The J-20’s stealth features has been copied from the US F-22 and the Y-20 transport is a replica of the Boeing C-17. China still has inferior jet engines.
On 6 February 2016 the Y-20 was flown for the first time and pictures of the fifth prototype 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.
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 engine.
The J-20 stealth fighter and Y-20 transport plane are undergoing relevant test flights based on schedules
The Pentagon’s latest annual report to the US Congress on China's military and security progress indicates that China is closing the military technology gap in several areas.
The J-20 and the FC-31 are fifth-generation stealth aircraft with high maneuverability, low-observability and internal weapons bays, capable of operating in a network-centric environment. They could enter service as early as 2018, although the report is undecided on whether the FC-31 is for export only. Both of them have radars with advanced tracking and targeting capabilities, and protection against electronic countermeasures.
The PLAAF “is rapidly closing the gap with western air forces across a broad spectrum of capabilities,” the report assesses. These include command-and-control, electronic warfare and datalinks. The J-10B, the latest version of the indigenous fighter that was unveiled in 2007, is expected to enter service shortly. Four J-11Bs (the Chinese-produced Su-27) have been deployed to one of the islands in the South China Sea that China has been expanding by land reclamation. An indigenous version of the Russian Kh-31P anti-radiation missile is being fielded on Chinese fighter-bombers.
The PLAAF has acquired three Ilyushin Il-78 aerial refueling aircraft from Ukraine to augment the domestically produced H-6U tanker. Flight tests of the Y-20 large airlifter continue, and it could also be produced as a tanker, as well as an AEW (airborne early warning) aircraft.