Boeing New Midsize Airplane

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The New Midsize Airplane would be sized between the 757 and 767 in the middle of the market.

The New Midsize Airplane (NMA), or New Midsize Aircraft,[1] is a concept airliner designed by Boeing to fill the middle of the market segment.

In 2015, Boeing determined the market was large enough to launch a new design. In 2017, multiple airlines expressed interest in a composite, seven-abreast twin-aisle with an elliptical cross-section; the new aircraft, likely to be named the Boeing 797, would be available in two versions: a 225-seater with 5,000 nmi (9,300 km) range and a 275-seater with a range of 4,500 nmi (8,300 km). Third-party forecasts for this market vary from 2,000 to 4,000 aircraft, though Boeing expects the market demand to lie at the upper end of this range. At a projected price of $65–75 million, the NMA should generate 30% more revenue than narrowbodies and have 40% lower trip costs than the widebodies it would replace, but would cost $12–15 billion to develop, it would be powered by a new 50,000 lbf (220 kN) turbofan from GE Aviation/CFM International or Pratt & Whitney, with a bypass ratio of 10:1 or more and an overall pressure ratio exceeding 50:1.

Boeing says it will decide in 2019 whether to offer the airplane to the market and in 2020 make its final decision on whether to launch the new airplane. Development would begin soon thereafter, with entry into service targeted for 2025.



Air Lease Corp.'s Steven F. Udvar-Házy believed that Boeing was planning to launch a more capable, all-new replacement for the Boeing 757 rather than a re-engined version.[2] At the International Society of Transport Aircraft Trading conference, he predicted it would be a Boeing 767-like, twin-aisle airplane capable of using 7,000-foot (2,130 m) runways such as those at New York LaGuardia. Boeing's VP of Marketing Randy Tinseth said the company was focused on developing an aircraft with 20% more range and more capacity than the 757-200.[3] United Airlines consulted Airbus and Boeing about replacing its 757s and was waiting for Boeing's response, as Tinseth wanted to fill the gap between the 737 MAX and the 787.[4]

Before the 2015 Paris Air Show, sales chief John Wojick said Boeing had held discussions with customers and determined that the market was large enough to launch an all-new jet airliner, the first since the launch of the 787 Dreamliner in 2003.[5] At the show, Airbus CEO Fabrice Bregier estimated that Boeing would have to invest $10 billion to develop a 757 successor with 220 seats and a range of 4,500 nmi (8,300 km), corresponding to the capabilities stated by Boeing's vice president for product development Mike Sinnett.[6] Vinay Bhaskara of Airways News said Boeing's middle of the market (MOM) airliner would likely launch before 2020 and enter service in the early part of the following decade.[7]

Boeing denied that the new aircraft would be an update to the Boeing 767,[8] although a revised 767 could be a possible stopgap measure.[9] Estimates suggested that the cost of developing and building a new aircraft could even reach US$15 billion.[10]


In early 2016, Boeing's two major options remained a larger 737 MAX variant or an all-new 797 design;[11] the MOM was the subject of a session of the 2016 International Society of Transport Aircraft Trading (ISTAT) conference in Phoenix, Arizona where major worldwide sellers, buyers and financiers of commercial aircraft meet.[11] Airbus sales chief John Leahy said the industry has no need for a new midmarket airplane, since the A321neo is already for sale.[11]

In July 2016, Boeing forecast demand for 4,000 to 5,000 midmarket aircraft, leaving a market for 2,000 to 3,000 after accounting for the Airbus A321neo and A330neo sales,[12] it identified the market "sweet spot" for the NMA as being a 200 to 250-seat twin-aisle aircraft with more than 4,000 nmi (7,400 km) range, but cheaper to operate than existing small twin aisles. The notional aircraft, which would enter service in the middle of the next decade, would need advanced 40,000–45,000 lbf (180–200 kN) high-bypass turbofans with higher pressure ratios. Boeing development resources were committed on the 777X, 787-10 and 737MAX, whereas Airbus's R&D spending profile appeared to leave room for new development; however, Airbus believed that the A321LR and A330neo were sufficient to address the segment.[13]


At the March 2017 ISTAT Americas conference, United Airlines' interest in the NMA was confirmed by chief financial officer Andrew Levy, who corroborated the assumption that it will be a twin-aisle aircraft[14] with two variants, carrying 225 to 260 passengers with a range of 4,800 to 5,200 nmi (8,900 to 9,600 km).[15] Multiple airlines expressed potential interest: Alaska Airlines,[16] Emirates,[1] and Delta Air Lines for transatlantic flights.[16]

The new airplane is expected to have seven-abreast seating, like the 767;[17] the market favors single-aisle economics, and Boeing's challenge is to achieve comparable hourly cost and price per seat while keeping twin-aisle capabilities.[18] Competition to supply the engines would be intense, with Rolls Royce likely to propose the UltraFan follow-on to its Advance engines, Pratt & Whitney offering a new iteration of its Pratt & Whitney Geared Turbofan, and CFM International also in the running.[19]

To assess where the "middle of the market" lies, Flight Ascend Consultancy looked at existing twin-aisle aircraft with fewer than 260 seats and found that these offer an average of 234 seats and have an average flight distance of 2,670 nmi, with 60% of available seat miles below 4,000 nmi and 82% below 5,000 nmi.[12] To be competitive, NMA pricing would have to be between the 787-8 and A330neo at $100–120 million (base full-life value) and larger single-aisles at above $50 million; the 767-300ER in its heyday cost just over $70 million.[12] An elliptical cross-section could combine a twin-aisle cabin with the reduced cargo space of a single-aisle jet to reduce aerodynamic drag and operating costs, but would need more complex carbon composites instead of a simple cylindrical metal fuselage.[20]

Boeing relies on model-based systems engineering (MBSE), already used in its defense and space businesses, to define customer needs and functionality early in the aircraft design process with an interdisciplinary approach. A systems architecture model feeds and interacts with analytic and verification models, and helps define the product to bound data management and control cost and schedule, and the constraints, interfaces and requirements. Engine integration defines takeoff and climb capability, aircraft noise and ETOPS range circumference and engine failure altitude.[21]

silhouettes of Boeing NMA concept at right between 787-8 on top and 737 MAX 10 on bottom, as presented at Paris Air Show 2017

At the June 2017 Paris Air Show, Boeing's aircraft development manager Mike Delaney confirmed the use of composites for the whole airframe, which will have a hybrid cross-section and bypass ratios above 10:1.[22] If the NMA is launched in early 2019, its design will be completed in 2020, with fabrication in 2021-22, build in 2023, flight tests and certification in 2024 and introduction in 2025.[23]

With the NMA planned for introduction no earlier than 2025, and the 787 being much larger, Boeing could conceivably restart passenger 767-300ER production to bridge the gap,[24] with potential demand for 50 to 60 aircraft.[25] In September, Boeing created a development program office, and in November named their company veteran and 777X chief project engineer Terry Beezhold, without a role yet,[26] its introduction could slip from 2024-25 to 2027, pushing the 737 replacement to after 2030.[27]

On 20 December 2017, Washington Governor Jay Inslee formed a committee with Boeing labor unions (IAM and SPEEA) and local government economic-development officials to lobby Boeing to build the NMA in Washington state.[28] Boeing continues to estimate middle-of-the-maket demand at between 2,000 and 4,000 airliners over 20 years, stating in September 2017 that it was closer to 4,000, while Pratt & Whitney, Rolls-Royce plc and Leeham Co. think it likely to lie between 2,000 and 2,500; Airbus puts the figure at about 2,000 aircraft, not enough to justify a new $15bn development program for aircraft to be sold for $55m to $75m each.[29]


2018 early design rendering

In early 2018, United saw the NMA reaching the market in eight to ten years.[30] GE Aviation expected a launch decision in 2018 in order to enter service on target in the mid-2020s.[31] Boeing was in "active" talks with about 50 potential customers and had defined two main versions: a 225-seat model with a 5,000 nmi (9,300 km) range and a 275-seat version with a 4,500 nmi (8,300 km) range.[32]

Delta Air Lines hoped to be a launch customer for the NMA, which would replace its 757 and 767 fleets.[33] Delta operates 127 757s and 80 767s with average ages from 15 to 22 years.[34] Boeing's VP Marketing Randy Tinseth is confident its forecast of 4,000 aircraft can be met, despite others seeing the market as between 2,000 and 2,500, because the NMA can change airline networks in the same way that the 787 has enabled 170 new routes to be opened since 2011.[35] Solid production costs and sales forecasts are required to convince the Boeing board to commit to its development.[36] Avolon sees a market for 3,500 to 4,000 airliners.[37]

The NMA is targeted to achieve a 30% economic improvement over the Boeing 757/767.[38] Tinseth said the NMA will generate 30% more revenue than narrowbodies and have 40% lower trip costs compared to the widebodies it would replace (767, A300 and A330).[39] Within its range, it would be significantly more economical than the A330neo, severely testing its sales if Boeing can keep NMA prices in the $70m range;[40] the target sale price for the NMA is believed to be between $65m and $75m.[41] Ryanair CEO Michael O'Leary, kept informed by Boeing, said its seat cost is substantially higher than the 737 MAX.[42]

The conceptual design released in early 2018 has a 737 MAX-style tail cone, large 787/777X-sized cabin windows, a 757/767/777-style windscreen, a 767-200 door arrangement and short engine inlets;[43] as the A320/A330 investment has been amortised, the A321LR or A330neo can be offered at a lower cost; the NMA has to offer notably lower fuel and maintenance cost. Airbus could react with an A321 stretch or an all-new design, and could use a new 50,000 lbf (222.5kN) engine.[44]

As recent all-new designs took between 88 and 101 months (7.3 to 8.4 years) between the authority to offer and the introduction, a late 2018 to early 2019 launch would imply a 2026 service entry. At this time, existing airliners over 30 years old will have been replaced by current models, leaving 900 aircraft aged from 15 to 25 years to be replaced: 420 A321s, 270 A330-200s, 90 757s and 130 767s; the largest operator of these 15-to-25 year-old mid-market types is American Airlines with over 80, followed by China Southern then Delta Air Lines, United Airlines, Air China and Turkish Airlines with less than 40.[45] In June the NMA-6X was defined as a 228-passenger, 5,000 nmi (9,300 km) airliner and the NMA-7X would seat 267 in two classes over 4,200 nmi (7,800 km).[46]

ICF International sees a market of 3,000-3,500 over 20 years with the NMA sold for $75-80 million, while Collateral Verifications believe in a 1,000-1,500 market and a $80-90 million price; for Flightglobal's Ascend, 1,500 NMAs could be delivered for $67-82 million each between 2025 and 2040 if its size is right, and Oriel Consult expects a $70-80 million price.[47] For Steven F. Udvar-Házy, a decision should be made by mid 2019, with two potential engines derived from existing units. Boeing continued to assess the market as 4,000-5,000 aircraft and was working towards a 2019 decision too, while taking measures to protect a 2025 introduction into service.[48]

The Aurora D8 concept has a double bubble fuselage

For the French national aerospace research center, ONERA, a cylindrical seven or eight-abreast twin-aisle has 20% more fuselage drag in cruise than a six-abreast, single-aisle airplane of the same seat capacity; this is significant because fuselage drag is one-third of total drag. However, an elliptical widebody can have an equivalent drag due to a smaller wetted area. Also, a twin-aisle is more comfortable and has faster turnarounds than a single-aisle. A cylindrical section is the simplest way to cope with the cabin pressurization's hoop stress while an elliptical section is reinforced and heavier (less so with vertical rods like the Aurora D8 concept).[49]

In October 2018, analysts from Sanford C. Bernstein, Morgan Stanley and Canaccord Genuity were convinced Boeing will launch the project.[50] Boeing's Randy Tinseth stated an almost unanimous preference for better economics through weight savings rather than the heavier structure to carry widebody containers.[51]


By early 2019, Rolls-Royce was anticipating an addressable market for 4,000 to 5,000 middle-of-the-market aircraft over 20 years, agreeing with Boeing's figures, and pointed out that Boeing will not capture all of that market; it expects demand for the NMA to reach 2,000 to 3,000 aircraft.[52] Former Airbus sales executive John Leahy suggested that Boeing should create a new single-aisle aircraft to compete with the Airbus A321neo from 2030 instead of a small widebody.[53]

On January 30, 2019, Boeing CEO Dennis Muilenburg clarified that whether to offer the NMA for sale would be decided later in the year, before an authority to launch decision deferred until 2020, aligned with the end of 777X development and enabling the NMA to build on 777X work;[54] the two-stage decision process is standard at Boeing and entry into service is still targeted for 2025, but the delay could cause 757 replacement opportunities to be missed.[55] Boeing intends to leverage existing technologies such as composites for the NMA; the program would overhaul supply chain practices and focus on more efficient production, support and maintenance that could also be applied to a future 737 replacement.[56]

In February 2019, Rolls-Royce plc abandoned its engine proposal, leaving CFM International and Pratt & Whitney as sole competitors.[57] A new development would not be mature enough as the Ultrafan program is too far away from Boeing's needs, but Rolls-Royce could be interested in a partnership with another manufacturer.[58]

In June 2019, following the launch of the Airbus A321XLR, Boeing was understood to be prioritizing the 275-seat variant, tentatively dubbed NMA-7X, ahead of the 225-seat NMA-6X which would compete more directly with the A321XLR. A formal authority to offer decision is still expected later in 2019;[59] the two prospective engine suppliers are understood to be bidding on a sole-supplier basis, believing that market demand would not allow two competing engines to achieve a timely return on investment, whereas Air Lease Corporation's Steven Udvar-Házy feels that buyers should have a choice. Udvar-Házy also suggested that the NMA should be designed with future changes in mind, such as the possibility of single-pilot operation.[60]


The engine selection process is reminiscent of the competition to power the 777-200LR/300ER at the end of the 1990s, which shaped the turbofan market for the subsequent years. Rolls-Royce proposed the Trent 8104 growth demonstrator, Pratt & Whitney proposed a scaled-up PW6000 (wanting to limit the competition to two suppliers), while GE won exclusivity with the GE90-115B performance and GECAS 777 orders. Rolls Royce obtained the same exclusivity for the A350, pushing P&W out of the widebody engine market and precipitating its narrowbody comeback with the PW1000G.[61]

The 45,000 lbf (200 kN) thrust was typical of the 1960s' first generation of high-bypass-ratio turbofans: the GE CF6 for the Douglas DC-10, the Rolls RB211 for the Lockheed Tristar, and the Pratt & Whitney JT9D for the Boeing 747; this market was quickly left behind as aircraft and their power requirements grew, leaving the RB211 for the Boeing 757 (until 2005), or the Pratt PW2000 for the Boeing C-17. Newer technology enabled 10:1 or more bypass ratios and overall pressure ratios of at least 50:1 at top of climb; this level of thrust is above modern CFM LEAP or Pratt PW1000G single-aisle engines, but well below Rolls-Royce Trent or GEnx widebody engines.[61]

It falls below the 50,000 lbf (220 kN) limit for CFM International, and thus a scaled-down GE9X core could fit a new low-pressure system. Pratt could reach it by growing from the 33,000 lbf (150 kN) PW1133G for the A321neo. Rolls could propose its UltraFan development, a geared turbofan based its new Advance core, but it is primarily focused on its larger, 100,000 lbf (440 kN) engine; the GTF cost more than $10 billion to develop, and Rolls is facing financial difficulties which could be accelerated by being left out of the EU Clean Sky initiative as a result of Brexit. Both could join together, but have historically been moving in the opposite direction, as Rolls sold its 32.5% stake in International Aero Engines to Pratt parent United Technologies in 2011, essentially selling the ghost of the geared IAE SuperFan proposed for the A340 (supplanted in 1987 by the CFM56).[61]

CFM International has also considered geared turbofan architecture for the prospective aircraft.[62] GE has expressed that it does not believe the market is large enough for all three suppliers and will not enter a three-way race which would not justify the investment needed–as was the case for the A330's engines–leaving Boeing's NMA with two suppliers at most.[63]

Boeing has not yet decided whether it will use a single engine type: CFM considers an all-new direct-drive engine, and Rolls-Royce proposes its Advance direct-drive engine before 2025 and its UltraFan geared design after, scalable from 25,000 to 110,000 lbf (110 to 490 kN);[64] as a new engine development costs US$2.5 to $3 billion, GE has to evaluate its market opportunities, preferring a single-source for a low-volume airplane while Airbus would potentially need such an engine.[65] GE Aviation's offer would be through CFM, with the LEAP as the baseline for a bigger engine, half a generation further, with advanced but mature enough technology.[66]

Boeing issued a request for proposals (RFP) with a June 27, 2018 deadline for a 45,000 lbf (200 kN) engine with a thrust specific fuel consumption (TSFC) 25% lower than the 757's engines.[46] At least two engine-makers want exclusivity for the $2 billion program cost. Even if its thrust crept to 52,000 lbf (230 kN), GE and Safran will bid through their CFM joint venture with a 3D-woven-resin transfer molding fan like the Leap instead of a GEnx/GE9X-type carbon-fiber composite.[67]

See also[edit]


  1. ^ a b Jens Flottau (March 9, 2017). "Emirates Considers Boeing's Midsize Aircraft 'A Winner'". Aviation Daily. Aviation Week.
  2. ^ Laura Mueller (February 27, 2015). "ALC sees 757 being replaced rather than re-engined". Flight Global.
  3. ^ Stephen Trimble (March 11, 2015). "Udvar-Hazy reveals preferences for Boeing's next project". Flight Global.
  4. ^ Gregory Polek (March 11, 2015). "United Studying Replacements for Its Transatlantic 757s". Aviation International News.
  5. ^ Dominic Gates (June 14, 2015). "Boeing looking closely at an all-new jet for 2025". The Seattle Times.
  6. ^ "Paris Air Show Buzzes Over Boeing Jet That Doesn't Exist Yet". Bloomberg. June 17, 2015.
  7. ^ "Boeing's mystery plane is the big story coming out of the Paris Air Show". Business Insider. June 18, 2015.
  8. ^ "Boeing sees "healthy" future for 767". Leeham News. August 19, 2015.
  9. ^ Bjorn Fehrm (August 27, 2015). "Boeing's 767 revitalized as a MOM stop gap?". Leeham News.
  10. ^ "The search for Boeing's MOM". Aspire Aviation. September 24, 2015.
  11. ^ a b c Dominic Gates (March 2, 2016). "Boeing wrestles with options for new midsize jet". The Seattle Times.
  12. ^ a b c Chris Seymour (Spring 2017). "Where is the middle of the market?". V1ewpoint (55). Flight Ascend Consultancy. pp. 12–15.
  13. ^ Guy Norris and Jens Flottau (February 20, 2017). "Boeing Considers Next Midmarket Moves As Airbus Watches". Aviation Week & Space Technology.
  14. ^ "United 'very interested' in Boeing MoM concept". Flightglobal. March 7, 2017.
  15. ^ Edward Russell (March 9, 2017). "Airline support gathers around Boeing MoM concept". Flight Global.
  16. ^ a b Dominic Gates (March 8, 2017). "Boeing's talking with airlines about a '797,' and they like what they hear". The Seattle Times.
  17. ^ Jens Flottau (March 17, 2017). "New Midsize Airplane Will Define Boeing's Technology Roadmap". Aviation Week & Space Technology.
  18. ^ Richard Aboulafia (March 28, 2017). "Opinion: Boeing's Twin-Aisle Midsize Jet Faces Big Challenges". Aviation Week & Space Technology.
  19. ^ Guy Norris (April 3, 2017). "Rolls-Royce Might Pitch UltraFan For Boeing New Midsize Airplane". Aviation Week & Space Technology.
  20. ^ Tim Hepher (June 7, 2017). "Boeing studies 'mild to wild' design for pivotal mid-market jet". Reuters.
  21. ^ Guy Norris (June 12, 2017). "Boeing To Unveil First New Midsize Airplane Details In Paris". Aviation Week & Space Technology.
  22. ^ Stephen Trimble (June 20, 2017). "Boeing partially unveils New Midsize Airplane concept". Flightglobal.
  23. ^ Guy Norris (June 20, 2017). "Boeing Outlines Notional NMA Timetable". Aviation Week Network.
  24. ^ "Boeing's tactical option for MOM sector". Leeham. August 14, 2017.
  25. ^ "Boeing ponders restart of 767-300ER passenger line". Leeham. October 19, 2017.
  26. ^ Jon Ostrower (November 20, 2017). "Boeing's '797' takes a big step toward becoming reality". CNN.
  27. ^ "Boeing moves EIS target for NMA to 2027: sources". Leeham. December 4, 2017.
  28. ^ Dominic Gates (December 20, 2017). "Government, labor, industry groups join to lobby Boeing on building next plane in Washington state". Seattle Times.
  29. ^ "NMA market sector is small, Airbus' Leahy says". Leeham. January 3, 2018.
  30. ^ "United sees potential new Boeing jet available in 8-10 years". Reuters. January 23, 2018.
  31. ^ Max Kingsley-Jones (February 6, 2018). "GE expects Boeing NMA decision this year". Flightglobal.
  32. ^ Michael Bruno (February 7, 2018). "Boeing: Still 'A Lot' To Be Decided On NMA". Aviation Week Network.
  33. ^ Michael Sasso (February 13, 2018). "Delta's Boss Wants to Be a Launch Customer on Boeing's '797' Jet". Bloomberg.
  34. ^ Edward Russell (February 13, 2018). "Delta interested in Boeing NMA to replace 757 and 767s". Flightglobal.
  35. ^ "NMA demand skeptics aren't thinking outside the box, Boeing exec says". Leeham. February 13, 2018.
  36. ^ Max Kingsley-Jones (February 16, 2018). "NMA decision time looms for Boeing". Flightglobal.
  37. ^ Johnson, Julie (March 6, 2018). "Boeing Faces Airline Tug of War Over Proposed '797' Jet Design". Bloomberg.
  38. ^ Hamilton, Scott (February 12, 2018). "Pontifications: NMA, Boeing-Embraer headline Singapore Air Show". Leeham.
  39. ^ "Engine makers "inside the tent" on Boeing NMA, but airframer still ponders provider". Leeham. March 5, 2018.
  40. ^ "Retirement wave coming that will boost A330neo sales, says Airbus". Leeham. March 6, 2018.
  41. ^ "Production transformation key to Boeing NMA". Leeham. March 20, 2018.
  42. ^ "Ryanair CEO: Boeing 797 niet efficiënt genoeg". Luchtvaartnieuws (in Dutch). March 6, 2018.
  43. ^ Jon Ostrower (March 12, 2018). "This is Boeing's NMA".
  44. ^ Kingsley-Jones, Max (March 20, 2018). "How Boeing's NMA could shake up the market". Flightglobal.
  45. ^ Evans, Richard (May 16, 2018). "Boeing NMA – when, and who will order?". Flight global.
  46. ^ a b Jon Ostrower (June 26, 2018). "Engine trio has due date for Boeing NMA proposals". The Air Current.
  47. ^ Airfinance Journal (September 11, 2018). "Disagreements on NMA market footprint". Leeham News.
  48. ^ Airfinance Journal (September 13, 2018). "Hazy expects 797 decision middle next year". Leeham News.
  49. ^ Thierry Dubois, Guy Norris and Victoria Moores (September 19, 2018). "Boeing NMA Engine And Fuselage-Shape Selections Loom". Aviation Week & Space Technology.CS1 maint: Uses authors parameter (link)
  50. ^ Michael Bruno (October 17, 2018). "Boeing's New Midsize Airplane Will Happen, Say Analysts". Aviation Week & Space Technology.
  51. ^ Greg Waldron (October 26, 2018). "Boeing quietly plugs away at NMA pending 2019 decision". Flightglobal.
  52. ^ "Rolls-Royces sees NMA "addressable" market as 4,000-5,000, same as Boeing". Leeham News. January 22, 2019.
  53. ^ "Forget the NMA, go after A321–say ex-Airbus exec". Leeham News. January 29, 2019.
  54. ^ Hemmerdinger, Jon (January 30, 2019). "Boeing CEO: No NMA firm launch decision this year". Flightglobal.
  55. ^ Hemmerdinger, Jon (February 1, 2019). "Boeing buys time with 2020 NMA launch timeline". Flightglobal.
  56. ^ Hemmerdinger, Jon (February 18, 2019). "How the NMA might prepare Boeing for a 737 replacement". FlightGlobal.
  57. ^ David Kaminski-Morrow (February 28, 2019). "Rolls-Royce pulls out of Boeing NMA engine contest". FlightGlobal.
  58. ^ Michael Gubisch (February 28, 2019). "Rolls-Royce 'open' to potential partnership on NMA engine: chief". Flightglobal.
  59. ^ "Boeing Pivots Towards Prioritizing Larger NMA Version First".
  60. ^ Hemmerdinger, Jon (June 18, 2019). "Udvar-Hazy foresees single-pilot evolution for NMA".
  61. ^ a b c Guy Norris (June 2, 2017). "Boeing's NMA Poses Propulsion Puzzle For Engine Makers". Aviation Week & Space Technology.
  62. ^ Guy Norris (June 21, 2017). "CFM hints at possible geared fan engine for middle of market aircraft". Aviation Week Network.
  63. ^ Christopher Jasper, Benjamin D Katz and Julie Johnsson (June 19, 2017). "GE Tells Boeing It Won't Join Three-Way Race on 797 Plane Engine". Bloomberg.
  64. ^ Max Kingsley-Jones (February 7, 2018). "Boeing studying three 'different' NMA engine designs". Flightglobal.
  65. ^ Max Kingsley-Jones (February 8, 2018). "GE outlines thinking around NMA engine business case". Flightglobal.
  66. ^ "GE/CFM in "lockstep" with Boeing on NMA". Leeham News. March 22, 2018.
  67. ^ Jens Flottau and Guy Norris (July 20, 2018). "Airbus Moves Ahead With A321XLR Definition". Aviation Week & Space Technology.CS1 maint: Uses authors parameter (link)

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