first-777x-centre-wing-box-445809/ |url-status=live |archive-url=https://web.archive.org/web/20180212083229/https://www.flightglobal.com/news/articles/subaru-completes-first-777x-centre-wing-box-445809/ |archive-date=February 12, 2018 |access-date=February 12, 2018 |work=Flightglobal}}

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.{{cite news |author=Norris |first=Guy |date=February 26, 2018 |title=Boeing Poised To Begin 777X Assembly |url=http://aviationweek.com/new-civil-aircraft/boeing-poised-begin-777x-assembly |url-status=live |archive-url=https://web.archive.org/web/20180226213150/http://aviationweek.com/new-civil-aircraft/boeing-poised-begin-777x-assembly |archive-date=February 26, 2018 |access-date=February 26, 2018 |work=Aviation Week & Space Technology}} 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.{{cite news |author=Hepher |first=Tim |date=March 16, 2018 |title=Boeing moves to keep 777X on track after engine snag |url=https://uk.reuters.com/article/us-boeing-777x-interview/boeing-moves-to-keep-777x-on-track-after-engine-snag-idUKKCN1GS2T0 |url-status=dead |archive-url=https://web.archive.org/web/20180317033849/https://uk.reuters.com/article/us-boeing-777x-interview/boeing-moves-to-keep-777x-on-track-after-engine-snag-idUKKCN1GS2T0 |archive-date=March 17, 2018 |access-date=March 17, 2018 |work=Reuters}}

The first 777-9 fuselage assembly started in March 2018.{{cite news |author=Trimble |first=Stephen |date=March 23, 2018 |title=Boeing starts fuselage assembly for first 777-9 |url=https://www.flightglobal.com/news/articles/boeing-starts-fuselage-assembly-for-first-777-9-447028/ |url-status=live |archive-url=https://web.archive.org/web/20180323201341/https://www.flightglobal.com/news/articles/boeing-starts-fuselage-assembly-for-first-777-9-447028/ |archive-date=March 23, 2018 |access-date=March 23, 2018 |work=Flightglobal}} 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.{{cite news |author=Young |first=Sarah |date=May 2, 2018 |title=Qatar Airways CEO says 777X behind schedule but sees Boeing catching up |url=https://www.reuters.com/article/us-qatar-airways-britain-boeing/qatar-airways-ceo-says-delays-on-777x-program-but-sees-boeing-catching-up-idUSKBN1I31LB |url-status=live |archive-url=https://web.archive.org/web/20180504155212/https://www.reuters.com/article/us-qatar-airways-britain-boeing/qatar-airways-ceo-says-delays-on-777x-program-but-sees-boeing-catching-up-idUSKBN1I31LB |archive-date=May 4, 2018 |access-date=May 4, 2018 |work=Reuters}} 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.{{cite news |author=Norris |first=Guy |date=May 17, 2018 |title=777X Wing Assembly Ramps Up On Automated Horizontal Build Line |url=http://aviationweek.com/new-civil-aircraft/777x-wing-assembly-ramps-automated-horizontal-build-line |url-status=live |archive-url=https://web.archive.org/web/20180526044822/http://aviationweek.com/new-civil-aircraft/777x-wing-assembly-ramps-automated-horizontal-build-line |archive-date=May 26, 2018 |access-date=May 25, 2018 |work=Aviation Week & Space Technology}}

The first wing was completed in May for static tests before the flight test wings.{{cite twitter |user= BoeingAirplanes |number= 1000111875936391169 |title= [...] the first #777X wing structure is complete [and] will be used in static testing. The first wings for flight test airplanes will soon follow. |date= May 25, 2018}} By July 2018, 98% of its engineering had been released.{{cite news |author=Polek |first=Gregory |date=July 12, 2018 |title=Boeing Seeing Steady Progress with 777X |url=https://www.ainonline.com/aviation-news/air-transport/2018-07-12/boeing-seeing-steady-progress-777x |url-status=live |archive-url=https://web.archive.org/web/20180715123116/https://www.ainonline.com/aviation-news/air-transport/2018-07-12/boeing-seeing-steady-progress-777x |archive-date=July 15, 2018 |access-date=July 15, 2018 |work=AIN online}} By September, the static test 777X article was completed, lacking engines and various systems, ahead of its structural testing on ground.{{cite news |author=Hemmerdinger |first=Jon |date=September 5, 2018 |title=Boeing reveals first assembled 777X ahead of static tests |url=https://www.flightglobal.com/news/articles/pictures-boeing-reveals-first-assembled-777x-ahead-451693/ |url-status=live |archive-url=https://web.archive.org/web/20180906115319/https://www.flightglobal.com/news/articles/pictures-boeing-reveals-first-assembled-777x-ahead-451693/ |archive-date=September 6, 2018 |access-date=September 6, 2018 |work=Flightglobal}} 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.{{cite news |author=Norris |first=Guy |date=November 20, 2018 |title=Boeing Completes Final Body Join For First 777-9 |url=https://aviationweek.com/aerospace/program-management/boeing-completes-final-body-join-first-777-9 |work=Aviation Week Network}} The first flight-test aircraft was built 20% faster than the static airframe.{{cite news |author=Norris |first=Guy |date=December 5, 2018 |title=In Pictures: First Boeing 777-9 In Final Assembly |url=http://aviationweek.com/commercial-aviation/pictures-first-boeing-777-9-final-assembly |url-status=live |archive-url=https://web.archive.org/web/20181208054519/http://aviationweek.com/commercial-aviation/pictures-first-boeing-777-9-final-assembly |archive-date=December 8, 2018 |access-date=December 5, 2018 |work=Aviation Week & Space Technology}} 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.{{cite news |author=Norris |first=Guy |date=December 3, 2018 |title='Power On' Marks Key Milestone For First 777-9 On Path To First Flight |url=http://aviationweek.com/commercial-aviation/power-marks-key-milestone-first-777-9-path-first-flight |url-status=live |archive-url=https://web.archive.org/web/20210527124114/https://aviationweek.com/air-transport/power-marks-key-milestone-first-777-9-path-first-flight |archive-date=May 27, 2021 |access-date=December 3, 2018 |work=Aviation Week & Space Technology}} The primary systems were installed by December and its second GE9X engine were to be hung in early 2019.{{cite news |author=Gates |first=Dominic |date=December 27, 2018 |title=The big jet behind Everett's big doors: Boeing readies first 777X to fly |url=https://www.seattletimes.com/business/boeing-aerospace/the-big-jet-behind-everetts-big-doors-boeing-readies-first-777x-to-fly-next-year/ |url-status=live |archive-url=https://web.archive.org/web/20181227170748/https://www.seattletimes.com/business/boeing-aerospace/the-big-jet-behind-everetts-big-doors-boeing-readies-first-777x-to-fly-next-year/ |archive-date=December 27, 2018 |access-date=December 27, 2018 |newspaper=The Seattle Times}}

Engines were installed by early January 2019.{{cite news |author=Gates |first=Dominic |date=January 4, 2019 |title=The biggest jet engines ever seen are set to roar on Boeing's 777X |url=https://www.seattletimes.com/business/boeing-aerospace/the-biggest-jet-engines-ever-seen-are-set-to-roar-on-boeings-777x/ |url-status=live |archive-url=https://web.archive.org/web/20190104174520/https://www.seattletimes.com/business/boeing-aerospace/the-biggest-jet-engines-ever-seen-are-set-to-roar-on-boeings-777x/ |archive-date=January 4, 2019 |access-date=January 4, 2019 |newspaper=The Seattle Times}} The first 777-9 body join happened in February for a delivery planned in summer 2020 to Lufthansa.{{cite news |author=Jones |first=Max Kingsley |date=February 19, 2019 |title=First 777-9 for Lufthansa comes together in Everett |url=https://www.flightglobal.com/news/articles/picture-first-777-9-for-lufthansa-comes-together-i-455919/ |url-status=live |archive-url=https://web.archive.org/web/20190220064052/https://www.flightglobal.com/news/articles/picture-first-777-9-for-lufthansa-comes-together-i-455919/ |archive-date=February 20, 2019 |access-date=February 20, 2019 |work=Flightglobal}} The roll-out of the prototype occurred on March 13, 2019, in a low-key employees-only event overshadowed by the crash of an Ethiopian Airlines 737 MAX 8 on March 10.{{cite news |last1=Norris |first1=Guy |title=Boeing Unveils 777-9 In Low-Key Event |url= https://aviationweek.com/commercial-aviation/boeing-unveils-777-9-low-key-event |work=aviationweek.com |date=March 14, 2019 |language=en |access-date=March 14, 2019 |archive-date=November 17, 2019 |archive-url= https://web.archive.org/web/20191117062825/https://aviationweek.com/commercial-aviation/boeing-unveils-777-9-low-key-event |url-status=live}}

The GE9X engines installed on the 777X prototype were first run on May 29. However, a compressor anomaly occurred with another engine during pre-delivery tests, and the maiden flight previously planned for no earlier than June 26 was delayed while the engines are modified to a final certifiable configuration.{{cite news |title=GE9X Engine Anomaly Likely To Delay Boeing 777X First Flight |url= https://aviationweek.com/commercial-aviation/ge9x-engine-anomaly-likely-delay-boeing-777x-first-flight |work=Aviation Week Network |date=June 6, 2019 |language=en |access-date=June 6, 2019 |archive-date=May 27, 2021 |archive-url= https://web.archive.org/web/20210527124114/https://aviationweek.com/ge9x-engine-anomaly-likely-delay-boeing-777x-first-flight |url-status=live}} {{As of |2019 |06 |17}}, GE expressed confidence that the engine would receive certification during the fall and that the first flight of the 777X would still occur in 2019.{{cite news |last1=Gubisch |first1=Michael |title=GE redesigns GE9X compressor part for 777X engine |url= https://www.flightglobal.com/news/articles/paris-ge-redesigns-ge9x-compressor-part-for-777x-en-458998/ |work=Flightglobal.com |date=17 June 2019 |access-date=June 17, 2019 |archive-date=June 17, 2019 |archive-url= https://web.archive.org/web/20190617093628/https://www.flightglobal.com/news/articles/paris-ge-redesigns-ge9x-compressor-part-for-777x-en-458998/ |url-status=live}} The 777X test plan was later revised as several months are required to develop and test fixes to the GE9X, and first flight slipped to October–November.{{cite news |author=Norris |first=Guy |date=Jun 17, 2019 |title=Boeing 777X First Flight Delayed 'Several' Months |url=https://aviationweek.com/commercial-aviation/boeing-777x-first-flight-delayed-several-months |url-status=live |archive-url=https://web.archive.org/web/20210527124115/https://aviationweek.com/air-transport/boeing-777x-first-flight-delayed-several-months |archive-date=May 27, 2021 |access-date=June 17, 2019 |work=Aviation Week Network}} By June, the first prototype began low-speed taxi tests.{{cite tweet |number= 1142130182939119621 |title= Our first #777X flight test airplane made its runway debut! [...] |date= 21 Jun 2019 |user= BoeingAirplanes}}

On July 24, Boeing announced that the GE9X engine issue would delay the maiden flight until 2020. The company continued to target first deliveries in 2020,{{cite news |last1=Hemmerdinger |first1=Jon |url= https://www.flightglobal.com/news/articles/ge9x-engine-issue-pushes-777x-first-flight-to-2020-459877 |title=GE9X engine issue pushes 777X first flight to 2020 |work=Flightglobal |date=July 24, 2019 |access-date=July 25, 2019 |archive-date=May 31, 2020 |archive-url= https://web.archive.org/web/20200531170459/https://www.flightglobal.com/airframers/ge9x-engine-issue-pushes-777x-first-flight-to-2020/133665.article |url-status=live}} though it intends to boost production of current-generation 777 freighters in 2020.{{cite news |last1=Norris |first1=Guy |title=Boeing Plans 777F Production Boost To Offset 777X Delays |url= https://aviationweek.com/awincommercial/boeing-plans-777f-production-boost-offset-777x-delays |work=aviationweek.com |date=July 24, 2019 |language=en |access-date=July 25, 2019 |archive-date=May 27, 2021 |archive-url= https://web.archive.org/web/20210527124115/https://aviationweek.com/air-transport/boeing-plans-777f-production-boost-offset-777x-delays |url-status=live}} GE Aviation in Ohio is recalling four GE9X turbofans from Boeing in Washington state in Antonov An-124 freighters from Volga-Dnepr Airlines, mounted in 26 x 14 x 13 ft (8 x 4 x 4 m), 36,000 lb (16.3 t) stands.{{cite news |author=Hemmerdinger |first=Jon |date=Aug 20, 2019 |title=GE recalls 777X turbofans to address compressor issue amid scramble to minimise 777X delays |url=https://www.flightglobal.com/news/articles/ge-recalls-777x-turbofans-to-address-compressor-issu-460379/ |url-status=live |archive-url=https://web.archive.org/web/20190821072740/https://www.flightglobal.com/news/articles/ge-recalls-777x-turbofans-to-address-compressor-issu-460379/ |archive-date=August 21, 2019 |access-date=August 21, 2019 |work=Flightglobal}}

On September 5, in the presence of FAA inspectors, a door blew off on the 777X static test airframe during the ultimate load test, which is conducted with the airplane stressed and pressurized beyond normal operating limits.{{cite news |last1=Gates |first1=Dominic |title=Door blows out during ground test on Boeing 777X jet |url= https://www.seattletimes.com/business/boeing-aerospace/door-blows-out-during-ground-test-on-boeing-777x-jet/ |work=The Seattle Times |date=September 6, 2019 |access-date=September 7, 2019 |archive-date=September 9, 2019 |archive-url= https://web.archive.org/web/20190909061101/https://www.seattletimes.com/business/boeing-aerospace/door-blows-out-during-ground-test-on-boeing-777x-jet/ |url-status=live}}{{cite news |last1=Harger |first1=Charlie |title=Door blows off Boeing 777X during stress test |url= https://komonews.com/news/local/door-blows-off-boeing-777x-during-stress-test |work=Komo News |date=September 6, 2019 |access-date=September 7, 2019 |archive-date=September 7, 2019 |archive-url= https://web.archive.org/web/20190907084553/https://komonews.com/news/local/door-blows-off-boeing-777x-during-stress-test |url-status=live}} Depending on the outcome of its root cause investigation, Boeing should have time to modify the failed part and repeat the test during the margin from the existing engine-related delays.{{cite news |last1=Norris |first1=Guy |title=Boeing suspends 777X loads tests after pressure failure |url= https://aviationweek.com/commercial-aviation/boeing-suspends-777x-loads-tests-after-pressure-failure |work=aviationweek.com |date=September 7, 2019 |language=en |access-date=September 8, 2019 |archive-date=May 27, 2021 |archive-url= https://web.archive.org/web/20210527124115/https://aviationweek.com/air-transport/boeing-suspends-777x-loads-tests-after-pressure-failure |url-status=live}} At 99% of ultimate load, 1.48 times the limit load, the aluminum skin ruptured under the center fuselage, aft of the wing, and the damaged structure extended up the fuselage side to a passenger plug door which blew out − and not an outward-hinged cargo door.{{cite news |author=Gates |first=Dominic |date=Nov 27, 2019 |title=Boeing 777X's fuselage split dramatically during September stress test |url=https://www.seattletimes.com/business/boeing-aerospace/boeing-777xs-fuselage-split-dramatically-during-september-stress-test/ |url-status=live |archive-url=https://web.archive.org/web/20191128080217/https://www.seattletimes.com/business/boeing-aerospace/boeing-777xs-fuselage-split-dramatically-during-september-stress-test/ |archive-date=November 28, 2019 |access-date=November 28, 2019 |newspaper=Seattle Times}}

In October 2019, the JATR board created to review the Boeing 737 MAX certification noted that the FAA would need to assess more thoroughly how modifications interact with the aircraft. The FAA did not announce how its review and certification of the 777X may be affected. The 777X was already a year behind schedule as service introduction was targeted for 2022, a further delay due to the certification as a derivative could risk key orders.{{cite news |title=Certification process for 777X is another hurdle for Boeing |url= https://leehamnews.com/2020/01/16/certification-process-for-777x-is-another-hurdle-for-boeing/ |work=Leeham News and Analysis |date=16 January 2020 |access-date=January 24, 2020 |archive-date=January 27, 2020 |archive-url= https://web.archive.org/web/20200127172100/https://leehamnews.com/2020/01/16/certification-process-for-777x-is-another-hurdle-for-boeing/ |url-status=live}}

Boeing received the first flight compliant GE9X on October 18 with a second engine due by the end of the month, for a mid-November power up.{{cite news |author=Norris |first=Guy |date=Oct 22, 2019 |title=GE Aviation Delivers Compliant GE9X Engine To Boeing For 777X |url=https://aviationweek.com/commercial-aviation/ge-aviation-delivers-compliant-ge9x-engine-boeing-777x |url-status=live |archive-url=https://web.archive.org/web/20210527124115/https://aviationweek.com/air-transport/ge-aviation-delivers-compliant-ge9x-engine-boeing-777x |archive-date=May 27, 2021 |access-date=October 23, 2019 |work=Aviation Week Network}} On November 13, the FAUB robotic system was abandoned after six years of implementation, to use human machinists more.{{cite news |url= https://www.seattletimes.com/business/boeing-aerospace/boeing-abandons-its-failed-fuselage-robots-on-the-777x-handing-the-job-back-to-machinists/ |title= Boeing abandons its failed fuselage robots on the 777X, handing the job back to machinists |date= Nov 13, 2019 |author= Dominic Gates |newspaper= Seattle Times |archive-url= https://web.archive.org/web/20200818071435/https://www.seattletimes.com/business/boeing-aerospace/boeing-abandons-its-failed-fuselage-robots-on-the-777x-handing-the-job-back-to-machinists/ |archive-date= August 18, 2020}} By mid-November, a pair of flight compliant engines were installed on the first 777-9.{{cite news |url= https://aviationweek.com/commercial-aviation/boeing-targets-777x-test-restart-ge-reveals-ge9x-upgrade-details |title= Boeing Targets 777X Test Restart As GE Reveals GE9X Upgrade Details |date= Nov 15, 2019 |author= Guy Norris |work= Aviation Week Network |access-date= November 17, 2019 |archive-date= May 27, 2021 |archive-url= https://web.archive.org/web/20210527124116/https://aviationweek.com/air-transport/boeing-targets-777x-test-restart-ge-reveals-ge9x-upgrade-details |url-status= live}}

As part of an investigation by the FAA into the fatal crashes of the Boeing 737 MAX aircraft, emails were released that showed that a problematic supplier of parts for the 737 MAX flight simulators was still being used for 777X simulators, on an even more aggressive schedule.{{cite news |author=Tovey |first=Alan |date=January 18, 2020 |title=Staff emails claim Boeing 777X 'shares Max problem' |work=The Telegraph |url= https://www.telegraph.co.uk/business/2020/01/18/staff-emails-claim-boeing-777x-shares-max-problem/ |url-status=live |access-date= |archive-date=January 20, 2020 |archive-url= https://web.archive.org/web/20200120012722/https://www.telegraph.co.uk/business/2020/01/18/staff-emails-claim-boeing-777x-shares-max-problem/}} Boeing stated that the 777X does not have an equivalent of the Maneuvering Characteristics Augmentation System (MCAS) that is installed on the 737 MAX and that played a role in two crashes.{{Cite web |last=Hemmerdinger|first=Jon|date=2020-02-06|title=Boeing reveals details of 777X flight-test plan |url= https://www.flightglobal.com/air-transport/boeing-reveals-details-of-777x-flight-test-plan/136588.article |url-status=live |access-date=2021-02-09|website=Flight Global |archive-date=February 15, 2021 |archive-url= https://web.archive.org/web/20210215014203/https://www.flightglobal.com/air-transport/boeing-reveals-details-of-777x-flight-test-plan/136588.article}}

The first test flight took place on January 25, 2020, at 10:09 a.m. from Paine Field in Everett, and ended in Boeing Field in Seattle after 3 hours and 52 minutes.{{cite news |last=Gates |first=Dominic |author-link=Dominic Gates |date=January 25, 2020 |title=Boeing's massive 777X takes off on first flight |url= https://www.seattletimes.com/business/boeing-aerospace/lifted-on-massive-wings-boeing-777x-scheduled-to-finally-take-flight-friday-morning/ |work=The Seattle Times |access-date=January 25, 2020 |archive-date=January 25, 2020 |archive-url= https://web.archive.org/web/20200125040856/https://www.seattletimes.com/business/boeing-aerospace/lifted-on-massive-wings-boeing-777x-scheduled-to-finally-take-flight-friday-morning/ |url-status=live}} The second 777X first flew on April 30, by which point the first had explored the flight envelope for nearly 100 hours. After the first delivery was pushed back from 2021 to 2022, the third aircraft made its maiden flight on August 3; it is slated for avionics systems, APU, flight loads and propulsion performance tests.{{cite news|author=Wolfsteller|first=Pilar|date=4 August 2020|title=Boeing's third 777X aircraft begins flight testing|work=|url= https://www.flightglobal.com/airframers/boeings-third-777x-aircraft-begins-flight-testing/139624.article|url-status=live|access-date=|archive-date=January 25, 2021|archive-url= https://web.archive.org/web/20210125223121/https://www.flightglobal.com/airframers/boeings-third-777x-aircraft-begins-flight-testing/139624.article}}

In January 2021, Boeing expected to add two more 777-9s to the test program, aiming for certification in 2021.{{cite press release |url= https://boeing.mediaroom.com/2020-04-30-Second-Boeing-777X-Completes-First-Flight |title= Second Boeing 777X Completes First Flight |publisher= Boeing |date= April 30, 2020 |access-date= May 1, 2020 |archive-date= January 25, 2021 |archive-url= https://web.archive.org/web/20210125012052/https://boeing.mediaroom.com/2020-04-30-Second-Boeing-777X-Completes-First-Flight |url-status= live}} In early 2021, first delivery was pushed to late 2023.{{Cite press release|title=Boeing CEO Updates Employees on Fourth-Quarter Results|url= https://boeing.mediaroom.com/news-releases-statements?item=130819|date=2021-01-27|publisher=Boeing|access-date=January 27, 2021|archive-date=January 27, 2021|archive-url= https://web.archive.org/web/20210127133706/https://boeing.mediaroom.com/news-releases-statements?item=130819|url-status=live}} The delay was due to updated type certification requirements and the impact of the COVID-19 pandemic on aviation, costing a $6.5 billion charge.{{cite news|author=Hemmerdinger|first=Jon|date=27 January 2021|title=Boeing delays first 777-9 delivery to 2023, takes $6.5bn charge|work=Flightglobal|url= https://www.flightglobal.com/airframers/boeing-delays-first-777-9-delivery-to-2023-takes-65bn-charge/142146.article|url-status=live|access-date=|archive-date=January 27, 2021|archive-url= https://web.archive.org/web/20210127151926/https://www.flightglobal.com/airframers/boeing-delays-first-777-9-delivery-to-2023-takes-65bn-charge/142146.article}}

On June 27, 2021, The Seattle Times reported on an FAA letter to Boeing dated May 13 delaying type certification until mid to late 2023, pushing deliveries to 2024. The FAA cited a serious test flight incident involving an "uncommanded pitch event" and a lack of "design maturity".{{Cite news |last=Gates |first=Dominic |date=2021-06-27 |title=Citing a serious flight test incident and lack of design maturity, FAA slows Boeing 777X certification |work=The Seattle Times |url= https://www.seattletimes.com/business/boeing-aerospace/citing-a-serious-flight-test-incident-and-lack-of-design-maturity-faa-slows-boeing-777x-certification/ |access-date= January 26, 2022}}

{{anchor|2022}}

In April 2022, after an "updated assessment of the time required to meet certification requirements", Boeing again delayed 777X deliveries, this time to 2025.{{Cite news |last=Gates |first=Dominic |date=2021-06-27 |title=Boeing 777x delayed to 2025 |work=AirwaysMag |url= https://airwaysmag.com/boeing-777x-delayed-2025/ |access-date= April 23, 2022}} In November 2022, it was revealed that the GE9X engine on one of the four test 777-9s had suffered a technical issue on October 6. Boeing subsequently paused the test program while GE investigated the issue.{{Cite web |last=Meier |first=Ricardo |date=2022-11-30 |title=Boeing acknowledges 777X engine problem after grounding flights two months ago |url=https://www.airdatanews.com/boeing-acknowledges-777x-engine-problem-after-grounding-flights-two-months-ago/ |access-date=2022-12-01 |website=Air Data News |language=en-US}}{{Cite web |title=Emirates' Clark: No A380 or B747 will lead to rising fares |url=https://www.aerotime.aero/articles/32785-emirates-tim-clark-future-a380-operation-interview |access-date=2022-12-01 |website=www.aerotime.aero |date=November 29, 2022 |language=en}}

In May 2024, launch customer Lufthansa was expecting its first deliveries in 2026.{{cite news |url= https://aviationweek.com/air-transport/airlines-lessors/lufthansa-sees-first-777-9-delivery-slipping-2026 |title= Lufthansa Sees First 777-9 Delivery Slipping Into 2026 |author= Jens Flottau, Guy Norris |date= May 2, 2024 |work= Aviation Week |access-date=2024-05-24}}{{cite web | url=https://aviationweek.com/air-transport/aircraft-propulsion/boeing-reconfirms-2026-target-777x-first-delivery | title=Boeing Reconfirms 2026 as Target for 777X First Delivery | Aviation Week Network }} As of September 2024, its estimate has been revised to an entry into service by early 2027.[https://www.airliners.de/lufthansa-erwartet-erneute-boeing-777x-verspaetung/76894 "Lufthansa richtet sich auf erneute Boeing-777X-Verspätung ein" (Lufthansa prepares for another Boeing 777X delay)]. airliners.de (German), 26 September 2024.

In August 2024, routine inspection following a test flight in Hawaii led to Boeing grounding its 777X test fleet. A structural link between the engine and wing was found to be damaged, while cracks were found in the same component on other aircraft in the fleet.{{Cite web |title=Boeing discovers engine part defect and grounds its 777X test airplanes |url=https://www.seattletimes.com/business/boeing-aerospace/boeing-discovers-engine-part-defect-and-grounds-its-777x-test-airplanes/ |access-date=2024-08-19 |website= seattletimes.com |date=August 19, 2024 |language=en}}

On October 11, 2024, Boeing confirmed that the expected first delivery of the aircraft had slipped to 2026, following development challenges and workplace strikes at the company.{{cite news |last1=Sharwood |first1=Simon |title=Boeing again delays the 777X – the plane that's supposed to turn things around |url=https://www.theregister.com/2024/10/14/boeing_layoffs_delays/ |work=The Register |date=October 14, 2024}} Emirates cast doubt on this forecast, noting that Boeing had no clear timeline for resuming certification flights.{{cite news |last1=Hemmerdinger |first1=Jon |title=Emirates' CEO questions Boeing's new 777-9 timeline |url=https://www.flightglobal.com/airframers/emirates-ceo-questions-boeings-new-777-9-timeline/160310.article |work=Flight Global |date=October 15, 2024 |language=en}}

Flight testing resumed on January 16, 2025 following grounding in August 2024 due to cracks discovered in engine mounting hardware.{{Cite web |last=Norris |first=Guy |date=January 17, 2025 |title=Boeing Confirms 777X Certification Flight Restart |url=https://aviationweek.com/air-transport/aircraft-propulsion/boeing-confirms-777x-certification-flight-restart |access-date=2025-01-19 |website=aviationweek.com}}{{Cite web |last=Catchpole |first=Dan |date=January 16, 2025 |editor-last=Freed |editor-first=Jamie |title=Boeing resumes 777X test flights after grounding in August |url=https://www.reuters.com/business/aerospace-defense/boeing-resumes-777x-test-flights-after-grounding-august-2025-01-17/ |access-date=January 19, 2025 |website=Reuters}} Boeing confirmed expected first delivery, to Lufthansa, had been pushed back to 2026 from the previous 2025 estimate.

File:14 11 2021 Dubai Air Show (51680086518).jpg

File:777X Roll-Out (40407369583).jpg

The 777X has a longer composite wing with folding wingtips. Due to this, the 777X is the first commercial transport aircraft to have "wingtip controls" in the cockpit.{{Cite web |title=777X Flight Deck And Wing Fold Controls Unveiled |url=https://aviationweek.com/air-transport/aircraft-propulsion/777x-flight-deck-wing-fold-controls-unveiled |access-date=2021-08-21|website= Aviation Week Network (aviationweek.com)}} Based on the 787 wing but with less sweep, this wing has a higher lift-to-drag ratio, aspect ratio increased from 9:1 to 10:1, area increased from {{cvt|4702|to|5562|sqft}}, and usable fuel capacity increased from {{cvt|320863|to|350410|lb}}.

To stay within the size category of the current 777 with a less than {{cvt|65|m|ft|order=flip}} wingspan, it features {{convert|3.5|m|ft|order=flip}} folding wingtips with the folding wingtip actuation system made by Liebherr Aerospace.{{cite news |url= http://www.flightglobal.com/news/articles/liebherr-division-to-build-777x-folding-wing-tip-systems-411789/ |title= Liebherr division to build 777X folding wing-tip systems |date= April 30, 2015 |work= Flight Global |access-date= May 3, 2015 |archive-date= March 13, 2016 |archive-url= https://web.archive.org/web/20160313131210/https://www.flightglobal.com/news/articles/liebherr-division-to-build-777x-folding-wing-tip-systems-411789/ |url-status= live}} The mechanism was demonstrated for Aviation Week at the Boeing Everett Factory in October 2016; the folding movement should be complete in 20 seconds and be locked in place at the end.{{cite news |url= http://aviationweek.com/technology/watch-boeing-777x-folding-wingtip |title= Watch: Boeing 777X Folding Wingtip |date= October 31, 2016 |work= Aviation Week |access-date= October 31, 2016 |archive-date= December 25, 2016 |archive-url= https://web.archive.org/web/20161225185136/http://aviationweek.com/technology/watch-boeing-777x-folding-wingtip |url-status= live}} Specific alerts and procedures are needed to handle a malfunction.{{cite news |author=Trimble |first=Stephen |date=March 15, 2018 |title=Boeing publishes plan for "non-normal" 777X wingtip ops |url=https://www.flightglobal.com/news/articles/boeing-publishes-plan-for-non-normal-777x-wingtip-446789/ |url-status=live |archive-url=https://web.archive.org/web/20180315065347/https://www.flightglobal.com/news/articles/boeing-publishes-plan-for-non-normal-777x-wingtip-446789/ |archive-date=March 15, 2018 |access-date=March 15, 2018 |work=Flightglobal}}

As existing regulations do not cover the folding wingtips, the FAA issued special conditions, including proving their load-carrying limits, demonstrating their handling qualities in a crosswind when raised, alerting the crew when they are not correctly positioned while the mechanism and controls will be further inspected.{{cite news |author=Norris |first=Guy |date=November 15, 2017 |title=FAA Proposes Special Conditions For 777X Folding Wingtips |url=http://aviationweek.com/commercial-aviation/faa-proposes-special-conditions-777x-folding-wingtips |url-status=live |archive-url=https://web.archive.org/web/20171117142801/http://aviationweek.com/commercial-aviation/faa-proposes-special-conditions-777x-folding-wingtips |archive-date=November 17, 2017 |access-date=November 17, 2017 |work=Aviation Week Network}} Those ten special conditions were published on May 18, 2018, covering worst-case scenarios.{{cite web |url=https://www.federalregister.gov/documents/2018/05/18/2018-10576/special-conditions-the-boeing-company-model-777-8-and-777-9-airplanes-folding-wingtips |title=Special Conditions: The Boeing Company Model 777-8 and 777-9 Airplanes; Folding Wingtips |date=May 18, 2018 |publisher=Federal Register}}

Transported by sea from Subaru in Nagoya to Everett, the center wing-box is similar in size to the legacy 777 but is more reinforced and heavier, with more titanium.{{cite news |author=Waldron |first=Greg |date=December 5, 2018 |title=Subaru gears up for 777X with eye on efficiency, cost |url=https://www.flightglobal.com/news/articles/subaru-gears-up-for-777x-with-eye-on-efficiency-co-454156/ |url-status=live |archive-url=https://web.archive.org/web/20181206143900/https://www.flightglobal.com/news/articles/subaru-gears-up-for-777x-with-eye-on-efficiency-co-454156/ |archive-date=December 6, 2018 |access-date=December 5, 2018 |work=Flightglobal}}

The internal cabin width is increased from the previous 777 models' {{cvt|{{#expr:19*12+3}}|to|{{#expr:19*12+7}}|in|cm|0}} through thinner interior cabin walls and better insulation to allow {{cvt|18.0|in|cm}} wide seats in 10-abreast economy.{{cite news |author=Garcia |first=Marisa |date=July 23, 2014 |title=Boeing's New 777X Designs Intensify the Race for Space on Airlines |url=http://skift.com/2014/07/23/boeings-new-777x-designs-intensify-the-race-for-space-on-airlines/#1 |url-status=live |archive-url=https://web.archive.org/web/20161230090255/https://skift.com/2014/07/23/boeings-new-777x-designs-intensify-the-race-for-space-on-airlines/#1 |archive-date=December 30, 2016 |access-date=August 8, 2014 |work=Skift}} The 777X will feature cabin design details requiring structural changes that were originally introduced on the Boeing 787 Dreamliner: larger windows, higher ceilings, more humidity and lowered cabin altitude to {{cvt|6000|ft|m}}.{{cite web |author=Shankland |first=Stephen |date=July 15, 2014 |title=Boeing's 777X plans: Big windows, lots of air, and robot manufacturing |url=http://www.cnet.com/news/boeings-777x-plans-big-windows-lots-of-air-and-robot-manufacturing/ |url-status=live |archive-url=https://web.archive.org/web/20160314182141/http://www.cnet.com/news/boeings-777x-plans-big-windows-lots-of-air-and-robot-manufacturing/ |archive-date=March 14, 2016 |access-date=July 18, 2014 |work=CNET}} Its flight deck is similar to the 787 cockpit with large displays and head-up displays, controls for the folding wingtips, and touchscreens replacing cursor control devices. Windows are dimmable but have an available option for the standard window shades.

For the longer 777-9, replacing the engines should improve fuel consumption by 10%, with the longer, carbon-fiber wings adding an estimated 7% improvement. As 4 to 5% of fuel savings is lost from the 12 tons heavier basic structure of the larger airliner, the net fuel efficiency gain is projected to be 12 to 13%. Ten-abreast seating instead of nine with a longer fuselage enable a reduction in fuel burn per seat of 20% compared to the 365-seat 777-300ER. The longer-range, 355-seat 777-8 should have a 13% improvement in fuel consumption with 10 fewer seats than the -300ER.{{cite news |author=Norris |first1=Guy |last2=Anselmo |first2=Joe |date=October 31, 2016 |title=777X Production Investments Bolster Boeing |url=http://aviationweek.com/commercial-aviation/777x-production-investments-bolster-boeing |url-status=live |archive-url=https://web.archive.org/web/20161206085502/http://aviationweek.com/commercial-aviation/777x-production-investments-bolster-boeing |archive-date=December 6, 2016 |access-date=November 30, 2016 |work=Aviation Week & Space Technology}} Boeing forecast a 33% better cost per seat than the 747-400 and 13% better than the 777-300ER.{{cite news |author=Ostrower |first=Jon |date=Jan 28, 2020 |title=Boeing needs 777X for far more than just fighting Airbus |url=https://theaircurrent.com/aircraft-development/boeing-needs-777x-for-far-more-than-just-fighting-airbus/ |url-status=live |archive-url=https://web.archive.org/web/20200130174732/https://theaircurrent.com/aircraft-development/boeing-needs-777x-for-far-more-than-just-fighting-airbus/ |archive-date=January 30, 2020 |access-date=January 30, 2020 |work=The Air Current}}

Its maximum takeoff weight is targeted for {{cvt|775,000|lb|t|1}} like the 777-300ER but Boeing hopes to have at least a {{cvt|10,000|lb|t|1}} margin at introduction. Boeing predicts the -8 to be 4% more fuel efficient and cost effective than the A350-1000, while the -9 would be 12% more fuel efficient and 11% more cost effective.{{cite web |url= http://www.boeing.com/commercial/777x/by-design/#/777-8-characteristics |title= 777X Technical Specs |publisher= Boeing |access-date= September 11, 2017 |archive-date= September 11, 2017 |archive-url= https://web.archive.org/web/20170911161543/http://www.boeing.com/commercial/777x/by-design/#/777-8-characteristics |url-status= live}} Lufthansa, when it ordered both, stated the Airbus A350-900 and the 777-9X will consume an average of 2.9 L/100 km per passenger.{{cite press release |date= September 19, 2013 |title= Modern, Quiet and Environmentally Efficient: Lufthansa Group Orders 59 Ultra-Modern Wide-Body Boeing 777-9X and Airbus A350-900 Aircraft |url= http://www.lufthansa.com/mediapool/pdf/14/media_886835514.pdf |url-status=dead |archive-url= https://web.archive.org/web/20171023230602/http://www.lufthansa.com/mediapool/pdf/14/media_886835514.pdf |archive-date=23 October 2017 |publisher= Lufthansa}}

The 777-8 is a shortened derivative of the 777-9, initially specified as {{cvt|229|ft|1}} long, between the {{cvt|209|ft|1|in|1}} 777-200 and {{cvt|242|ft|4|in|1}} 777-300. It would seat typically 395 passengers with a range of 8,745 nmi (16,170 km; {{cvt|8730|nmi|mi|disp=output only}}).{{cite press release |url= https://investors.boeing.com/investors/investor-news/press-release-details/2020/New-Boeing-777X-Completes-Successful-First-Flight/default.aspx |title= New Boeing 777X Completes Successful First Flight |date= January 25, 2020 |publisher= Boeing |access-date= January 26, 2020 |archive-date= January 26, 2020 |archive-url= https://web.archive.org/web/20200126091019/https://investors.boeing.com/investors/investor-news/press-release-details/2020/New-Boeing-777X-Completes-Successful-First-Flight/default.aspx |url-status= live}} It would succeed the ultra-long-range 777-200LR{{cite news |url= https://www.flightglobal.com/news/articles/boeing-reveals-ultra-long-range-777-8x-387108/ |title= Boeing reveals ultra-long-range 777-8X |work= FlightGlobal |date= June 14, 2013 |access-date= September 20, 2016 |archive-date= October 2, 2016 |archive-url= https://web.archive.org/web/20161002123536/https://www.flightglobal.com/news/articles/boeing-reveals-ultra-long-range-777-8x-387108/ |url-status= live}} and compete with the Airbus A350-1000.{{cite web |url= http://www.aspireaviation.com/2013/05/27/boeing-lost-grounds-all-fronts/ |title= Boeing To Make Up Lost Grounds On All Fronts |work= Aspire Aviation |date= May 27, 2013 |access-date= June 20, 2013 |archive-date= April 9, 2016 |archive-url= https://web.archive.org/web/20160409050302/http://www.aspireaviation.com/2013/05/27/boeing-lost-grounds-all-fronts/ |url-status= live}}

Production of the -8 was expected to follow the -9 around two years later. It was expected to be the basis of a freighter version which would be available 18 to 24 months after the introduction of the -8. The 777-8 should feature a {{cvt|13,000|lb|t}} higher MTOW over the {{cvt|775,000|lb|t}} of the 777-9, for an improved range from {{cvt|8,690 to 9,460|nmi|km}}.{{cite news |author=Ostrower |first=Jon |date=May 30, 2019 |title=Boeing chases range frontier on 787 and 777X to win Air New Zealand, Qantas deals |url=https://theaircurrent.com/aircraft-development/boeing-chases-range-frontier-on-787-and-777x-to-win-air-new-zealand-qantas-deals/ |url-status=live |archive-url=https://web.archive.org/web/20190611204841/https://theaircurrent.com/aircraft-development/boeing-chases-range-frontier-on-787-and-777x-to-win-air-new-zealand-qantas-deals/ |archive-date=June 11, 2019 |access-date=December 4, 2019 |work=The air current}}

Due to the Boeing 737 MAX groundings and the delayed first flight of the 777-9, in 2019 Boeing pushed back design and development of the 777-8 until at least 2021, for first deliveries expected in 2023 or beyond. The delays were not expected to affect Boeing's participation in Qantas' Project Sunrise, for which it has proposed a 777-8 variant.{{cite news |author=Norris |first1=Guy |last2=Schofield |first2=Adrian |date=Aug 15, 2019 |title=Boeing Delays Development Of Longer-Range 777X Variant |url=https://aviationweek.com/commercial-aviation/boeing-delays-development-longer-range-777x-variant |url-status=live |archive-url=https://web.archive.org/web/20210527124117/https://aviationweek.com/air-transport/boeing-delays-development-longer-range-777x-variant |archive-date=May 27, 2021 |access-date=August 15, 2019 |work=Aviation Week Network}} Boeing also proposed an interim solution to Qantas, assumed to comprise a 777-9 with auxiliary fuel tanks and reduced seating capacity.{{cn|date=January 2023}} However, Qantas subsequently preferred the Airbus A350-1000 for this project.{{Cite press release |url=https://www.qantasnewsroom.com.au/media-releases/qantas-update-on-project-sunrise/ |title=Qantas Update on Project Sunrise |website=Qantas News Room|date=December 13, 2019 |access-date=May 1, 2022}} The -8 would also fill the niche market for an aircraft capable of flying with a full payload from hubs in the Gulf states to the West Coast of the United States. It could, however, be cancelled if customers find the -9 acceptable for these routes.{{cite news |last1=Kingsley-Jones |first1=Max |title=ANALYSIS: How shelving of 777-8 could prompt Boeing rethink |url= https://www.flightglobal.com/news/articles/analysis-how-shelving-of-777-8-could-prompt-boeing-460592/ |work=Flightglobal.com |date=September 9, 2019 |access-date=September 9, 2019 |archive-date=September 10, 2019 |archive-url= https://web.archive.org/web/20190910220556/https://www.flightglobal.com/news/articles/analysis-how-shelving-of-777-8-could-prompt-boeing-460592/ |url-status=live}}

In August 2023, Boeing announced an increase in the length of the passenger -8 to {{cvt|232|ft|6|in}}, the same as the freighter version.{{cite news |last1=Perry |first1=Dominic |title=Boeing stretches 777-8 passenger jet to match freighter's fuselage |url=https://www.flightglobal.com/air-transport/boeing-stretches-777-8-passenger-jet-to-match-freighters-fuselage/154453.article |work=Flight Global |date=August 8, 2023 |language=en}}

In June 2019, Qatar Airways urged Boeing to develop a 777X-based freighter to replace its existing 777Fs which were first delivered in 2009. Boeing confirmed that discussions were under way to define a timeline for a freighter variant,{{cite news |last1=Hemmerdinger |first1=Jon |title=Qatar offers to be launch customer for a 777X freighter |url= https://www.flightglobal.com/news/articles/paris-qatar-offers-to-be-launch-customer-for-a-777x-459186/ |work=Flightglobal |date=19 June 2019 |access-date=June 20, 2019 |archive-date=June 20, 2019 |archive-url= https://web.archive.org/web/20190620070045/https://www.flightglobal.com/news/articles/paris-qatar-offers-to-be-launch-customer-for-a-777x-459186/ |url-status=live}} expected to be based on the 777-8 airframe. In July 2021, Boeing CEO David Calhoun viewed a freighter version as a logical next aircraft program to comply with emerging ICAO aircraft emission standards.{{cite news |author=Hemmerdinger |first=Jon |date=28 July 2021 |title=Boeing needs new emissions-compliant freighter, 777X variant is 'logical' choice: CEO |url=https://www.flightglobal.com/airframers/boeing-needs-new-emissions-compliant-freighter-777x-variant-is-logical-choice-ceo/144818.article |work=Flightglobal}} On January 31, 2022, Boeing officially launched the 777-8 Freighter, with an order from Qatar Airways for 34 aircraft and 16 options, with deliveries expected to begin in 2027.{{Cite web |title= Boeing Launches 777-8 Freighter to Serve Growing Demand for Cargo, Enhanced Environmental Performance |url= https://boeing.mediaroom.com/2022-01-31-Boeing-Launches-777-8-Freighter-to-Serve-Growing-Demand-for-Cargo,-Enhanced-Environmental-Performance |date= 31 January 2022 |publisher= Boeing |archive-url= https://web.archive.org/web/20220131220250/https://boeing.mediaroom.com/2022-01-31-Boeing-Launches-777-8-Freighter-to-Serve-Growing-Demand-for-Cargo,-Enhanced-Environmental-Performance|archive-date= 31 January 2022}}

File:Boeing 777X at Dubai Airshow 2021.jpg.]]

The 777-9 is stretched by three extra seat rows and flies {{cvt|250|nmi}} farther than the 777-300ER with about the same weight. It will seat around 426 passengers with a range of 7,285 nmi (13,500 km; {{cvt|7285|nmi|mi|disp=output only}}). Boeing froze its design in August 2015 and was to start first assembly in 2017. The first flight of the 777-9 was on Saturday, January 25, 2020.

Its operating empty weight grew from the 777-300ER's {{cvt|373500|lb|kg|-2}} to {{cvt|400000|lb|kg|-2}}.{{cite web |author=Norris |first1=Guy |last2=Flottau |first2=Jens |date=November 8, 2016 |title=Airbus, Boeing Deciding Larger A350, 777X Versions |url=http://aviationweek.com/commercial-aviation/airbus-boeing-deciding-larger-a350-777x-versions |url-status=live |archive-url=https://web.archive.org/web/20161110041734/http://aviationweek.com/commercial-aviation/airbus-boeing-deciding-larger-a350-777x-versions |archive-date=November 10, 2016 |access-date=November 9, 2016 |work=Aviation week}} In 2014, Aspire Aviation had reported that according to Boeing sources, the operating empty weight of a 777-9X in a 4-class, 300-seat configuration was {{cvt|415000|lb|kg|-2}}.{{cite web |author=Tsang |first=Daniel |date=July 2014 |title=Airbus, Boeing in game of thrones for widebody dominance |url=http://www.aspireaviation.com/wp-content/uploads/2014/07/Boeing-Airbus-widebody-battle.pdf |url-status=live |archive-url=https://web.archive.org/web/20171023174322/http://www.aspireaviation.com/wp-content/uploads/2014/07/Boeing-Airbus-widebody-battle.pdf |archive-date=October 23, 2017 |access-date=May 10, 2017 |work=Aspire Aviation}}{{rp|p=10}} The same sources identified the manufacturer’s empty weight at {{cvt|362000|lb|kg|-2}}.{{rp|p=10}}

Listed at $426 million in 2018, valuation specialist Avitas estimated the -9 purchase price with typical discounts would be around $200 million (in 2018 dollars).

The 777-9 is to supersede the {{cvt|250|ft|2|in}} Boeing 747-8 as the longest airliner. It is {{cvt|9.4|ft|1}} longer than the -300ER for a {{cvt|251|ft|9|in|1}} length.

Boeing has proposed stretching the -9 by four rows of seats to accommodate 450 passengers in a 777-10X variant to compete with the Airbus A380 and a potential stretch of the A350. The company has approached several airlines including Emirates, the largest operator of both the 777 and the A380.{{cite news |title= Boeing Mulls Stretching 777 to Knock Out Airbus A380 |url= https://www.bloomberg.com/news/articles/2016-06-30/boeing-said-to-mull-stretching-777-to-knock-out-airbus-a380-jet |agency= Bloomberg |date= June 30, 2016 |access-date= March 5, 2017 |archive-date= April 7, 2017 |archive-url= https://web.archive.org/web/20170407022446/https://www.bloomberg.com/news/articles/2016-06-30/boeing-said-to-mull-stretching-777-to-knock-out-airbus-a380-jet |url-status= live}} The A380 seats between 489 and 615 passengers. The potential {{convert|263|ft|m}} long 777-10X ({{convert|12|ft|m|disp=or|abbr=on}} more) could compete against a hypothetical stretch of the A350-1000.{{cite news |author=Ostrower |first=Jon |date=November 7, 2016 |title=Singapore Airlines shops for world's longest jet |url=https://money.cnn.com/2016/11/07/news/companies/singapore-airbus-boeing-campaign/ |url-status=live |archive-url=https://web.archive.org/web/20200814170929/https://money.cnn.com/2016/11/07/news/companies/singapore-airbus-boeing-campaign/ |archive-date=August 14, 2020 |access-date=August 3, 2020 |work=CNN Money}} Boeing confirmed that the 777 stretch is feasible if there is interest.{{cite news |author=Trimble |first=Stephen |date=July 10, 2016 |title=Boeing confirms technical feasibility of '777-10' |url=https://www.flightglobal.com/news/articles/farnborough-boeing-confirms-technical-feasibility-o-427165/ |url-status=live |archive-url=https://web.archive.org/web/20190902075001/https://www.flightglobal.com/news/articles/farnborough-boeing-confirms-technical-feasibility-o-427165/ |archive-date=September 2, 2019 |access-date=December 11, 2018 |work=Flightglobal}}

On December 10, 2018, Boeing launched Boeing Business Jet variants at the Middle East Business Aviation Association Show. The BBJ 777-8 offers a range of 11,645 nautical miles (21,570 km) and a 3,256 sq ft (302.5 sq m) cabin, while the BBJ 777-9 provides a 3,689 sq ft (342.7 sq m) cabin and a range of 11,000 nautical miles (20,370 km).{{cite press release |url= https://boeing.mediaroom.com/2018-12-10-Boeing-Launches-Longest-Range-Business-Jet-Ever-with-BBJ-777X |title= Boeing Launches Longest-Range Business Jet Ever with BBJ 777X |date= December 10, 2018 |publisher= Boeing |access-date= December 10, 2018 |archive-date= March 8, 2021 |archive-url= https://web.archive.org/web/20210308154040/https://boeing.mediaroom.com/2018-12-10-Boeing-Launches-Longest-Range-Business-Jet-Ever-with-BBJ-777X |url-status= live}}

{{See also|List of Boeing 777X orders and deliveries}}

On September 19, 2013, Lufthansa became the first airline to select the 777X when it placed an order for 34 777-9 airliners, but the order was later changed to 20 firm orders and 14 options.{{cite web |title=Lufthansa Switches Boeing 777 Orders to Options in Fleet Rethink |url=https://www.bloomberg.com/news/articles/2019-11-07/lufthansa-switches-boeing-777-orders-to-options-in-fleet-rethink |website=Bloomberg.com |publisher=Bloomberg News |access-date=6 May 2024 |language=English |date=8 November 2019}} This was followed in May 2022 with an announcement for an order of seven 777-8 Freighters destined for Lufthansa Cargo operations.{{Cite web |last=Wert |first=Jakob |date=2022-05-09 |title=Lufthansa orders Boeing 777X freighters, additional 787 and 777F |url=https://www.ifn.news/posts/lufthansa-orders-boeing-777x-freighters-additional-787-and-777f/ |access-date=2022-05-10 |website=International Flight Network |language=en-GB}}

In December 2013, Hong Kong-based Cathay Pacific ordered 21 777-9 airliners with deliveries expected from 2021,{{cite press release |title= Cathay Pacific places order for 21 Boeing 777-9X aircraft |url= https://www.cathaypacific.com/cx/en_HK/about-us/press-room/press-release/2013/Cathay-pacific-places-order-for-21-boeing777-9x-aircraft-deliveries-to-commence-in-2021.html |publisher= Cathay Pacific |date= December 20, 2013 |access-date= October 23, 2017 |archive-url= https://web.archive.org/web/20171024043201/https://www.cathaypacific.com/cx/en_HK/about-us/press-room/press-release/2013/Cathay-pacific-places-order-for-21-boeing777-9x-aircraft-deliveries-to-commence-in-2021.html |archive-date= October 24, 2017 |url-status= dead}} but they will now not join Cathay's fleet before 2025.{{Cite web |date=2024-03-18 |title=Cathay Pacific still expects its first 777-9s in 2025 |url=https://www.aerotime.aero/articles/cathay-pacific-777-9s-recovery-continues |access-date=2024-05-20 |language=en-US}}

In July 2014, Emirates, the launch customer, finalized its order for 150 777X aircraft, consisting of 115 777-9s and 35 777-8s.{{cite news |url= http://www.flightglobal.com/news/articles/emirates-finalises-order-for-150-777x-jets-401198/ |title= Emirates finalises order for 150 777X jets |author= Kaminski-Morrow, David |work= Flight Global |date= July 9, 2014 |access-date= January 6, 2015 |archive-date= March 6, 2016 |archive-url= https://web.archive.org/web/20160306214149/https://www.flightglobal.com/news/articles/emirates-finalises-order-for-150-777x-jets-401198/ |url-status= live}} On July 16, Qatar Airways finalized its order for 50 777-9 aircraft, with purchase rights for 50 more 777-9s.{{cite press release |url= http://boeing.mediaroom.com/2014-07-16-Boeing-Qatar-Airways-Finalize-Order-for-50-777Xs |title= Boeing, Qatar Airways Finalize Order for 50 777Xs |publisher= Boeing |date= July 16, 2014 |access-date= October 13, 2014 |archive-date= March 4, 2016 |archive-url= https://web.archive.org/web/20160304051609/http://boeing.mediaroom.com/2014-07-16-Boeing-Qatar-Airways-Finalize-Order-for-50-777Xs |url-status= live}} On July 31, Japan's All Nippon Airways finalized an order for 20 Boeing 777-9s.{{cite press release |url= http://boeing.mediaroom.com/2014-07-31-Boeing-All-Nippon-Airways-Finalize-Order-for-40-Widebody-Airplanes |title= All Nippon Airways Finalize Order for 40 Widebody Airplanes |publisher= Boeing |date= July 31, 2014 |access-date= October 13, 2014 |archive-date= November 29, 2016 |archive-url= https://web.archive.org/web/20161129190324/http://boeing.mediaroom.com/2014-07-31-Boeing-All-Nippon-Airways-Finalize-Order-for-40-Widebody-Airplanes/ |url-status= live}}

In December 2016, Iran Air signed an agreement with Boeing that included 15 777-9 aircraft,{{cite press release |url= http://boeing.mediaroom.com/2016-12-11-Boeing-Iran-Air-Announce-Agreement-for-80-Airplanes |title=Boeing, Iran Air Announce Agreement for 80 Airplanes |date=December 11, 2016 |publisher=Boeing |access-date=January 22, 2017 |archive-date=January 12, 2017 |archive-url= https://web.archive.org/web/20170112154624/http://boeing.mediaroom.com/2016-12-11-Boeing-Iran-Air-Announce-Agreement-for-80-Airplanes |url-status=live}} but this agreement was effectively cancelled when the United States withdrew from the Iran Nuclear Deal in May 2018.{{cite news |author=Field |first=James |date=May 9, 2018 |title=U.S Officially Withdraws From Iran Nuclear Deal – $38 billion of Orders Canceled |work=Airways International |url= https://airwaysmag.com/industry/us-officially-withdraws-from-iran-nuclear-deal-38-billion-orders-canceled/ |url-status=live |access-date= |archive-date=June 23, 2018 |archive-url= https://web.archive.org/web/20180623112810/https://airwaysmag.com/industry/us-officially-withdraws-from-iran-nuclear-deal-38-billion-orders-canceled/}}

In February 2017, Singapore Airlines signed a letter of intent with Boeing for 20 777-9 and 19 787-10 airliners; this was firmed in June 2017.{{Cite news |url= https://www.flightglobal.com/news/articles/boeing-update-indicates-firming-of-sia-deal-for-777x-438813/ |title= Boeing update indicates firming of SIA deal for 777Xs and 787-10s |work= Flight Global |date= June 27, 2017 |access-date= June 27, 2017 |archive-date= June 27, 2017 |archive-url= https://web.archive.org/web/20170627155054/https://www.flightglobal.com/news/articles/boeing-update-indicates-firming-of-sia-deal-for-777x-438813/ |url-status= live}} In June 2017, the three Persian Gulf carriers (Emirates, Etihad Airways and Qatar Airways) held 235 orders, {{#expr:235/3.4round0}}% of the 340 commitments, which were less financially secure than previously. Etihad's widespread investing strategy had backfired as it reduced feed sources, making it harder to fill the orders for the 777X. Emirates' demand had been slowing and it was considering deferral of deliveries, having the smallest sovereign wealth fund backing of the Gulf carriers. Qatar Airways was facing economic concerns and was suffering from a diplomatic crisis with its neighbors.{{cite news |author=Bhaskara |first1=Vinay |last2=Sloan |first2=Chris |date=June 8, 2017 |title=Boeing 777X Program Perched Precariously Despite Strong Execution |work=Airways Magazine |url= https://airwaysmag.com/airlines/boeing-777x-trouble-strong-execution/ |url-status=live |access-date= |archive-date=November 2, 2017 |archive-url= https://web.archive.org/web/20171102014326/https://airwaysmag.com/airlines/boeing-777x-trouble-strong-execution/}}

After a nearly $2 billion loss in 2016, Etihad had to cut routes and shrink its fleet and thus is considering canceling or deferring its orders, preferring to incur cancellations penalties rather than recurring losses from overcapacity. On February 14, 2019, it was reported that Etihad would take only 6 of the 25 777X airliners it had originally ordered.{{cite news |url= https://www.thenational.ae/business/aviation/etihad-restructures-aircraft-orders-after-conclusion-of-talks-with-airbus-and-boeing-1.825597 |title= Etihad restructures aircraft orders after conclusion of talks with Airbus and Boeing |date= Feb 14, 2019 |work= The National (Abu Dhabi) |access-date= September 2, 2019 |archive-date= September 2, 2019 |archive-url= https://web.archive.org/web/20190902055147/https://www.thenational.ae/business/aviation/etihad-restructures-aircraft-orders-after-conclusion-of-talks-with-airbus-and-boeing-1.825597 |url-status= live}}

On February 28, 2019, British Airways parent International Airlines Group ordered up to 42 777-9, 18 firm and 24 options, valued at up to $18.6 billion (~${{Format price|{{Inflation|index=US-GDP|value=18600000000|start_year=2019}}}} in {{Inflation/year|US-GDP}}), to replace its 747-400s.{{cite press release |url= https://boeing.mediaroom.com/2019-02-28-Boeing-Signs-Deal-for-Up-to-42-777X-Airplanes-with-International-Airlines-Group |title= Boeing Signs Deal for Up to 42 777X Airplanes with International Airlines Group |date= February 28, 2019 |publisher= Boeing |access-date= February 28, 2019 |archive-date= February 28, 2019 |archive-url= https://web.archive.org/web/20190228134239/https://boeing.mediaroom.com/2019-02-28-Boeing-Signs-Deal-for-Up-to-42-777X-Airplanes-with-International-Airlines-Group |url-status= live}}

On November 7, 2019, Lufthansa stated it had converted 14 orders into options, leaving 6 firm commitments, after having negotiated a change as part of its order for 20 787s.{{cite news |author=Massy-Beresford |first1=Helen |last2=Flottau |first2=Jens |date=November 11, 2019 |title=Will Europe's Legacy Carriers' Plans Help Weather Economic Downturn? |work=Aviation Week & Space Technology |url= https://aviationweek.com/commercial-aviation/will-europe-s-legacy-carriers-plans-help-weather-economic-downturn |url-status=live |access-date= |archive-date=May 27, 2021 |archive-url= https://web.archive.org/web/20210527124118/https://aviationweek.com/air-transport/will-europes-legacy-carriers-plans-help-weather-economic-downturn}}

On November 20, 2019, Emirates reduced its order total to 115 in exchange for ordering 30 Boeing 787-9s, while remaining the largest 777X customer.{{Cite web |url= https://www.businessinsider.com/emirates-boeing-787-dreamliner-777x-dubai-airshow-2019-11 |title=Boeing's Dreamliner deal with Emirates has a major downside for the plane maker |first=David |last=Slotnick |website=Business Insider |access-date=December 13, 2019 |archive-date=November 21, 2019 |archive-url= https://web.archive.org/web/20191121144820/https://www.businessinsider.com/emirates-boeing-787-dreamliner-777x-dubai-airshow-2019-11 |url-status=live}}{{cite news |url= https://www.forbes.com/sites/marisagarcia/2019/11/20/emirates-adjusts-boeing-orders-firming-up-787s-and-reducing-777x-commitment-amidst-delays |title= Emirates Cuts Boeing 777X Order Amid Delays, Firms Up 787 Buy |date= Nov 20, 2019 |work= Forbes |access-date= November 21, 2019 |archive-date= November 21, 2019 |archive-url= https://web.archive.org/web/20191121133103/https://www.forbes.com/sites/marisagarcia/2019/11/20/emirates-adjusts-boeing-orders-firming-up-787s-and-reducing-777x-commitment-amidst-delays/ |url-status= live}}

In January 2021, Boeing reduced its sales expectation for the program from 400 to 350 aircraft.{{cite news |author=Hemmerdinger |first=Jon |date=27 January 2021 |title=Boeing trims 777X production quantity expectation by 50 jets |work=FlightGlobal |url= https://www.flightglobal.com/airframers/boeing-trims-777x-production-quantity-expectation-by-50-jets/142158.article |url-status=live |access-date= |archive-date=January 28, 2021 |archive-url= https://web.archive.org/web/20210128010850/https://www.flightglobal.com/airframers/boeing-trims-777x-production-quantity-expectation-by-50-jets/142158.article}} Boeing reclassified 118 orders from firm to uncertain under the ASC 606 accounting rule, for 191 orders down from 309 previously.{{cite news |author=Hamilton |first1=Scott |last2=Valery |first2=Vincent |date=February 1, 2021 |title=Exclusive: Boeing shifts 118 777 orders to "iffy" under accounting rule; 191 firm orders remain |work=Leeham News |url= https://leehamnews.com/2021/02/01/exclusive-boeing-shifts-118-777-orders-to-iffy-under-accounting-rule-191-firm-orders-remain/ |url-status=live |access-date= |archive-date=February 2, 2021 |archive-url= https://web.archive.org/web/20210202113843/https://leehamnews.com/2021/02/01/exclusive-boeing-shifts-118-777-orders-to-iffy-under-accounting-rule-191-firm-orders-remain/}}{{Cite news |last= |first= |date=2021-02-02 |title=Boeing says 118 orders for 777X no longer firm under accounting rules |work=Reuters |url= https://www.reuters.com/article/us-boeing-orders-idUSKBN2A20A1 |url-status=live |access-date=2021-02-02 |archive-date=February 2, 2021 |archive-url= https://web.archive.org/web/20210202084600/https://www.reuters.com/article/us-boeing-orders-idUSKBN2A20A1}} On February 9, Singapore Airlines announced that they had converted an order for 14 Boeing 787-10 Dreamliners into 11 Boeing 777-9s; bringing its order for the 777-9 to 31.{{cn|date=June 2024}}

On January 31, 2022, Qatar Airways became the launch customer for the 777X Freighter program, with an order of up to 50 Boeing 777-8 Freighters, expanding its commitment to the Boeing 777X family. In March 2022, Ethiopian Airlines signed a memorandum of understanding for five 777-8Fs.{{Cite web|url=https://boeing.mediaroom.com/2022-03-04-Boeing-and-Ethiopian-Airlines-Sign-Memorandum-of-Understanding-for-New-777-8-Freighter|title=Boeing and Ethiopian Airlines Sign Memorandum of Understanding for New 777-8 Freighter|website=MediaRoom}}

On February 11, 2023, Air India signed a letter of intent (LOI) to buy 10 Boeing 777-9s as part of a combined 470 aircraft order from both Airbus and Boeing.{{Cite news |last1=Shah |first1=Aditi |last2=Hepher |first2=Tim |date=2023-02-11 |title=Air India seals record order for about 500 jets from Airbus, Boeing |language=en |work=Reuters |url=https://www.reuters.com/business/aerospace-defense/air-india-agrees-buy-250-jets-airbus-part-jumbo-order-sources-2023-02-10/ |access-date=2023-02-11}}{{cite web |url=https://aviationweek.com/air-transport/aircraft-propulsion/air-india-confirms-orders-470-airbus-boeing-aircraft |title=Air India Confirms Orders for 470 Airbus and Boeing Aircraft |website= Aviation Week}}{{cite press release |url=https://boeing.mediaroom.com/2023-02-14-Air-India-Selects-Up-to-290-Boeing-Jets-to-Serve-Its-Strategy-for-Sustainable-Growth |title=Air India Selects Up to 290 Boeing Jets to Serve Its Strategy for Sustainable Growth |website=Boeing |date=2023-02-14}} The airline confirmed the order at the Paris Air Show on June 20, 2023, which included 10 777Xs, 20 787 Dreamliners and 190 737 MAX jets with options for further 50 737 MAXs and 20 787 Dreamliners. It was Boeing's largest single order in South Asia and highlighted its 90-year partnership with Air India.{{cite press release |url=https://boeing.mediaroom.com/2023-06-20-Air-India-Finalizes-Order-for-Up-to-290-Boeing-Single-Aisle-and-Widebody-Jets |title=Air India Finalizes Order for Up to 290 Boeing Single-Aisle and Widebody Jets |website=Boeing |date=2023-06-20}} On November 13, 2023, at the 2023 Dubai Airshow Emirates ordered an additional 90 777Xs, including 55 of the 777-9 and 35 of the 777-8, bringing the airline's total order to 205 777Xs.{{cn|date=June 2024}}

On March 5, 2024, Ethiopian Airlines announced an agreement with Boeing for eight 777-9s with options for 12 more.Hemmerdinger, Jon. [https://www.flightglobal.com/airframers/ethiopian-commits-to-purchase-eight-boeing-777-9s/157261.article "Ethiopian commits to purchase eight Boeing 777-9s"]. Flight Global, March 5, 2024. Quote: "Boeing and Ethiopian Airlines announced today an agreement... to purchase eight 777-9 passenger airplanes..." On December 19, 2024, China Airlines announced plans to order ten 777-9s to replace their existing 777-300ERs along with four 777-8F to supplement their freighter fleet.{{cite web |title=China Airlines Announces Plan for New Fleet of 24 Passenger and Cargo Aircraft |website=China Airlines |date=November 28, 2024 |url=https://www.china-airlines.com/us/en/discover/news/press-release/20241219-2 |access-date=December 25, 2024}}

In March 2025, shortly after the major rebrand of the Korean Air, it is reported that the airline has finalized an order of 20 777-9 aircraft as part of an 40-aircraft deal with Boeing and GE Aerospace, it is the result of the memorandum of understanding (MoU) which was signed during 2024 Farnborough International Airshow. The deal also includes 8 spare engines plus two options and a maintenance service contract for the General Electric GE9X engines.{{Cite web |last=Derby |first=Kevin |date=2025-03-21 |title=Korean Air Nears New $25 Billion Deal with Boeing for 777X and 787-10 |url=https://aviationa2z.com/index.php/2025/03/21/korean-air-nears-boeing-order/ |access-date=2025-03-23 |website=Aviation A2Z |language=en-US}}{{Cite web |last=Molyneaux |first=Ian |date=2025-03-23 |title=Korean Air to finalize MoU for 20 Boeing 777-9s, 20 787-10s |url=https://www.aerotime.aero/articles/korean-air-boeing-mou-order-ge-aerospace |access-date=2025-03-25 |website=www.aerotime.aero |language=en-US}}

{{Overly detailed|section|nosplit=1|details=per WP:AIRMOS, this section should cover the specifications of only a single variant|date=June 2025}}

{{Portal|Aviation}}

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}}

{{notelist}}

{{reflist}}

• {{Cite web |url= https://www.boeing.com/commercial/customers/lufthansa/lufthansa-will-be-launch-customer-for-new-boeing-777x.page |title= Lufthansa will be a launch customer for new Boeing 777X aircraft program |publisher= Boeing}}
• {{cite web |url= http://www.boeing.com/commercial/777x/?cm_re=March_2015-_-Roadblock-_-777X#/technical-specs |title= Boeing 777X – Technical Information |publisher= Boeing}}
• {{cite news |url=http://www.flightglobal.com/news/articles/next-generation-777-comes-into-focus-362065/ |title=Next generation 777 comes into focus |author=Ostrower |first=Jon |work=Flight International |date=September 14, 2011}} or {{cite news |url=http://www.flightglobal.com/blogs/flightblogger/2011/09/boeings-777-upgrades-come-into.html |archive-url=https://web.archive.org/web/20130406184237/http://www.flightglobal.com/blogs/flightblogger/2011/09/boeings-777-upgrades-come-into.html |url-status=dead |archive-date=April 6, 2013 |title=Boeing's 777-9X comes into focus with a massive CFRP wing |date=September 14, 2011 |work=Flightblogger |author=Ostrower |first=Jon}}
• {{cite news |url=http://www.aspireaviation.com/2011/09/14/new-boeing-777x-likely-to-be-a-highly-efficient-derivative/ |title=New Boeing 777X likely to be a highly efficient derivative |work=Aspire Aviation |author=Tsang |first=Daniel |date=September 14, 2011}}
• {{cite news |url=http://www.aspireaviation.com/2012/02/09/boeing-develops-777x-to-challenge-airbus-a350/ |title=Boeing develops 777X to challenge Airbus A350 |work=Aspire Aviation |author=Tsang |first=Daniel |date=February 9, 2012}}
• {{cite news |url=http://www.flightglobal.com/news/articles/boeing-studies-ultra-long-range-777-8lx-concept-368176/ |title=Boeing studies ultra long-range 777-8LX concept |author=Ostrower |first=Jon |work=Flightglobal |date=February 13, 2012}}
• {{cite news |url=http://www.flightglobal.com/news/articles/boeing-homes-in-on-late-2012-launch-for-777-successor-369241/ |title=Boeing homes in on late-2012 launch for 777 successor |author=Ostrower |first=Jon |work=Flight International |date=March 7, 2012}}
• {{cite news |url=http://www.flightglobal.com/news/articles/ge-plans-10-fuel-burn-improvement-for-ge9x-engine-369242/ |title=GE plans 10% fuel burn improvement for GE9X engine |author=Ostrower |first=Jon |work=Flight International |date=March 7, 2012}}
• {{cite news |url=http://www.ainonline.com/aviation-news/paris-air-show/2013-06-16/ge-pushes-envelope-ge9x-new-boeing-777 |title=GE Pushes Envelope With GE9X for New Boeing 777 |author=Alcock |first=Charles |date=June 16, 2013 |work=Aviation International News |access-date=November 20, 2013 |archive-date=October 21, 2014 |archive-url=https://web.archive.org/web/20141021213858/http://www.ainonline.com/aviation-news/paris-air-show/2013-06-16/ge-pushes-envelope-ge9x-new-boeing-777 |url-status=dead}}
• {{cite news |url=https://www.reuters.com/article/us-airbus-boeing-minijumbo-insight-idUSBRE9620TJ20130703 |title=Elbows fly in Airbus and Boeing battle over mini-jumbos |work=Reuters |date=July 3, 2013 |author=Hepher |first=Tim}}
• {{Cite video |title= The New GE9X Engine |url= https://www.youtube.com/watch?v=qVVj2ddb-eQ |date= June 17, 2013 |author= General Electric}}
• {{cite press release |url= http://boeing.mediaroom.com/2013-09-19-Boeing-Statement-on-Lufthansa-Selection-of-Boeing-777X-for-Future-Long-Haul-Fleet |title= Boeing Statement on Lufthansa Selection of Boeing 777X for Future Long-Haul Fleet |publisher= Boeing |date= September 19, 2013}}
• {{cite news |author=Norris |first=Guy |date=November 17, 2013 |title=Boeing Launches 777X in Dubai Order Boom |url=http://aviationweek.com/commercial-aviation/boeing-launches-777x-dubai-order-boom |work=Aviation Week |access-date=October 23, 2017 |archive-date=October 24, 2017 |archive-url=https://web.archive.org/web/20171024051426/http://aviationweek.com/commercial-aviation/boeing-launches-777x-dubai-order-boom |url-status=dead}}
• {{cite news |date= November 17, 2013 |title= Dubai Air Show: Boeing Leads Order Books Race |url= https://www.bbc.co.uk/news/business-24978226 |publisher= BBC |work= Business}}
• {{cite news |author=Wilhelm |first=Steve |date=November 13, 2013 |title=Boeing Launches 777X with Orders for 259 Jets Worth $95B |url=http://www.bizjournals.com/seattle/news/2013/11/17/boeing-launches-777x-with-orders-for.html |journal=Puget Sound Business Journal |location=Seattle, Washington |publisher=American City Business Journals}}
• {{cite web |url= http://www.boeing.com/farnborough2014/pdf/BCA/777X-Fact%20Sheet-June2014.pdf |title= Boeing 777X fact sheet |date= June 2014 |publisher= Boeing}}
• {{cite news |url= http://www.themanufacturer.com/articles/boeing-breaks-ground-new-777x-composites-centre-st-louis/ |title= Boeing breaks ground for new manufacturing plant in St. Louis |work= The Manufacturer |date= December 13, 2014}}
• {{cite news |url=http://www.seattletimes.com/business/boeing-aerospace/boeing-revs-up-robots-for-777x-in-everett-factory-signals-that-a-797-awaits/ |title=Boeing revs up robots for 777X in Everett factory, signals that a 797 awaits |date=June 8, 2017 |author=Gates |first=Dominic |work=The Seattle Times}}

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