The F-22 Raptor has a wonderful design but its production was very short lived with a little less than 200 units produced. It is not really a good idea to let go of a great idea because they always find a way to be useful. Such is the case of the X-44 Manta which was developed from the design of the F-22 Raptor.
The X-44 Manta is a conceptual aircraft that was based on the design of the F-22 Raptor. This jet used a delta-shape in order to show what the jet can perform without tailpipes included on the airframe. The main idea of the X-44 Manta was to use thrust-vectoring as the sole source of control for the aircraft.
“Thrust vectoring—the ability to turn the jet exhaust—allows an aircraft to create forces with its engines similar to the forces created by aerodynamic surfaces such as flaps, rudders, and stabilators.”
– American X-Vehicles: Centenial of Flight Edition
It had an innovative design but the Manta never got off the ground and funding for the program was halted in 2000. The X-44 remains just an idea, but it is still an interesting concept to consider.