For the first time China showed off its most advanced stealth warplane, the J-20, at a Chinese air show during the first week of November. China expects the J-20 to enter service in 2018 and has apparently changed its mind about exporting the J-20. Since 2014 China has offered its 18 ton J-31 stealth fighter to export customers as the FC-31 but insisted that it would not export its more advanced J-20. What apparently changed this policy was Chinese belief that they had solved the engine problems and could build their own engines and not be dependent on Russian engines.
The J-20 made its first flight in 2011, and many more since then. There in addition to the two original J-20 prototypes six more were built between 2012 and 2015, each incorporating changes. By the end of 2015 the final design was ready for production. This J-20 is a 36 ton aircraft that looks like the American F-22 when viewed head on. Yet the J-20's overall shape, weight, and engine power is closer to the American F-15C. The J-20 is 20 meters (67 feet) long, with a wing span of 13 meters (44 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 latest J-20 model appears to be able to supercruise (go faster than the speed of sound without using the afterburner), joining the F-22, Eurofighter, and the Gripen as aircraft that can supercruise.
The J-20 has some stealthiness (invisibility to radar) 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 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 fifth 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 but the current version is seen fit for service, both with the Chinese air force and navy as well as export customers. .
While the shape of the J-20 confers a degree of stealthiness, 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. It was never clear 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. From the beginning 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.
The Americans have one major advantage. They are the only nation that has successfully developed and used stealth aircraft in combat. The F-117 (a light bomber) entered service in 1983 followed by the B-2 in 1997, the F-22 in 2005 and the F-35 in 2015. The F-117 saw combat during the 1980s and the other stealthy aircraft did so within five years of entering service.
The first flight of the F-22 took place in 1997 and it entered service in 2005. During eight years of flight tests the eight prototype F-22s made 3,500 flights. The Russian T-50 appears closer to the F-35, than the F-22 and is way behind schedule. In 2007 Russia said the T-50 would have its first flight in 2009 and be in service by 2017. That schedule keeps slipping. The six T-50 prototypes have made only 700 test flights in the last six years. The J-20 moved through development faster because the Chinese set the bar lower and seems willing to cut corners to get something useful and affordable into production. It appears that the J-20 will cost about $120 million each to produce. Even with development costs added the aircraft would cost between $150 million and $200 million. China was able to steal a lot of American and Russian aircraft technology and that kept development time, and costs, down.