The Y-20's general designer is Tang Changhong, (the general designer of Xian JH-7), and the deputy general designer is Guo Zhaodian.
The Y-20 uses components made of composite materials. The composites are produced in China, whereas in the past they had to be imported. 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.
The Y-20 is the first cargo aircraft to use 3-D printing technology to speed up its development and to lower its manufacturing cost. Model-based definition (MBD) is also used, and it's the 3rd aircraft to utilize MBD technology in the world, after Boeing 787 (2005) and Airbus A380 (2007). 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. 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. 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%.
In addition to 3-D 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. Headed by the deputy general designer of structural design, Mr. Feng Jun, 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 didADT became successful. 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.
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. In comparison, similar work for Xian JH-7 took a year. According to the deputy general designer, the shortest take-off distance of Y-20 is 600 to 700 meters. Y-20 incorporates a total of four LCD EFIS, and the development of EFIS for Y-20 utilizes virtual reality via helmet mounted display. 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., which is also known as the 9th Academy of China Aerospace Science and Industry Corporation (CASIC).
It was reported that the Y-20 started ground testing from December 2012, including runway taxi tests. The aircraft made its maiden flight lasting one hour on January 26, 2013. 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. In December 2013, a new Y-20 prototype took to the sky.
The first Y-20 prototype is powered by four 12-ton thrust Soloviev D-30KP-2 engines.; early production units are likely to be similarly powered. 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. The Shenyang WS-20 is derived from the core of the Shenyang WS-10A, an indigenous Chinese turbofan engine for fighter aircraft.
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.
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, Russia, and India. Other Chinese observers note that a large order may be inappropriate due to design limitations; the Y-20 lacks advanced features like externally blown flaps and winglets, and the cargo bay may not be wide enough. They believe that the Y-20 should only be an interim measure; 50-100 should be ordered, leaving resources to develop a more capable aircraft using the Y-20 experience.