Stealth features of the F-22

Taking a look at the F-22, quickly reveals the fundamental principles of a stealthy design as discussed earlier. Airframe features The F-22 has a low height triangle appearance from the front. This physical cross sectional view ensures a small signature from the front and low observability touches such as paint and materials, as well as little "W" shapes where straight lines might have appeared, all tend to break up the signature by absorption or redirection. The "W" shapes are found at numerous places on the stealth aircraft. For instance, in the forefront of the cockpit glass, there is a very apparent "W" shape. This reduces the radar energy reflected during a head-on pass to the radar emitter. The "W" shape is also found on landing gear doors, engine inlets and outlets, as well as other openings.

The leading and trailing edges of the wing and tail have identical sweep angles (a design technique called planform alignment). The fuselage and canopy have sloping sides. The vertical tails are canted. The engine face is deeply hidden by a serpentine inlet duct and weapons are carried internally.

Reduction of radar cross section of nozzles Is also very important, and is complicated by high material temperatures. The approach taken at Lockheed is to use ceramic materials. The ceramics may be either lightweight, parasitic sheets mounted on conventional nozzle structures or heavier structural materials forming saw-toothed edges.

Antennas

On-board antennas and radar systems are a major potential source of high radar visibility for two reasons. One is that it is obviously difficult to hide something that is designed to transmit with very high efficiency, so the so-called in-band radar cross section is liable to be significant. The other is that even if this problem is solved satisfactorily, the energy emitted by these systems can normally be readily detected. The work being done to reduce these signatures is classified.

Paint sheme

In order to make the F-22 disappear for the human eye on the ground, when in flight, special camouflage schemes have been developed. This way the plane will blend with the background sky as much as possible viewed from the bottom and disappear in the ground texture when seen from above.