There should be little doubt that China’s aerospace ambition is to compete globally with leading aircraft makers such as Boeing and Airbus, and then to compete in the technically rigorous commercial large high bypass turbofan (HBT) market.
While gaps in data abound due to China’s pervasive secrecy, it is increasingly clear that China’s ambitions are being matched by broad investment in both commercial airframe and engine technologies. At the same time, it is pursuing, with unknown success, potentially radical rationalisation of its engine sector to spur innovation and competitiveness.
As China nears completion of its first narrowbody, the 150 seat-class Comac C919, perhaps by September this year, it has already started development of its 300 seat-class widebody, called C929. If Russia’s President Vladimir Putin gets his way, the latter could become part of a joint China-Russia widebody airliner around 2025, followed by a co-developed engine.
China’s development of modern commercial turbofans will lag behind that of its new commercial airliners, but perhaps not by much. The Comac C919 may start flying with the CFM International Leap-1C in 2016, but could have the AVIC Commercial Aircraft Engine Corporation (ACAE) CJ-1000A by 2022. The C929 will also begin with a Western engine, but could receive the CJ-2000 by 2030.
C919 - may eventually fly with home-grown engine
Comac
One reason for this lag is that since the mid-1980s, China’s top priority has been to develop modern turbofans for combat aircraft. China’s development of modern HBTs has been derivative of this effort, though by early in the last decade they appear to have gained a steadily higher policy priority. This, in turn, was spurred by the late 1990s decision to proceed with the development of heavy cargo transport aircraft and then competitive commercial airliners.
In recent years, as China’s leadership under Communist Party Secretary General Xi Jinping has embraced the policy mantra of the “China Dream”, which includes eventual global superpower status, it has also understood that its aerospace ambitions are hobbled by the lack of what they refer to as the “Chinese Heart”, or modern aircraft engines.
China’s current dependence on Western engines is near total. In an April 2015 press release on its 30 years of business in China, CFM International noted that China had ordered 3,900 CFM56 and Leap turbofans to power 1,950 Boeing and Airbus narrowbody airliners. China’s widebody airliner fleet relies almost entirely on General Electric, Pratt & Whitney, Engine Alliance and Rolls-Royce.
As of June 2015, Comac has over 500 C919 orders, mainly from Chinese customers. Initially these will be powered by CFM’s Leap-1C, but they are slated to use a Chinese engine by the mid-2020s.
China not only wants to break the foreign monopoly over its own engine market; it also hints it has set its sights on eventual foreign sales.
At the May 2015 China Aerospace Propulsion Technology Summit, it was reported that China may require 10,000 turbofan engines over the next 20 years, worth $98 billion. At the previous summit in 2014, ACAE offered its own global engine market projections. Over the next 20 years, ACAE projected a world requirement for 20,555 engines for widebody airliners, 45,777 for narrowbodies and 7,840 for regional airliners.
China’s quest for modern HBTs can be divided into three phases. First, China used its established collection of state-controlled aviation companies plus attendant research institutes under the aegis of the Aviation Industries Corporation of China (AVIC), whose predecessor organisations date to 1951. Until recently, turbofan design and manufacturing concerns have typically been subordinate to aircraft makers.
As such, the AVIC Shenyang-Liming Aero-Engine Group produced engines designed by the AVIC Shenyang Engine Design and Research Institute for aircraft from the Shenyang Aircraft Corporation (SAC). The AVIC Xi’an Aero Engine Group made engines for the Xi’an Aircraft Corporation (XAC). The AVIC Chengdu Engine Group made engines designed by the AVIC Chengdu Gas Turbine Research Institute for the Chengdu Aircraft Corporation (CAC).
While such redundancy suited the guerrilla war priorities of the Mao Zedong era, it has prevented the development of modern integrated companies capable of design, production and technology development.
Nevertheless, this model has yielded some new turbofans. Perhaps the most impressive performer from the distributed model has been the Shenyang-Liming Aero-Engine Group. In the late 1960s it developed prototypes of a high bypass derivative of the WS-6 fighter turbofan for a new transport aircraft, both of which were cancelled by Mao.
From the mid-1980s and commencement of Shenyang-Liming’s WS-10A Taihang fighter engine programme (WS is short for woshan – literally, “turbofan”), there has been an associated effort to develop HBT and marine turbine derivatives. Shenyang-Liming was heavily influenced by General Electric’s use of a common engine core for a family of engines, exploiting the core of some of the first CFM56 turbofans China obtained in the mid-1980s to help design the core of the Taihang.
Today, Shenyang-Liming’s 24,000-26,000lb-thrust (107-116kN) “WS-20” – perhaps more recently designated WS-118 – is the only indigenous Chinese HBT flying today. It has been seen on a Russian Ilyushin Il-76 engine testbed aircraft since early 2013. Galleon Consulting of Shanghai reported it would start production in 2015, but this has probably been delayed. The WS-20 is expected to succeed the 24,000lb-thrust Soloviev D-30KP-2 turbofans currently used by the XAC Y-20 heavy military transport. Chinese reports indicate there may be a 32,000lb-thrust WS-20 in development.
When it was revealed at a Shanghai exhibition in November 2009, multiple Chinese reports noted that the 26,000lb-thrust “SF-A” was the civilian/commercial version of the WS-20.
The few images available of the SF-A and the WS-20 show that the main high bypass fan on each have relatively narrow chord blades. The blades are also connected with mid-span supporting “snubbers”. These were used by early Western HBTs from the 1960s to compensate for weakness in these larger blades.
In May 2013, Galleon Consulting reported SF-A could begin production in 2016 but other reports from late 2013 note that testing was under way and production might not start until 2017 or 2018. These reports also note that by 2008, SF-A was judged to have insufficient performance for future Chinese airliners. But, pending future development, they might still be used.
WS-20 on Ilyushin Il-76 testbed
Rick Fisher
BUSINESS JETS?
Galleon also reported that by 2015, Shenyang-Liming would be producing the 2,000lb-thrust Jiuzhai twin-spool turbofan, intended for light business jets. However, this cannot be confirmed. Jiuzhai is usually associated with the Cirrus SF50 Vision light passenger jet. China Aviation Industry General Aviation, a division of AVIC, purchased Cirrus in 2011.
According to Galleon, the AVIC Guizhou-Liyang Aero-Engine Group was to start producing the 16,000lb medium thrust WS-12C HBT in 2015, but this cannot be confirmed either. It is intended to power the Comac ARJ-21 regional airliner, which currently uses the 15,400lb-thrust General Electric CF34-10A turbofan. The WS-12C is likely derived from the 6,400lb-thrust Minjiang turbofan, revealed as a product of the Chengdu Aero-Engine Group at the 2008 Zhuhai air show.
The Guizhou and Chengdu air and engine concerns appear to be developing deeper co-operation. Perhaps in the late 1990s, the Chengdu Aero-Engine Group began a programme to co-produce or copy the D-30KP-2, known as the 24,000lb-thrust WS-18A. Galleon reports the WS-18A that reportedly powers Xi’an’s Y-20 larger transport and H-6K medium bomber started production in 2009. It could enter “commercial” service if the Y-20 were to be purchased by a commercial airline.
PHASE TWO
It appears that after 2005, political dissatisfaction with the ability to develop and produce modern commercial turbofans led to a second stage in China HBT development: reform within AVIC to spur better results.
In January 2009 it was decided that AVIC would increase institutional focus on commercial engines by the creation of its ACAE unit as an “integrated” engine concern. ACAE literature states it is “responsible for the design, R&D, assembly, test, sales and service, technology development and technology consulting of commercial aircraft engines in China”.
ACAE has established its new design, R&D, technology development and consulting facilities in the Minhang-Shanghai area. A new large production and test centre is being built in the Shanghai-Pudong-Lingang area.
However, the high-profile revelation of a half-scale mock-up of the ACAE’s CJ-1000A turbofan in June 2011, about 2.5 years after ACAE’s founding, at least suggests that ACAE may have relied on established companies like Shenyang and Xi’an for early design work. It may also have adopted the reportedly more advanced SF-B.
ACAE’s website indicates that it regularly seeks advice from other established engine design, production and development organisations; indeed, it lists nine organisations that contributed to an April 2015 ACAE organised seminar on project configuration management for its CJ-1000AX demonstration turbofan.
From 2012 to 2014, limited information about the CJ-1000 turbofan family has been revealed. In 2012, Lucintel Consulting of Irving, Texas revealed the CJ-1000 would include three initial versions: the CJ-1000AX demonstrator that would produce 12.8t take-off thrust; the CJ-1000A early production model that would produce up to 14t of thrust; and the CJ-1000B, an extended range version that would produce 13.4t of thrust.
At the May 2014 propulsion summit, ACAE senior expert for design and R&D Ni Jingang, who worked with Safran China from 1997 to 2010, provided projected milestones for the CJ-1000 family. The CJ-1000AX demonstrator would be finished by 2018, two years later than previously reported. By 2022 the CJ-1000A would equip the C919 and the CJ-1000B would follow by 2026. He expected airworthiness certification to occur between 2022 and 2026.
Given the delay encountered by the CJ-1000AX demonstrator, the projections for production and certification may also prove optimistic.
While it did not refer to the CJ-1000, an ACAE brochure on its engine programme from the 2012 Zhuhai air show lists the potential technology improvements the CJ-1000 may exhibit. These may include: use of wide-chord, curved, swept hollow main fan blades; single crystal-powdered metal blades with “advanced cooling technology” for the high-pressure turbine; curved-swept blades for the high pressure compressor; compact single annular combustors; plus full authority digital engine control (FADEC) and “advanced engine fault diagnostics”.
Reports from 2011 indicated that a future version of the CJ-1000 could have a thrust of 44,000lb, but at the 2014 Galleon Summit, Ni Jingang also revealed that a new “CJ-2000” was being developed for a future widebody airliner. He did not reveal its projected thrust, but given that the widebody airliner is in the 250-300 seat class, a 50,000-60,000lb estimate is plausible. Ni did, however, say that CJ-2000 technology studies should be complete by 2020, a test engine complete by 2022 and certification complete between 2025 and 2030.
During a press conference at the June 2015 Paris air show, a representative from Russia’s United Aircraft Corporation indicated that a joint China-Russia engine development programme was possible for the proposed joint China-Russia widebody airliner. Other Russian sources at the show indicated that the 28,000lb-thrust Aviadvigatel PD-14 could serve as the basis for a more powerful turbofan.
At the 2014 summit, Ni also referred to a “CJ-500” intended for smaller regional jets, but did not provide additional details.
PHASE THREE
A third phase in China’s development of advanced turbofans could emerge from the 2014 decision to form an entirely new engine organisation from AVIC’s distributed companies and institutes. Early indications that such a decision had been made included September 2014 job recruitment postings for a new company called “AVIC Engine Holdings Ltd”, also dubbed the “AVIC Engine Company”.
According to Chinese reports, AVIC Engine will gather 25 to 27 engine-related units and 80,000-85,000 personnel. An AVIC website describes it as “engaged mainly in military and civilian aircraft engines, helicopter transmission, secondary power systems, gas turbines and other derivatives product development, manufacturing, marketing and services business”.
A decision to move beyond reform from within, like with ACAE, towards wholesale restructuring may reflect concern that even ACAE’s new CJ-1000 family may be continually behind Western turbofans. However, what is not known is how AVIC Engine will move to achieve new efficiencies, perhaps maintaining some internal competition or perhaps seeking much greater specialisation among subordinate companies.
But this effort to form a world-class engine sector could receive substantial funding, with Chinese reports indicating that up to CNY2 trillion ($322 billion) could be spent over the next 20 years.
Source: FlightGlobal.com
