B-2 Spirit stealth bomber of the USAF. Stealth aircraft are designed to avoid detection using a variety of advanced technologies that reduce reflection/emission of radar, infrared, visible light, radio-frequency (RF) spectrum, and audio, collectively known as stealth technology. Development of stealth technology likely began in Germany during World War II. Well-known modern examples of stealth aircraft include the F-117 Nighthawk, the B-2 Spirit, the F-22 Raptor,and the F-35 Lightning II.
The Horten Ho-229 flying wing fighter, first flown in 1944 by the Luftwaffe, rebuilt to exact specs by the model testing team at Northrop Grumman. The German prototype fighter/bomber designed by Reimar and Walter Horten and built by Gothaer Waggonfabrik late in World War II. It was the first pure flying wing powered by jet engines. Since the appearance of the B-2 Spirit flying wing stealth bomber in the 1990s, some describe the Ho 229 as "the first stealth bomber".