By late 2014 China had completed a fifth prototype of its new J-20 stealth fighter and successfully flown this new prototype. About the same time China announced that it will not export the J-20. This is a major disappointment for manufacturer CAC (Chengdu Aircraft Company), which also produced the JF-17 and J-10. Export sales are more profitable than selling to the Chinese military.
The J-20 made its first flight in 2011, and many more since then. Each of the new prototypes appeared with several modifications, except for the latest one which seems identical to prototype 4, at least externally. The last two prototypes came with the new ASEA radar already installed. It is also interesting that three of the five prototypes were delivered and flew in 2014.
The J-20 is estimated to have a max weight of 36 tons. While the J-20 looks like the American F-22 when viewed head on, it's overall shape, weight, and engine power is closer to the American F-15C. In other words, it's about 20 meters (62 feet) long, with a wing span of 13.3 meters (42 feet). The J-20 has about the same wing area as the F-15C, which is about 25 percent less than the F-22 (which is a few percent larger than the F-15 in terms of length and wingspan). Worse, for the J-20, is the fact that its engine power is about the same as the F-15C, while the F-22 has 65 percent more power. With the afterburner turned on, the J-20 has more power than the F-15C and nearly as much as the F-22. But because the afterburner consumes so much fuel you can't use more than a few minutes at a time. The new J-20 model appears to be able to supercruise, joining the F-22, Eurofighter, and the Gripen as aircraft that can supercruise (go faster than the speed of sound without using the afterburner).
The J-20 has some stealthiness when it's coming at you head on. But from any other aspect, the J-20 will light up the radar screen. For this reason the J-20 first appeared to be a developmental aircraft, not the prototype of a new model headed for mass production. China now indicates that the J-20 is the basis for a new fighter and will go through as many design and shape changes are needed to become combat ready. As such, J-20 is only the fourth stealth fighter to fly, the others being the U.S. F-22 and F-35, plus the Russian T-50. The older U.S. F-117 was actually a light bomber and the B-2 was obviously a heavy bomber. Based on recent Chinese warplane development projects (J-11 in particular), the J-20 has a long development road ahead of it.
While the shape of the J-20 confers a degree of stealthiness (invisibility to radar), even more electronic invisibility comes from special materials covering the aircraft. It's not known how far along the Chinese are in creating, or stealing, these materials or the needed engines. China would most likely use the J-20 singly, or in small groups, to seek out and attack American carriers. To make this possible F-22 class engines are needed and that is still in development. Over the last few years China has admitted it has been developing the WS-15 engine (since the 1990s), a more powerful beast well suited for the J-20. No date was given as to when the WS-15 would be available for use or whether it would have the same vectoring (ability to move the hot jet exhaust in different directions in order to make the fighter more maneuverable) the F-22 uses.
For the J-20 to be a superior fighter, it would need electronics (including radars and defense systems) on a par with the F-35 and F-22. So far, the Chinese have not caught up with stuff used by current American fighters. But the gap is being closed, faster than it was during the Cold War when the Russians were creating, or stealing, their way to military tech equivalence with the West. The Russians never made it but the Chinese believe they can succeed.
Work on the J-20 began in the late 1990s, and the Chinese knew that it could be 25 years or more before they had a competitive stealth fighter-bomber. The J-20 is being tested in central China. The twin engine J-20 appears to be about the same weight class as the 30 ton F-15C. The F-35A is a 31 ton, single engine fighter, while the twin-engine F-22 is slightly larger at 38 tons. The Russian T-50 weighed in at 37 tons.
China is also developing other support technologies, like the AESA radar, highly efficient cockpit layout, stealth, and software to tie everything together. Developing, or even copying, this tech is not easy. But the Chinese already know that, having decades of experience adapting stolen technology to their needs. Thus, it appears that China is planning on having the J-20, in some form, ready for service by the end of the decade. The key factor is their ability to develop or steal the needed technology by then. The J-20 appears to be a fighter-bomber, as this kind of aircraft would be most useful dealing with the U.S. Navy and key targets in Taiwan or Japan. In any event, the J-20 is an attempt to develop some kind of 5th generation aircraft, complete with stealth.