F-117

In 1964, Pyotr Ufimtsev, Russian mathematician, pioneered the idea that the level of the radar return from an airplane is related to its edge configuration, not its size. Basing on work by the German physicist Arnold Sommerfeld, Ufimtsev demonstrated that an aircraft radar signature can be reduced. By the 1970s, Lockheed analyst Denys Overholser found Ufimtsev's paper and F-117 Nighthawk was born as a black project, an ultra-secret Pentagon program.

The F-117 has a radar cross-section of about 0.001 m2 (0.0108 sq ft). The F-117A carries no radar and whether it carries any radar detection equipment is classified. The F-117 also reduces infrared signature, lacks afterburners, and limited to subsonic speeds.

However, the resulting design makes the aircraft aerodynamically unstable and requires constant flight corrections from a fly-by-wire flight system to maintain controlled flight. A pilot, who flew it while it was still a secret project, stated that when he first saw a photograph of the F-117, he "promptly giggled and thought to this clearly can't fly'". It has low engine thrust due to losses in the inlet and outlet, a low wing aspect ratio, and 50° wing sweep angle to deflect radar waves to the sides. Supercomputers made it possible for subsequent aircraft like the B-2 to use curved surfaces while maintaining stealth.

The 558 Nighthawk's pilots called themselves "Bandits", such as "Bandit 17", that where 17 is a sequential order of their first flight in the F-117. The aircraft was in use during Panama invasion, the Gulf War in 1991 and was first shot down in Serbia during on 27 March 1999 by an antiquate Soviet-made SA-3s (S-125 "Neva" ) anti-aircraft missile. The pilot was recovered by a United States Air Force Pararescue team. According to Serbian anti-aircraft unit commander, they spotted the aircraft on the radar when its bomb-bay doors opened, raising its radar signature. The Serbs invited Russians to inspect the aircraft's remains, compromising the stealth technology. Although officially retired, the F-117 fleet remains intact and some of the aircraft are flown periodically as of 2019.