Stealth airplanes are aircraft with special design features that make them less detectable visually, thermally, audibly, and on radar. They are not invisible by any means, but they are far less identifiable than conventional aircraft. Such aircraft are part of a continuous race between stealth technology and detection technology in warfare.
Stealth airplanes were initially developed by Lockheed in the Have Blue prototype project. The first two airplanes of this kind flew between 1977 and 1979. The design approach of the aircraft was unique in that it centered around the engineering goal of reflecting radar waves away perpendicularly, rather than making the aircraft aerodynamic. Reflecting away radar waves is necessary to avoid bouncing radar waves back for the enemy to detect on the ground. These airplanes are not designed for speed or maneuverability, but rather for stealth. Both early prototypes crashed because of their poor stability.
Though usually painted black, this is not the optimal color for an airplane to be stealthy. Counterintuitively, at the altitude that most such airplanes fly, a white bottom would be the least visible. The black color is for the purpose of making the aircraft look more intimidating.
Although stealth airplanes have become less stealthy in recent years due to better radar scanning techniques, the countries of Russia and the United States continue to pursue their development. Anti-stealth detection technologies exist, but their effectiveness is uncertain, they require an abundance of computing power, and the detectors are not mobile.
Because they are designed for avoiding detection, stealth airplanes would be helpless in a dogfight. Their primary purpose is for spying or to initiate a first-stage attack on enemy defenses, softening them up for more conventional non-stealthy forces.
The first stealth airplane was the F117 Nighthawk, descendant of Lockheed's Have Blue project. Others include the F-22 Raptor and the B-2 Spirit bomber, the most expensive airplane ever built, at $2.2 billion. The latter was built for Cold War operations, capable of carrying nuclear as well as conventional payloads, and would probably have been the primary bomber for nuclear attacks if a war broke out between the US and USSR.
