Abstract: Conventional cantilever wings of a tiltrotor aircraft are replaced by a joined-wing configuration that eliminates some major speed-limiting constraints of prior tiltrotor configurations--thereby allowing operation into the intermediate speed range of roughly 350 to 450 knots. Joined wings offer relatively rigid, stiffened support for the additional wing-mounted hardware, and also stiffen the system to resist rotor flutter and other sources of aggravated loading, that are characteristic of tiltrotor craft. Joined wings provide this advantage, however, while simultaneously significantly lowering airfoil thickness--and thereby importantly increasing the drag divergence Mach number, and hence the maximum speed. In addition, some joined-wing configurations have significantly lower rotor-wing downwash interactions in hover.

Abstract: An aircraft having a fuselage and a pair of first airfoils in the form of wings extending outwardly from the vertical tail and a pair of second airfoils in the form of wings extending outwardly from the forward portion of the fuselage at a lower elevation than the first airfoils. The second wings extend rearwardly having a positive dihedral so that the tip ends of the second airfoil are located in close proximity to and may overlap the tip ends of the first wings. The pairs of wings along with the fuselage present a double triangle or diamond shape in both front elevational view and top plan view. A winglet structurally connects the tip ends of the corresponding first wings and second wings, and these winglets have airfoil surfaces which extend vertically substantially beyond the tip ends of the first and second wings in order to minimize the effects of induced drag and also to augment directional stability of the aircraft.

Abstract: An apparatus for controlling the distance between a vehicle to which it is attached and a surface over which the the vehicle may be moving. The apparatus includes a cable and a sheet member which in a first mode is in contact with the surface but in a second mode is out of contact with the surface. Because of design, the sheet member induces a greater tension in the cable when in the second mode than when in the first mode; the increase in tension may be used to actuate a control or indicating devices on the vehicle to maintain the distance within desired limits.

Abstract: An aircraft of the Canard type in which a first airfoil is attached to an aft fin portion of the fuselage at a higher elevation than a second airfoil which is attached to the fore portion of the fuselage. The second airfoil extends outwardly and rearwardly to meet the first airfoil whereby a triangular configuration is formed in plan view and in front elevation view. The airfoils may be flexible; simple cable controls may be provided to control the aircraft so that even inexperienced pilots can easily operate the aircraft. The triangular configuration ensures a lightweight and inexpensive yet rugged and strong aircraft. The aircraft may also include a split rudder and may be hinged for folding to facilitate storage and transportation.