Aircraft engines. III

Prospective powerplant configuration advancements for tilt-rotor subsonic flight, supersonic commercial flight, and hypersonic flight are speculated upon, with a view to possibilities for the exploitation of novel materials and of such advanced fuels as liquid methane and hydrogen. Attention is given to the foldable tilt-rotor concept, which employs a hydraulic torque converter to engage the fan stage of the high-bypass turbofan engine used in forward flight after the tilt-rotor blades have been stowed, and several advanced cycles and turbomechanical configurations for cruise in the high supersonic regime and beyond, through the hypersonic regime, and into orbital velocity.