Background
The F-15 emerged from a design study started in the early 1960s called the FX program. When the missile centered American designs of the late 1940s and 50s proved vulnerable to seemingly less advanced Soviet Migs over Vietnam, and after the unveiling of the Mig 25, the U.S. started a concentrated effort to build the next generation of fighters. Centered around the energy maneuverability theory the new designs would have very high thrust to weight ratios. That’s what the F-15 (and F-14, F-16 and F-18) would eventually achieve. Built around two Pratt and Whitney F-100 engines that allow the aircraft to accelerate in the vertical, the F-15 and associated new generation U.S. fighters outclassed any opposition at the time. In 1976 a specially prepared F-15 called the Streak Eagle broke eight time to climb records previously held by the Mig 25. A year prior the Japanese Self Defense Force came looking for a replacement for their F-104 and F-4s.