The Pentagon wants a new aircraft (lets call it the F-22E Strike Raptor) must be able to operate in the "anti-access/area-denial environment that will exist in the 2030-2050 timeframe. The US airforce wants offensive and defensive "counterair" -- destroying or neutralizing an enemy's ability to control the skies. Boeing Co, the Pentagon's No. 2 supplier after Lockheed, might be able to stay in the fighter business long enough to compete for it, he said, assuming exports can keep its fighter know-how alive as the U.S. Air Force, Navy and Marine Corps buy F-35s in large numbers. The Air Force in its wish list for the futuristic warplane cited greater reach, persistence, survivability, situational awareness, weapons effects and "human-system integration." In the twelve year gap , the US Airforce could get by with a small squadron of F-22s, a larger squadron of inferior F-35 Lightning II, and pilotless combat drones like the Predator and its successor the Reaper.
The J-20 is larger than the F-22A or the Russian Pak-Fa. It is said that the cyber attacks on the US that cost US 40 billion, was to get F-117 Nighthawk blueprints for the J-20. It is said that F-117 Nighthawk elements have went to china in the 1999 Kosovo war. The idea of Chinese reverse-engineering F-117 debris to understand technology is plausible. The idea that the J-20 has 30 years of Russian technology built into it and some F-117 technology would look true. J-20 will be ready in 2017.
The J-20 is of a conventional layout as fighters go - though it is worth mentioning that the size of the J-20 is greater than that of the American F-22 or Russian Sukhoi T-50/PAK FA development. Taken as a whole, the J-20 appears to be the body of the experimental, delta-wing Mikoyan Project 1.44 aircraft with the nose section of a Lockheed F-22 Raptor. The fuselage is noticeably long and wide presumably for the use of large amounts of internal fuel stores, advanced avionics capacities and large internal weapons bays. The cockpit is held well forward in the design and the engines are fitted in the rear. Canards are set along the forward portion of the fuselage and serve to provide improved vortex lift for the airframe body. Likewise, the use of the anhedral set main wing assemblies works in conjunction with these canards to help improve lift. The main wing assemblies, each sporting anhedral, are delta in arrangement and the vertical fins on the tail noticeably canted outwards. The vertical tail fins and forward canards are all-moving surfaces, hinged at internal joints, and help in providing for an agile airframe. There are two small ventral fins near the trailing edge of the main wings, outboard of either engine. The engines are buried deep within the middle and aft portions of the fuselage, aspirated by a set of inward slanted intake openings to either side of the cockpit. The intakes are preceded by a bulbous chine mount that is contoured rather elegantly to either cockpit side. From the first few initial photographs of the J-20, the engines seem to exhaust through a pair of conventional nozzles so no thrust vectoring is apparent in the prototypes. Stealth plays an important role in the design of the J-20 so plasma technology is used in the various exposed moving joints of the vertical tail fins and forward canards. The undercarriage is wholly conventional and made up of a tricycle landing gear arrangement featuring a single-wheeled nose leg and a pair of single-wheeled main landing gear legs. The nose leg retracts forward under and aft of the cockpit floor while the main legs retract forward into the sides of the fuselage. Of note here is the "saw-tooth" edges of the landing gear doors - consistent with the stealth design philosophy of the F-22 Raptor.
Internally, the J-20 will sport the latest in Chinese fly-by-wire technology and advanced fire control and engine management features. The pilot will most likely control the aircraft through a traditional HOTAS (Hands on Throttle and Stick) arrangement and have access to a single, wide-angle, full-color "glass" cockpit liquid crystal display ala the Lockheed F-35 Lightning II. In conjunction with the LCD may be a helmet-mounted sight system for the pilot. A wide-angle HUD (Head-Up Display) will provide pertinent performance and mission information to the pilot above the instrument panel.