Chinese researchers claim that the US Air Force's B-21 Raider stealth bomber can be taken down by PLA's hypersonic missiles. In simulated war games, a B-21-like stealth platform and its companion drone were shot down by China's air-to-air hypersonic missiles. The B-21 Raider, despite its radar signature as small as a mosquito, could pose a severe threat to China's air defense. China has developed hypersonic missiles with special features to track and kill stealth aircraft. The Chinese military is also developing a large and advanced stealth aircraft.