X-44 MANTA Multi-Axis No-Tail Aircraft
The X-44 designation is said to be reserved for possible NASA full-scale manned tailless flight control demonstrator. The X-44A has been referred to as the MANTA, or Multi-Axis No-Tail Aircraft. A conceptual drawing of an X-44 is said to resemble a tailless F-22, and is said to be based on an F-22 airframe, engines and systems. The X-44A thrust-vectoring test aircraft would have pitch/yaw vectoring nozzles and would not only be tailless but would have no moveable aerodynamic surfaces.
The X-44 MANTA is a converted delta-winged F-22 which uses vectored thrust as its sole means of control. The plan is to convert an F-22 so that it uses its thrust vectoring nozzles for its flight control, without rudders, stabilitors, or ailerons. MANTA could be used to validate the planform for the FB-22. MANTA flights could begin by 2006.
Thrust vectoring -- the ability to turn the jet exhaust -- allows an aircraft to create forces with its motors similar to the forces created by aerodynamic surfaces such as flaps, rudders & stabilators. The result would be a structurally simple, light airframe, with increased fuel volume and fewer gaps to cause stealth problems. An X-44A feasibility study is in progress, with a team including AFRL, NASA, Lockheed Martin and Pratt & Whitney.
The X-44A is unlikely to fly before 2007, though the F-22 program will retire the first and second flying prototypes in 2001-02.