Abstract: An unmanned aircraft capable of vertical takeoff, vertical landing, and/or flight in a hovering orientation is presented; its fixed-wing is positively-swept and of low aspect-ratio with suitable airfoils. The unmanned aircraft includes a thruster comprising two contra-rotating motors and propellers forward of the fixed-wing's leading-edge and a rudderless fin aft of the center-of-mass, all of which lie on the aircraft's plane-of-symmetry. Two elevons provide pitch and roll control. The unmanned aircraft can stand upright on its feet. A control system for aircraft with at least one wing is also presented. The control system includes a mount and attached thruster which lie on the plane-of-symmetry forward of the fixed-wing's leading-edge. A hinge axis approximately perpendicular to the aircraft's horizontal plane passes through the mount. The thruster rotates about the hinge axis for aircraft yaw control.

Abstract: A pitch control system characterized by a hub with at least two blade housings on the hub that are disposed around the hub axis. The blade housings have corresponding blades that engage with them. The blades spiral along housing longitudinal axes toward and away from the hub axis about a segment of helical path to effect a change in the pitch of each blade. One or more elastic members draw the blades toward the hub axis, either directly or indirectly. There are pitch mechanisms effective to facilitate blades to spiral around housing-longitudinal axes. A blade will spiral away from the hub axis when the centrifugal force exerted on the blade exceeds the opposing elastic force in the housing-longitudinal direction (neglecting other forces). Conversely, blades spiral toward the hub axis when said centrifugal force is less than said elastic force. There is an imaginary plane orthogonal to the hub axis. Housing-longitudinal axes have angles with respect to the imaginary plane of not more than 30 degrees.

Abstract: A pitch control system characterized by a hub with at least two blade housings on the hub that are disposed around the hub axis. The blade housings have corresponding blades that engage with them. The blades spiral along housing longitudinal axes toward and away from the hub axis about a segment of helical path to effect a change in the pitch of each blade. One or more elastic members draw the blades toward the hub axis, either directly or indirectly. There are pitch mechanisms effective to facilitate blades to spiral around housing-longitudinal axes. A blade will spiral away from the hub axis when the centrifugal force exerted on the blade exceeds the opposing elastic force in the housing-longitudinal direction (neglecting other forces). Conversely, blades spiral toward the hub axis when said centrifugal force is less than said elastic force. There is an imaginary plane orthogonal to the hub axis. Housing-longitudinal axes have angles with respect to the imaginary plane of not more than 30 degrees.

Abstract: An unmanned aircraft capable of vertical takeoff, vertical landing, and/or flight in a hovering orientation is presented; its fixed-wing is positively-swept and of low aspect-ratio with suitable airfoils. The unmanned aircraft includes a thruster comprising two contra-rotating motors and propellers forward of the fixed-wing's leading-edge and a rudderless fin aft of the center-of-mass, all of which lie on the aircraft's plane-of-symmetry. Two elevons provide pitch and roll control. The unmanned aircraft can stand upright on its feet. A control system for aircraft with at least one wing is also presented. The control system includes a mount and attached thruster which lie on the plane-of-symmetry forward of the fixed-wing's leading-edge. A hinge axis approximately perpendicular to the aircraft's horizontal plane passes through the mount. The thruster rotates about the hinge axis for aircraft yaw control.