Patent ID: 6974105

Claim:
In a VTOL airplane capable of a vertical takeoff and landing mode (VTOL), an autorotation mode wherein the airplane is capable of a steep but controlled and safe descent by means of a large-diameter lift rotor in an absence of engine power, as well as an efficient high-speed horizontal cruising mode, the combination comprising: a pair of wings disposed on opposing lateral sides of the airplane for supporting the airplane in the horizontal mode, said wing having a wing tip and a wing root, a horizontal stabilizing surface and a vertical fin disposed at a tail end of the airplane for providing necessary aerodynamic stability, a fuselage having a top, a bottom, a front section, a tail section and a longitudinal axis forming a center line running from the front section toward the tail section, means for controlling said airplane in the VTOL mode and in the autorotation mode in all three typical pitch, roll, and yaw axes, means for controlling said airplane in the horizontal cruising mode typical for a conventional airplane, comprising of ailerons, rudders and elevator. vertical lifting means comprising of: at least one tiltable lift rotor mounted on top of a power pod having a significant length, said tiltable lift rotor having a plurality of elongated and slender rotor blades radially arranged around a tiltable rotor axis, said tiltable rotor axis traverses the length of the power pod, said tiltable rotor axis is tiltable between a vertical orientation for providing vertical lift in the VTOL mode, and a horizontal orientation, for use in the horizontal cruising mode, wherein said tiltable lift rotor blades are disconnected from power and are allowed to rotate at a minimum rotational rate generally sufficient for maintaining structural integrity of the rotor blades in spite of strong force of relative wind in a high-speed cruise, rotor transformational means for transforming the orientation of said tiltable lift rotor between the vertical orientation and the horizontal orientation, engine powering means connected to said power pod, said power pod having a top end mechanically connected to said tiltable lift rotor for powering said tiltable lift rotor, said power pod is pivotably mounted to a structure of the airplane allowing tilting motion of said tiltable lift rotor, means for disconnecting said engine powering means from said tiltable lift rotor, for use in the horizontal cruising mode, wherein said rotor blades are allowed to rotate at said minimum rotational rate whereby significant drag reduction and rotor blade integrity can be maintained, horizontal propulsion means structurally separated from said tiltable lift rotor for providing horizontally-oriented thrust for use in the horizontal cruising mode, whereby higher cruise efficiency can be obtained than if said tiltable lift rotor is also used as horizontal propulsion means.