Patent ID: 6974105
Filing Date: 2005-12-13
Classification: B64C

Abstract:
1. 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: 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.