Some warplanes remain in service for a long time because they have unique capabilities that are not recognized until long after they are retired from military service. One current example is the American F-104 jet fighter, an aircraft that entered service in 1954, nicknamed “Starfighter”, and some served with foreign air forces until 2004. The U.S. Air Force only bought 296 of them and retired the F-104 in 1969. A few remained in use by National Guard (reserve) units until 1975.
For the Americans, the problem was that its flight characteristics making the F-104 impressive as a short-range interceptor and fly very fast to a high altitude was made possible by limiting range, maneuverability and payload. As a result there were a small number of nations that befitted from the F104’s unique qualities and none of them were in the Americas.
By the 21st century, more than sixty years after the F-104 first flew, it was found to be useful for space flight research. An F-104 can get new SLV (Space Launch Vehicle) components to a very high altitude, very quickly so that the new component can be monitored in “near space” conditions. The flight characteristics of the F-104 were found useful in testing many other aircraft or missile components.
The two-seat F-104 trainer can also provide a lot of revenue from giving civilians a brief flight experience in one of the more spectacular jet fighter designs of the 1950s. Some licensed pilots will pay to fly the F-104 as part of a program that gets them certified to pilot an F-104. This is a hobby with many pilots qualified to fly non-military aircraft but, because of prior service as a military pilot or just a love of flying, will spend the time and money to qualify in older warplanes. The F-104 is one of the oldest jet fighters that is still available for training and other services for NASA (National Aeronautics and Space Administration), which has long employed retired military aircraft for various tasks.
Starfighters Aerospace, the only commercial operator of the F-104, was founded in the 1990s using three F-104s retired by the Norwegian Air Force in the 1980s but kept in storage. The U.S. has a large number of historical aircraft restoration groups and the F-104 was one older jet fighter that had not received much attention. That changed once the Cold War ended in 1991 and became history worth studying. Flight enthusiasts had been a growing group and paid to attend air shows where flight demonstrations of historical warplanes was a major draw. After the 1990s Starfighters Aerospace found more and more demand for operational F-104s. As a result, Starfighters Aerospace is expanding its operational F-104s from four to at least seven and possibly nine or more.
The F-104 was designed to be, like the MiG-21, a second-generation jet fighter. The F-104 first flew in 1954 and entered service in 1958. Most of the 2,578 built in the 1950s and 60s were used by NATO members, especially the ones in Europe who had need of an interceptor that could quickly get to high altitude to confront Russian aircraft. The problem with the F-104 was that it was a great interceptor in Europe, where the enemy bases were close and time limited to intercept. But for North American NATO members United States and Canada, air defense required fast jets that would stay in the air longer and had more time to reach combat altitude. It was hoped that the F-104 could be useful for ground support, but many were sent to Vietnam in the 1960s and were less effective as ground attack and interceptors than other jets.
In the 1950s it was still possible to design, develop a new warplane into service quickly and F-104 was competing with several other new interceptor and multipurpose (interceptor and ground attack) aircraft like the F-4. The F-104 had become obsolete by the 1960s, at least for the USAF, about a decade after it first flew. NATO users found the F-104 worth keeping and these were not retired until the Cold War ended. The Italians were last to retire their F-104s, in 2004.
In the early 1950s the F-104 got a lot of positive publicity because it was fast, impressive looking and the Russians had nothing like it. The F-104 was a 13-ton, single engine fighter with a top speed of 2,400 kilometers an hour. That was twice the speed of sound (Mach 2) and had a max altitude of 15,000 meters (50,000 feet). Initial rate of climb, a key item for fighters and interceptors, enabled the F-104 to reach its max altitude in about a minute. For that reason, the F-104 was initially described as a “missile with a man in it”. There was some truth to that, but while guided air-to-air missiles could maneuver rapidly, they did so by generating G (multiples of standard gravity) forces that humans cannot handle. For that reason, the F-104 design did not allow much maneuver because a human pilot passes out at Mach 9 and missiles create G forces two or three times that while maneuvering.
To obtain the high speed and acceleration, payload had to be limited to less than two tons, including an internal multibarrel 20mm cannon. The payload was adequate for an interceptor, but inadequate for a fighter-bomber like the more maneuverable 28-ton F-4, which entered service three years after the F-104 and carried eight tons of bombs.
The F-4 was considered a third-generation jet fighter. The U.S. is still the first to introduce successful next-generation warplanes. The American F-22 and F-35 are "5th generation" fighters. The generation definition was all about advances in the design of jet fighters. The first generation was developed during and right after World War II (German Me-262, British Meteor, U.S. F-80, and Russian MiG-15). These aircraft were, even by the standards of the time, difficult to fly and unreliable, especially the engines. The 2nd generation (1950s) included more reliable but still dangerous to fly aircraft like the F-104 and MiG-21. The 3rd generation (1960s) included F-4 and MiG-23. The 4th generation (1970s) included F-16 and MiG-29. Each generation has been about twice as expensive (on average, in constant dollars) than the previous one. But each generation is also about twice as safe to fly and cheaper to operate. Naturally, each generation is more than twice as effective as the previous one.
A 5th generation F-35 costs six times more (taking inflation into account) than the 2nd generation F-104.