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.