Differences between F-22 and YF-22

Though many mistake one for the other, the F-22 has many substantial differences from the YF-22 prototype. The F-22 forebody was reshaped, the cockpit (a) was moved forward, and the inlet (b) moved aft to improve aerodynamics and pilot visibility. The radome (c) shape changed to provide better radar performance. The F-22 has no pitot boom (d). (The pitot on the YF-22 was purely a flight test piece of hardware.) A lower-sweep, higher-span wing (e) with a thinner section improved maneuverability without diminishing supercruise capability. Wind tunnel tests after the prototype design freeze resulted in smaller verticals (f), larger and reshaped horizontals (g), and the elimination of the dedicated speedbrake (h). Numerous optimizations of the internal systems and structure changed vent and access locations and extended the structural keel beam through the main weapons bay. The main landing gear changed from forward-retracting to side-retracting to reduce the weight of the gear and make more efficient use of the volume in the fuselage. This change allowed the side weapon bays to move aft, the inlets to be shortened, and the vertical tails to be made smaller.

 The overhang of the horizontal tail was removed by clipping the inboard end off to match the end of the booms (i). The refuel receptacle (j) was redesigned, eliminating the bump in the contour. (The YF-22 used a receptacle from the F-117.) The aileron sweep line (k) was changed to match the flaperon to improve roll control. The leading edge flaps (l) were extended farther inboard. The area now occupied by the flaps near the fuselage was previously reserved for dual infrared search and track sensors. The wing tips were clipped (m) to integrate antennas. The wing attach joint and associated fairings were modified. (The YF-22 used a tension joint like the F-16; the F-22 uses a shear joint like the F-15.) Spoilers for the side weapon bays were eliminated. The main weapon bay spoiler was changed to a smaller, internally stowed design. The main weapon bay doors were changed from a bi-fold design to single-fold. The large external scoop and fairing for engine bay ventilation was eliminated. The external contours of the exhaust nozzles (n) were curved to reduce weight. Several bumps were added to the external surface for electronic warfare, communication antennas, and sensors. The canopy frame design was simplified. Many external and internal features were added to improve accessibility and maintainability.
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