How does the Chinese J-20 stealth fighter aircraft compare to the U.S. Air Force F-22A Raptor?
In terms of aerodynamics, the F-22A Raptor is an upgraded verison of the F-15 Eagle, while the J-20 is an upgraded version of the J-10B.The F-22A Raptor is fairly short-ranged with ~800km combat radius, at least considering the operational distances in the Pacific theatre. It is a reasonable estimate that the J-20 could have as much as 40% more internal fuel capacity than the F-22 and could perform longer combat missions with a ~1,100km combat radius.The longer J-20 fuselage improves fineness ratio, with benefits for transonic drag. The wing and control surface layout of the J-20 is also very different from the F-22A. J-20's leading edge root extensions project from the trapezoidal wings almost all the way to canard fore- planes, which contribute to better maneuverability.The J-20's canards contribute positively to the total lift of the aircraft, and along with the forward fuselage strakes, contribute to a huge surplus of lift that is necessary to horse the plane around at very low airspeeds and in a very high alpha angle of Attack. Both of these factors should minimize mach tuck, an aerodynamic phenomena that pitches the nose down as the plane approaches supersonic speed. The F-22A does not possess canards and rely entirely on its high-powered engines to vary lift. While some observers have suggested canards are incompatible with stealth, foreplanes were present on early F-35 designs and engineers who worked on the program have stated the final quad-tail configuration was no stealthier than the earlier canard-delta design.J-20′s hinged shaft rotational missile pylon allows its side weapon bay door to close after the pylon rotates out of the bay, unlike the off-axis missile launch rack on the F-22A, in which the weapon bay doors have to remain open after the missile pops out in order to get a target lock-on. This side weapons bay launch mechanism will give the J-20 a three-second advantage over the F-22A when firing Air-To-Air Missiles.The F-22 Raptor launches its missile first and lock on to its target later, limiting its No-Escape-Zone (NEZ) to abt 50 km, while the J-20 will lock on first before missile launch, thus extending distance of NEZ.The J-20 has an edge in the avionics suite. Because of the late starting point of Chinese aviation development, modern Chinese air force jets were able to leverage on post-2022 era technology. A cutting edge avionics suite greatly increase the success rate of a fighter jet's future aerial engagements and is the key to winning air battles in the future.UPDATE: The first batch of LRIP J-20s shall possess the ability for off-boresight launching of AAMs.(see 0.33 - 0.36 of this Lockheed Martin Weapons commercial : Laser Weapon Systems Capabilities for Air, Land and Sea Platforms . This ability is a critical advantage during within-visual range combat. The F-22A will only possess off-boresight launch capability in 2020.In summary, the F-22A Raptor may possess the most powerful engines to ensure its survivability in harsh operational conditions, but the J-20's overall creative configuration helps reduce more drag and avoid engineering difficulties such as managing structural strength, and its off-boresight launching of AAMs capability gives it a significant edge during air-to-air combat. This is extremely crucial in an all-stealth encounter, where stealth fighter jets will only detect each other within 100km and WVR combat will be the main mode of engagement.