The story of the F-15 really begins in
Korea on December 7,
1950, when
Lt. Col. Bruce H. Hinton scored the first
air-to-air kill for the
F-86 Sabre. For the first time in the
conflict, the
Americans had an aircraft that could counter the threat from the
Soviet MiG-15. At the end of the conflict, the
USAF had achieved a 10:1 kill ratio and effectively owned the skies.
Energy
On paper, the F-86 was barely a match for the more agile MiG. Initially, the success of the Sabre was chalked up to the superior training and tactics of the American pilots, however the tactics used were originally designed for WWII-era piston aircraft, and American pilots were often rotated off the front lines. Years later, Sabre pilot Col. John Boyd would begin to decipher this riddle.
In 1953 Boyd became flight commander and tactics instructor for his squadron. At the time, the USAF was dominated by the "bomber generals" at SAC, who thought that the age of the dogfight was over. The Air Force had no formal doctrine regarding air-to-air combat. By 1960, Boyd would literally write the book on dogfighting in the jet age, and in the process discover the secret to the F-86's success.
Later that year, Boyd began attending Georgia Tech. He had a lot of ideas about air-to-air combat, but lacked the technical knowledge to solidify his theories. In 1962 he met Tom Christie and began working on what would later become his Energy-Maneuverability Theory. Boyd thought that for an aircraft to achieve and maintain the advantage in a fight, it would have to be able to increase its energy more rapidly than its adversary, and therefore should have a higher thrust-to-drag ratio. This and other factors Boyd believed could determine an aircraft's chances of victory in a fight. He concluded that the F-86 was a successful fighter because of its ability to easily transition from one maneuver to another. Additional factors like the high visibility of the bubble canopy and the easy stick clinched its role as the dominant fighter of the war.
Commonality
In 1961 Secretary of Defense Robert McNamara began the Tactical Fighter Experimental (TFX) program. The TFX was to be a multi-role fighter/bomber designed to meet the disparate needs of both the Air Force and the Navy. At the time, the Navy was busy working on the AIM-54 Phoenix missile and what would become the F-14 Tomcat, and wanted nothing to do with the TFX. Meanwhile, the Air Force was sick of having Navy aircraft like the F-4 Phantom II foisted on them, and wanted to take control of the TFX program.
The TFX was a heavy, swing-wing aircraft capable of moving fairly fast, provided it wasn't turning. It was complex, expensive, and unsuited to the needs of either branch. Though it would eventually enter service with the Air Force as the F-111, the Navy rejected it outright. TFX was floundering, and the USAF still didn't have a winner.
To make matters worse, the war in Vietnam was not going well for the Air Force. In a dogfight, the F-4 couldn't keep up with the tiny MiGs. The Sparrow missiles the Phantom carried were designed to be used against bombers, and were nearly useless against fighters. Rules of Engagement required visual identification of enemy aircraft before action could be taken, and at such close ranges if its missiles failed, there was little the F-4 could do- it had no gun.
The Air Force needed help, when in 1965 Boyd delivered his E-M presentation to two Air Force generals. Not long after, Boyd was called to the Pentagon.
Eagle
On July 9, 1967, the Soviet Union unveiled the MiG-25 at an air show in Moscow. In October, the Foxbat would set a speed record of 1,852 miles per hour. The Air Force, already having difficulty countering the existing Soviet threat, desperately needed a new fighter. So the F-15, the first air-to-air combat aircraft requested since the F-86, was born.
Lessons learned from the TFX, Vietnam and Boyd's theories dictated the design requirements for the F-15. For the first time in years, the top speed of the aircraft was less important than its maneuverability. While missiles would still be the primary weapon of the fighter aircraft, they were useless if you couldn't attain a favorable firing position on your enemy. Boyd's E-M theory described a successful fighter as being lightweight, possessing a large wing area and producing as much thrust as possible.
In 1968, at the behest of DoD Research and Engineering Director Dr. John Foster, NASA was invited to participate in the design competition. Engineers at the Langley Research Center generated a number of designs, and advised the primary contractors on their discoveries. One of these designs, the LFAX-8 was adapted by McDonnell Douglas into the aircraft that would eventually win the contract. Engineers at Langley continued to participate in the design of the aircraft, fine-tuning the aerodynamic characteristics of the fighter.
Designers continued to innovate inside the cockpit as well. The Air Force's tendency towards gadgetry, while not halted, was finally being tailored to the needs of the pilot. The Heads Up Display (HUD) and Hands On Throttle And Stick (HOTAS) systems allowed the pilot to keep his eyes outside the cockpit at all times. The HUD provides mission data projected in front of the pilot while HOTAS allows the pilot to control all aspects of the aircraft without ever looking down.
When the F-15 first flew in 1972 it already far outclassed anything in the sky. It has taken 25 years for any aircraft to approach its performance. As mentioned above, it has a spotless combat record, scoring 101 kills with 0 losses. The Eagle's first kills came on July 27, 1979 when the IAF downed 5 Syrian MiG-21s. On February 13th, 1981 an F-15 was finally given the opportunity to be tested against the feared MiG-25, and won. It was soon learned that if a Foxbat pilot wanted to survive a fight with an Eagle, he would have to run.
The C variant is soon to be phased out in favor of the F-22 Raptor. However, the A, B, D and E variants will continue service with the Air Force and Air National Guard.