During the Vietnam War radar-guided surface-to-air missiles began to take an increasingly heavy toll on American aircraft. As a result of these losses, American planners began seeking a way to make an aircraft invisible to radar. The theory behind their efforts was initially developed by Russian mathematician Pyotr Ya. Ufimtsev in 1964. Theorizing that the radar return of a given object was not related to its size but rather its edge configuration, he believed that he could calculate the radar cross-section across a wing's surface and along its edge.

Utilizing this knowledge, Ufimtsev conjectured that even a large aircraft could be made "stealthy." Unfortunately, any aircraft taking advantage of his theories would be inherently unstable. As the technology of the day was incapable of producing the flight computers necessary to compensate for this instability, his concepts were shelved. Several years later, an analyst at Lockheed came across a paper about Ufimtsev's theories and, as technology had sufficiently advanced, the company began developing a stealth aircraft based on the Russian's work.