Abstract: Runway length requirement for take-off and landing of an aircraft is reduced by taking advantage of dynamic lift overshoot, and in some cases, dynamic stall. In take-off and landing, the angle of attack is rapidly increased so that the lift coefficient exceeds the maximum predicted by the steady flow lift curve. By increasing the angle of attack at an appropriate rate, the increased lift coefficient can be maintained, without loss of control, until the aircraft touches down in the case of a landing, or until the aircraft can begin a normal climb, in the case of take-off. A low aspect ratio lifting body is preferred because of its more gradual stall behavior, and the potential to use dynamic stall for further deceleration before touchdown. Vortex fences can be oscillated to delay the onset of stall, and, in cruise, to energize the boundary-layer and reduce drag and/or control roll and/or yaw.

Abstract: Runway length requirement for take-off and landing of an aircraft is reduced by taking advantage of dynamic lift overshoot, and in some cases, dynamic stall. In take-off and landing, the angle of attack is rapidly increased so that the lift coefficient exceeds the maximum predicted by the steady flow lift curve. By increasing the angle of attack at an appropriate rate, the increased lift coefficient can be maintained, without loss of control, until the aircraft touches down in the case of a landing, or until the aircraft can begin a normal climb, in the case of take-off. A low aspect ratio lifting body is preferred because of its more gradual stall behavior, and the potential to use dynamic stall for further deceleration before touchdown. Vortex fences can be oscillated to delay the onset of stall, and, in cruise, to energize the boundary-layer and reduce drag and/or control roll and/or yaw.

Abstract: An aircraft is composed of two elongated inflated, flexible tubes diverging from each other from a nose of the aircraft toward a trailing edge. First and second membranes span the upper and lower surfaces of the tubes respectively to provide upper and lower airfoil surfaces. One of the two membranes is connected to a length of cable extending from the tip end of one tube to the tip end of the other at the trailing edge. Trim is provided by a fixed flap composed of flexible membrane stretched between the cable and another, parallel cable. The nose ends of the tubes are secured to a propulsion motor-mounting plate assembly at the nose end of the aircraft, and the opposite ends of the tubes are secured to plates at the ends of the trailing edge. The cables are secured to the plates at the ends of the trailing edge, and these plates are also used to support horizontal stabilizers.

Abstract: In a novel hovering aircraft, an airfoil blade structure rotatable about a vertical axis comprises a set of upper blades and a set of lower blades, all having variable lift, the upper blades converging toward the lower blades from root to tip. Struts, located inboard of the blade tips, keep the tips of the upper and lower blades separate from each other to reduce interference effects, and also support motors and propellers.

Abstract: An airborne surveillance platform utilizes a low aspect ratio delta-shaped aircraft having a radar-transparent hull. The antenna is located within, and stationary relative to, the hull. The antenna comprises planar or linear phased arrays arranged to scan in a continuous 360 degree pattern in all azimuthal directions or in a continuous 180 degree pattern in all forward azimuthal directions. Planar phased arrays can be arranged to scan in a continuous pattern in the range from zenith to nadir or in portions of that range. In the case of forward direction scanning, the antenna arrays are located immediately inside the radar-transparent leading edges of the aircraft hull, thereby allowing a large cargo space within the hull between the antenna arrays. Access to the cargo space is provided through an opening in the trailing edge.

Abstract: An airborne surveillance platform utilizes a low aspect ratio delta-shaped aircraft having a radar-transparent hull. The antenna is located within, and stationary relative to, the hull. The antenna comprises planar or linear phased arrays arranged to scan in a continuous pattern in all azimuthal directions. Planar phased arrays can be arranged to scan in a continuous pattern in the range from zenith to nadir or in portions of that range.

Abstract: An unexpectedly high augmentation of aerodynamic lift for a given amount of power in STOL operation of a V/STOL aircraft is achieved by combining the unique features of a lifting body with those of a "jet flap", i.e. an aerodynamic mechanism in which a slipstream is directed over a deflected flap. Specifically, a movable flap is located on the trailing edge of the lifting body, and a tiltable propeller, which propels the aircraft in the normal manner in cruising, may be tilted, in low-speed flight, in order to direct air toward the leading edge of the flap and over the upper surface thereof. The movement of a large mass of air at a higher velocity over the upper surface of the flap maintains the air flow over the flap in an attached condition, and entrains and energizes the lower-velocity boundary layer on the airfoil forward of the flap, thereby producing an augmentation in lift.