News Analysis How good is China’s most advanced fighter jet, the J-20? The J-20 is a “fifth-generation” combat aircraft, which ostensibly puts it in the same league as the U.S. F-22 and F-35. Fifth-generation fighters have certain common characteristics: very low visibility (stealth), the ability to fly at supersonic speeds without using an afterburner (called supercruise), and, most importantly, a highly advanced radar and suite of avionics and onboard computers for “networked data fusion,” enabling situational awareness in the battlespace. Theoretically, a fifth-generation fighter jet is nearly invisible to ground-based air defenses and other aircraft, and it can detect and attack threats from far away. At the moment, most modern air forces fly what we call “fourth-generation” or “fourth-generation-plus” (4G+) combat aircraft. Fourth-generation fighters include the latest versions of the American-made F-16 and F/A-18 and Russia’s Su-30, while the Anglo-German-Italian-Spanish Eurofighter Typhoon, the French Rafale, and the Swedish Gripen are …