Grumman Aerospace Corporation

David F Gebhard

Robert W Kress

An unmanned aircraft is provided which dual turbo shaft engines diving contra-rotating propellers. A bow plane provides pitch control during normal aircraft cruising. The contra-rotating propellers generate a slipstream for wing and tail sections that permit the aircraft to execute hover without the use of complicated tiltable rotor or jet assemblies.

Unmanned boom/canard propeller v/stol aircraft

A tilt wing VTOL aircraft has an upper wing with a leading edge, a trailing edge, an inboard area adjacent the fuselage, spaced opposite end tip areas and an upper surface. The wing is pivotally mounted on the fuselage for rotation from a cruise position in which the upper surface of the wing is flush with the upper surface of the fuselage to a hover position in which the wing is perpendicular to the upper surface of the fuselage. The wing has a forward portion in the leading edge of the inboard area affixed to the fuselage and cut out of the wing and an aft portion in the trailing edge of the inboard area affixed to the fuselage and cut out of the wing. Thus, when the wing is in its cruise position it is whole, including the forward and aft portions, whereas when the wing is in its hover position it has a forward cutout at its leading edge in the inboard area corresponding to the forward portion and an aft cutout at its trailing edge in the inboard area corresponding to the aft portion so that the spanwise wing lift distribution is diminished when the wing is in a position other than its cruise position. The forward and aft cutouts produce a vortex along the sides of the fuselage which results in the spanwise wing lift distribution being diminished when the wing is in a position other than its cruise position. This vortex increases the wing tolerance to angle of attack and thus reduces the requirement for propeller bending of the air flow during mid-transition speeds. It also reduces the intensity of center section buffet.

Tilt wing VTOL aircraft

A telescoping energy-dissipating oleo landing gear shock strut set which can provide both the main landing gear and forward landing gear function, and which is affixed to an airplane, is restrained in an unenergized, shortened condition. A high pressure gas charge is then provided between the extendible element of the strut and the element affixed to the airplane. Early in the takeoff run, the charge gas in the forward strut is released so as to jump the nose and rotate the airplane to a high angle of attack appropriate for takeoff. Subsequent to this rotation, but before the conventional takeoff speed is reached, the charge gas in each of the main struts is released to impart a vertical velocity to the entire airplane, thus jumping it into the air. Both the forward strut and main struts incorporate a hydraulic flow bypass function, so that the landing shock dissipation function does not compromise the aforesaid energy release. The struts also incorporate valves to discharge enough residual gas immediately at the end of the jump stroke so that the landing energy dissipation mode is not compromised.

Growing community of inventors

Northport, NY, United States of America

David F Gebhard