The X-29 is the first ever aircraft to employ the concept of a forward swept wing. This concept was originally concieved by 1930's German scientists. Later in the decade they built a prototype, but it was grounded due to unstability. The X-29 comes from this idea, and in 1984 it was flown for the first time. It too had stability problems, but this time there were computers on board which correct the planes flight path 42 times a second. The project was ended later that year, but was then restarted in 1989 after renewed interest.