Only a few of these were built, but have provided a springboard into more advanced designs, such as this swept-wing, twin-engine Cutlass, a real departure from the conventional. Designed from the outset to use a new idea called "the afterburner." Looking more like a rocket ship than an airplane, it could shoot up to 45,000 feet, and almost break the sound barrier. The jet age was just getting a good start when the insatiable appetite of the aggressor lashed out with teeth of Steel, Korea. A byproduct of the Cold War became a hot testing ground between freedom and oppression. It began June 25th, 1950 at the 38th parallel, and ended July 28th 1953 at the 38th parallel. Korea was the baptism of fire for the jet. High altitude, sometimes, supersonic dogfights raged through the air corridor called "MiG Alley." Speed, the asset of the jet and aerial combat, was its detriment as a ground support weapon. So the old warhorse, the Corsair, thought obsolete in the jet age, was again called back to do the job its propeller-less cousins were unable to do, get in close to the ground troops and stay on the target longer. At the close of the Korean War, when the swept-wing Cutlass was on the downhill side of the production line, a new design emerged from the drawing board of the Vought engineers, the F8U crusader. It was a farsighted design that carried naval aviation from the subsonic to the supersonic age.