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