CRAIC CR929

Discussion in 'Air Force' started by Iron Man, Jun 5, 2018.

  1. Iron Man
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    Comac CR929 Now Larger Than Airbus A330

    Bradley Perrett and Maxim Pyadushkin
    The Sino-Russian Craic CR929 widebody airliner has grown during development and now requires greater thrust than envisaged before program launch last year. The aircraft, comparable with the Airbus A330-900 in a 2015 concept design, is now rather larger: It is approximately the same length as the Airbus aircraft but has a wider fuselage, enough for nine-abreast economy seating.

    An engine type generating 78,000 lb. thrust is now needed; in 2015, thrust per engine was 71,226–75,000 lb.

    Craic is a consortium of Comac and United Aircraft Corp. (UAC). Comac has released basic data for one preliminary design iteration; UAC unit Sukhoi Commercial Aircraft has provided figures for another, evidently the latest one. Differences presumably reflect progress in refining characteristics.

    • Dimensions and thrust have crept up from the original concept design’s
    • But Comac and UAC are sticking to 12,000-km range
    Range in both available design iterations remains as it was in the 2015 concept: 12,000 km (7,460 mi.), about the same as for the A330-900 and Boeing 787-10. This is enough to cover 95% of medium- and long-haul routes, says Comac.

    In the design described by Sukhoi, seating in a three-class cabin arrangement is 281. The A330-900 has a typical three-class capacity of 287, says Airbus, but the comparison is almost meaningless, because of the great number of variations in premium cabins in long-haul aircraft.

    More telling are fuselage dimensions. These show that the CR929 will carry more passengers than the A330-900 for a given seating standard. The aircraft is now 63.25 m (208 ft.) long, says Sukhoi. That is just 45 cm (18 in.) shorter than the A330-900.

    The Russian company does not give the width of the fuselage, but for the preliminary design described by Comac the figure is about 5.9 m. This can be judged from the proportions of a drawing of that design. For the 2015 concept design the precise measurement was 5.92 m, obviously intended for nine-abreast seating. Width is unlikely to have changed much in the design for which Sukhoi provided figures.

    [​IMG]
    This approximate drawing is based on a design published by Comac, called Design Iteration A in the table. Credit: Scott Marshall/AW&ST
    The A350, designed for rows of nine seats, has almost the same width, 5.96 m. The A330, by contrast, is wide enough for only eight-abreast seating. Craic has rejected the choice Boeing made with the 787: to design a fuselage that could take rows of eight comfortably wide seats and aisles or nine narrow seats in a squeezed arrangement.

    The CR929 is evidently intended mainly to replace the A330-300, which has the same fuselage length as the A330-900, says Sash Tusa from analysis company Agency Partners in London. A330-300s have become the workhorses of China’s busiest domestic routes over the past decade; they will be ripe for replacement in the years after 2027, the latest point at which the CR929 is supposed to be ready for service.

    Comac and Sukhoi may have increased the size of the CR929 because they expect airlines to want more seats for A330-300 missions by the time aircraft of that type retire. The design may have been enlarged twice. The chief designer for the CR929 at Comac, Chen Yingchun, said in September 2017 that 75,000 lb. was required. That was at the top end of the band in the 2015 concept design; now an even higher figure is specified.

    Comac showed one preliminary design iteration on May 15 at an aeroengine conference in Shanghai organized by Galleon. Sukhoi subsequently provided details at Aviation Week’s specific request, so its figures should relate to the latest design. (In the table shown the two sets of data—from Comac and Sukhoi, respectively—are only arbitrarily labeled as Design Iterations A and B; official names for them are unknown.)



    [​IMG]
    Aviation Week published details of the concept design in late 2015 (AW&ST Oct. 12-25, 2015, p. 37). It was defined only approximately by ranges of values, but figures for fuselage dimensions, weight and thrust indicated that the aircraft’s size was in the ballpark of the A330-900’s. Fuselage length is now at the upper end of the concept-design ranges, and the increase in thrust suggests that weight has correspondingly increased.

    Span has apparently risen in at least two steps: in the design described by Comac it is in the upper half of the 58-61-m band planned in 2015; in the design detailed by Sukhoi, it is well beyond that band. Indeed, at 63.86 m it is barely less than the values for the A330-900 and A350.

    To compete, Craic first needs a Western engine for the CR929, and it requested proposals in December. GE Aviation or Rolls-Royce are the only contenders, because Pratt & Whitney is concentrating on engines for narrowbody aircraft. Chinese and Russian engine companies have proposed alternatives; a merged Sino-Russian engine program is also possible.

    In 2016 UAC assumed Rolls-Royce or GE would each offer an engine of about the same technology level as was then available for Airbus or Boeing aircraft. GE’s candidate would probably be a version of the GEnx, which in its GEnx-1B76 standard produces 76,100 lb. thrust for the 787-10. Rolls-Royce is likely to offer a version or derivative of the Trent 7000. This is rated at only 68,000–72,000 lb. for the A330-900 but is closely related to the Trent 1000 TEN of the 787, which the FAA has certified at 78,129 lb.

    A consideration for the engine-makers is that Craic is likely to want the chosen turbofan to have spare thrust for the planned stretched version of the CR929.

    —With Guy Norris in Los Angeles


    http://aviationweek.com/commercial-aviation/craic-cr929-now-larger-airbus-a330
     
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  2. supercat
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    supercat Junior Member

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    From AW&ST:


     
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  3. Skywatcher
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    Skywatcher Senior Member

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    Huh, first time I can recall in a large cutting edge aerospace project where the R&D timeframe was reduced.
     
  4. asif iqbal
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    asif iqbal Brigadier

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    I wonder who the first customer is going to be and how many orders the C929 gets in the next few years
     
  5. weig2000
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    weig2000 Junior Member

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    At least there is no lack of customers in China. Chinese airlines have been flying domestic routes using 787, 777, 747, 330. Many of them.
     
  6. Tirdent
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    Tirdent Junior Member
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    A few earlier musings that would've belonged in here had the thread existed at the time:

    https://www.sinodefenceforum.com/chinese-aviation-industry.t4234/page-197#post-510420

    What caught my attention about the new AvWeek article is the assertion that the fuselage will have significant metal content. Considering the recent composite fuselage panel demonstrators and the claimed >50% composite content (roughly on a par with the A350 and 787), that seems like an error to me.
     
    #6 Tirdent, Jun 14, 2018
    Last edited: Jun 14, 2018
  7. Skywatcher
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    Skywatcher Senior Member

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    You need metal for a lot of the structural support and load bearing sections in the fuselage (there's a plan to build an all composite jetliner in about a decade, but it's only a 30-50 seater IIRC).
     
  8. by78
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    by78 Major

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    CR929-600, general layout design completed. Below are high-resolution photos of a small ceremony marking the occasion.

    [​IMG]
    [​IMG]
     
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  9. Iron Man
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    Craic Cuts CR929 Schedule By Two Years

    Bradley Perrett
    Boeing took more than seven years to develop the 787; Airbus needed eight for the A350. So Chinese and Russian partners, with less experience than the Westerners, seemed suitably conservative a year ago when they launched the Craic CR929 into a 10-year development program.

    They are no longer so conservative: The schedule has been compressed by 20%, with the initial delivery now due in 2025 following a first flight in 2023.

    The CR929 will feature extensive use of electrically driven systems and a cockpit with commonality with Comac’s C919, says a Comac official, listing other technologies and updating the schedule. Composites will exceed 50% of the structure.
    • First delivery is now due in 2025
    • Technology will include increased use of electricity
    Comac and United Aircraft Corp. (UAC) are equal partners in the Craic consortium. Published dimensions of the preliminary design show the CR929-600, the first version of the aircraft, will be larger than the Airbus A330-900 and fly about as far: 12,000 km (7,500 mi.). The partners agreed on undisclosed final dimensions and the design layout on June 6. The final dimensions are different from the figures UAC provided to Aviation Week in May, says an industry source.

    The span and shape of the wing are now settled, along with the size and form of the fin and length of the fuselage, including measurements for the nose and tail sections, says UAC. Locations of the engines, landing gear and doors also are now fixed, says UAC.

    “The plan for our program is to begin building the first aircraft in 2021, conduct the first flight in 2023 and make a delivery to the first customer in 2025,” a Comac official told the Aviation Technology Forum, a conference organized by SAE International. This timetable is two years shorter than the one stated in November 2016, when Comac and UAC were preparing for full-scale development, which eventually was launched in May 2017. Two years ago, the first flight was due seven years after program launch, meaning it would happen in 2024. But UAC President Yuri Slyusar said in 2016 that managers would try to cut development time by a year or two.
    [​IMG]
    Comac and UAC displayed this model of the CR929 in 2016. Credit: Brad Perrett/AWST
    The eight-year schedule now stated by Comac matches the one that the Chinese state company badly missed with the C919, which at the time of program launch in 2008 was supposed to fly after six years; first delivery was due two years after that. The company is now aiming to deliver the first C919 in 2021, after 13 years of development. The Comac ARJ21 took 13 years, but Russian industry produced the Sukhoi Superjet 100 in 11 years. UAC expects to deliver the first Irkut MC-21 in 2020, which will be 13 years after program launch.

    A risk to the CR929 schedule is the difficulty of multinational management. Coordination between the partners before program launch was poor, said industry sources familiar with the preliminary work.

    Since full-scale development began, disagreements over technological targets have been a theme, says one industry source. In general, the UAC program managers, building on a century of development of Soviet and Russian transport aircraft, are pushing the latest technology, that person says. The Chinese, lacking such a background, are more cautious. They presumably also assume that their government, controlling a huge aviation market, can ensure Craic receives substantial orders for the CR929 even if it lacks great technical advantage over competitors.

    Nonetheless, the Comac official at the conference described plans for what would be an up-to-date widebody airliner. These include increased use of electricity, what the industry calls more-electric technology. Traditionally, much power for equipment on airliners has been distributed hydraulically or—using air bled from the engines—pneumatically. The recent trend is to use more electricity—also sourced from the engines, but via mechanically driven generators—to save weight and improve propulsion efficiency. In the CR929, electricity will drive the environmental control system, thrust-reversing, braking and flight-control actuation, says the Comac official.

    “Usage of composites will exceed 50%,” the official says, not defining how that ratio is calculated—for example, by weight. The statement is consistent with the structural scheme described in 2016, in which UAC would build a composite mainplane while Comac would manufacture a metal fuselage that incorporates considerable composite material. Extensive use of composites in the CR929 will reduce maintenance costs, says Comac.

    Aerodynamic design will include “a new-generation supercritical wing, low aerodynamic noise and multidisciplinary optimization,” the Comac official told the conference. The aim is to achieve “a marked improvement in aerodynamic efficiency.”

    As for flight-control technology, Craic is planning three-axis, full-time, full-authority digital signaling and enhanced envelope protection. The system will be designed to alleviate loads imposed by gusts and maneuvers and allow for a lighter structure.

    Avionics hardware and software will be standardized and modular. Craic wants to reduce the volume, mass and power consumption of the avionics while increasing their maintainability. Commonality with the C919 will be maintained in the design of the cockpit and fly-by-wire system, the Comac official adds, not mentioning any such relationship with the MC-21.

    Craic says it has received seven engine proposals for the CR929. Some must have come from organizations that Craic could not realistically choose. Rolls-Royce and General Electric should have made proposals, since one of those companies probably will provide the CR929’s initial powerplant. Aero Engine Corp. of China and Russia’s United Engine Corp. can be assumed to have lodged proposals; each has offered an engine that would be a later alternative to the initial British or U.S. type. A joint Sino-Russian engine design is possible, but the two sides so far are conducting little more than market studies for one. Pratt & Whitney is not known to be working on an engine of the necessary thrust, which will be 78,000 lb., according to UAC.

    The CR929 is supposed to deliver a 10% reduction in operating costs, though the comparison aircraft is not stated. The goal appears to be focused mainly on structural lightness, since the industry these days does not expect great leaps in aerodynamic efficiency and the CR929’s engine is likely to be a derivative of one already in production.

    The composite wing should give the CR929 an advantage over the all-metal design of the A330-900, but the Boeing 787-10 has a wing, fuselage and tail largely made of carbon-fiber reinforced plastic. The CR929 fuselage could benefit from light new aluminum alloys, however.

    —With Maxim Pyadushkin in Moscow
     
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  10. vincent
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    vincent Junior Member

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    True or false?
     

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