Xian Y-20

Y-20
Y-20 flight on Airshow China 2016
Role	Strategic airlifter
National origin	People Republic of China
Manufacturer	Xi'an Aircraft Industrial Corporation
Designer	Tang Changhong[1]
First flight	26 January 2013
Introduction	6 July 2016[2][3]
Status	In service, in production[2][3]
Primary user	PLA Air Force
Produced	2013-present
Number built	8 as of Jan. 2016[4]

The Xian Y-20 (Chinese: 运-20) is a large military transport aircraft. The project is being developed by Xi'an Aircraft Industrial Corporation and was officially launched in 2006.^[5] The official codename of the aircraft is Kunpeng (Chinese: 鲲鹏).^[6] after the mythical bird of ancient China that can fly for thousands of kilometres.^[7] However, within the Chinese aviation industry itself, the aircraft is more commonly known by its nickname Chubby Girl (Chinese: 胖妞), because its wide fuselage in comparison to other Chinese aircraft previously developed in China.^[8]

Design and development

Y-20 at Airshow China 2014

The Y-20's general designer is Tang Changhong (Chinese: 唐长红),^[1] (the general designer of Xian JH-7), and the deputy general designer is Guo Zhaodian (Chinese: 郭兆电).^[8] The aircraft was primarily designed and developed in China under Xi'an Aircraft Industrial Corporation.^[9]

The Y-20 uses components made of composite materials.^[10] The composites are produced in China, whereas in the past they had to be imported.^[11] The Y-20's cabin incorporates flame-retardant composites developed by the 703 Institute of the China Aerospace Science and Technology Corporation (CASC). The 703 Institute was created in March 2009 with development taking three years. The performance of the composites is reportedly comparable to those that fulfill FAR Part 25.835. The 703 Institute achieved another milestone by establishing a comprehensive Chinese evaluation and certification system for aircraft composite materials based on international standards.^[12]

The Y-20 is the first cargo aircraft to use 3D printing technology to speed up its development and to lower its manufacturing cost.^[13] Model-based definition (MBD) is also used, and it's the third aircraft to utilize MBD technology in the world, after Boeing 787 (2005) and Airbus A380 (2007).^[14] A project team to implement MBD for Y-20 program was formally formed in October 2009, and after the initial success in application on the main landing gear, MBD application was expanded to the entire aircraft and became mandatory for all contractors and sub contractors of the Y-20 program.^[14] The implementation of MBD was initially met with strong resistance, with only a third of suppliers agreed to implement MBD, but the general designer of Y-20 declared those who refuse to do so will be banned from participating in Y-20 program, thus forcing everyone to comply, resulting in increase in productivity.^[14] The implementation of MBD greatly shortened the time required, for example, without MBD, installation of wings takes a month or two, but with MBD adopted, the time is drastically shortened to just a few hours, and in general, the design work reduced by 40%, preparation for production reduced by 75%, and manufacturing cycle reduced by 30%.^[14]

In addition to 3D printing, Y-20 is also the first aircraft in China adopting associative design technology (ADT) in its development, the second aircraft to do so in the world, after Boeing 787.^[14] Headed by the deputy general designer of structural design, Mr. Feng Jun (冯军), the initial attempt to implement ADT actually failed after two months spent on application on the nose section. It was only after the second attempt that took another three months on the application on wings did ADT became successful.^[14] The adaptation of ADT greatly shortened the development time by at least eight months, and modification of wing design that previously took a week is shortened to half a day.^[14]

Cargo is loaded through a large aft ramp that accommodates rolling stock. The Y-20 incorporates a shoulder wing, T-tail, rear cargo-loading assembly and heavy-duty retractable landing gear, consists of three rows, with a pair of wheels for each row, totaling six wheels for each side. The structural test was completed in 194 days as opposed to the 300 days originally planned, thanks to the successful development and application of an automated structural strength analysis system.^[14] In comparison, similar work for Xian JH-7 took a year.^[14] According to the deputy general designer, the shortest take-off distance of Y-20 is 600 to 700 meters.^[8] Y-20 incorporates a total of four LCD EFIS, and the development of EFIS for Y-20 utilizes virtual reality via helmet mounted display.^[8] Eight types of different relays used on Y-20 are developed by Guilin Aerospace Co., Ltd. a wholly own subsidiary of China Tri-River Aerospace Group Co., Ltd.(中国三江航天集团), which is also known as the 9th Academy of China Aerospace Science and Industry Corporation (CASIC).^[12]

It was reported that the Y-20 started ground testing from December 2012, including runway taxi tests.^{[15][16][17][18]} The aircraft made its maiden flight lasting one hour on January 26, 2013.^[19][20][21] During landing in first flight, it was reported that the Y-20 prototype bounced once before finally settling on runway due to high landing speed.^[22] In December 2013, a new Y-20 prototype took to the sky.^[23]

On 6 February 2016 the Y-20 was flown for the first time and pictures of the fifth prototype (serial number 788) in flight appeared on Chinese military webpages. Other known prototypes carry identification numbers 781, 783 and 785. On 27 January 2016, former Chinese test pilot Xu Yongling had reported in a Xinhua article that Chinese aviation industry officials had stated that the Y-20 "completed development" at the end of 2015. Xu, who participated in the Chengdu Aircraft Corporation J-10 fighter test programme, suggested that the Y-20 could enter service with the People's Liberation Army Air Force (PLAAF) in 2016.^[24]

Propulsion

The first Y-20 prototype is powered by four 12-ton thrust Soloviev D-30KP-2 engines.;^[25] early production units are likely to be similarly powered.^[26][27] The Chinese intend to replace the D-30 with the 14-ton thrust WS-20, which is required for the Y-20 to achieve its maximum cargo capacity of 66 tons.^[25] The Shenyang WS-20 is derived from the core of the Shenyang WS-10A, an indigenous Chinese turbofan engine for fighter aircraft.^[28]

In 2013, Shenyang Engine Design and Research Institute was reportedly developing the SF-A, a 28700-pound thrust engine, for the Y-20 and the Comac C919. The SF-A is derived from the core of the WS-15. Compared to the WS-20, the SF-A is a conservative design that does not seek to match the technology of more modern engines.^[29]

Future production

In 2014 the PLA National Defence University's Center for Economic Research recommended the purchase of up to 400 Y-20s, comparing the PLAAF's needs with the existing airlifter fleets of the United States and Russia.^[27] In June 2016 Jane's reported that up to 1,000 Y-20s are being requested by the Chinese military.^[30]

On 6 July 2016 the first serial Y-20 (seriall number 11051) was handed over to the PLAAF in a ceremony.^[31] The second aircraft serialled 11052 to follow soon - it is assigned to the 12th Regiment of the 4th Transport Division at Qionglai, Chengdu.^[32]

Operators

•  People's Republic of China - People's Liberation Army Air Force: At least two aircraft stationed at Qionglai Air Base since July 2016^[33]

Specifications (estimated)

General characteristics

• Crew: 3: pilot, copilot & load master
• Payload: 66 tonnes^[19] (145,505 lb)
• Length: 47 m^[34] (154.2 ft)
• Wingspan: 45 m^[35] (147 ft ~ 164 ft)
• Height: 15 m (49.2 ft)
• Wing area: 330 m² (3550 ft²)
• Empty weight: 100,000 kg (220,400 lb)
• Max. takeoff weight: 220,000 kg (485,000 lb)
• Powerplant: 4 × turbofans Soloviev D-30KP-2 (WS-20 future planned)

Performance

• Cruise speed: Mach 0.75 (918 km/h)
• Range: 4,500 km with max payload; 7,800 km with 40 tons; 10,000+ km with paratroops. ()
• Service ceiling: 13,000 m (42,700 ft)
• Max. wing loading: 710 kg/m² (145 lb/ft²)

Comparable Aircraft

• Boeing C-17 Globemaster III
• Ilyushin Il-76

References

Notes

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