Jet fighters first made an appearance in the German Luftwaffe during World War II, but the technology had come a long way by the time the Korean War started in 1950. At first, the North Korean air forces were flying Soviet-built propeller-driven fighters, and the United States forces were flying American-made P-51 Mustangs and Vought F4U Corsairs. As the war dragged on, both sides got substantial upgrades.  When the Korean People's Air Force started flying the MiG-15, it was clear that...