Without doubt, the most exiting combat aircraft of the early 21st century is the Lockheed Martin F-22 Raptor. A far different aircraft from anything preceding it, the F-22's development history reflects the many problems, both technological and financial, than can beset an advanced system of its kind.

In the late 1970s, the USAF identified a requirement for 750 examples of an Advanced Tactical Fighter (ATF) to replace the F-15 Eagle. The goal was to produce a tactical aircraft that would remain viable for at least the first quarter of the 21st century. This aircraft would have a range 50-100 per cent greater than the F-15, be capable of short take-off and landing on damaged airfields and be able to engage multiple targets at once, beyond visual range. It must incorporate stealth technology and supercruise. Supercruise meant that it could maintain supersonic speeds without afterburners. In addition this paragon of fighter aircraft would have to be operated by a single pilot and be able to survive in an environment filled with people, both in the air and on the ground, whose sole purpose would be to destroy it.

One of the first research projects produced the YF-16 which flew in 1976-77 and demonstrated the decoupling of aircraft flight path and attitude. What this meant is that the aircraft could skid sideways, turn without banking, climb or descend without changing its attitude and point its nose up or down, or right or left, without changing the direction of its original flight path. Another development was the mission adaptive wing (MAW), in other words, the wing was capable of reconfiguring itself automatically to mission requirements.

In April 1991 it was announced that the F-22 by Lougheed coupled with the Pratt & Whitney F119 had won over five other design concepts. The P&W F119 develops 35,000 pounds of thrust (lbst) and is fitted with two-dimensional convergent/divergent exhaust nozzles with thrust vectoring for enhanced performance and maneuverability. The F-22 has two of these engines.

The F-22 combines many stealth features with nearly all its armament stored internally. The aircraft is designed for a high sortie rate, with a turn-around time of twenty minutes and its avionics are highly integrated to provide rapid reaction in air combat, much of its survivability depending on the pilot's ability to locate a target very early and kill it with a first shot.

For any air force, an ideal mix would be a majority of high-performance subsonic V/STOL aircraft, covered by a minority of supersonic interceptors. Many current combat aircraft are supersonic, multi-role and have a very short take-off capability. None, including the Harrier, have a true vertical recovery capability. The Harrier however and the F-22, between them, are as close as any design has come to fulfilling the description of an ideal mix. The limitations on further development are imposed by the astronomical costs of present day aviation research and development.

It was once suggested that, by the middle of the twenty-first century, the entire gross national product of a country like the USA would not be sufficient to develop a new combat aircraft, but that was before computer technology absorbed much of the strain of research and development. The world's major defense research agencies are, through computer analysis and simulation, currently studying the designs of agile aircraft for the year 2050, a generation beyond the F-22.

In the future, use may be made of Remotely Piloted Vehicles (RPV) in air combat, just as they are now being used for reconnaissance duties in Iraq and Afghanistan. Meanwhile, the agile combat aircraft and fighter pilot, will continue to rule tomorrow's skies.