Abstract: A mechanism for transitioning a tiltrotor aircraft between rotary and non rotary flight modes. The mechanism includes a gimbal lock positioned about a mast that is operable to selectively enable and disable a gimballing degree of freedom of a rotor assembly relative to the mast. A blade stop assembly, positioned about the mast, includes a plurality of arms having a radially contracted orientation and a radially extended orientation. A blade lock assembly is operably associated with each rotor blade assembly. Each blade lock assembly is operable to selectively enable and disable a folding degree of freedom and a pitching degree of freedom of the respective rotor blade assembly. A swash plate is operable to change the pitch of the rotor blade assemblies in the rotary flight mode and fold the rotor blade assemblies in the non rotary flight mode.

Abstract: An aircraft comprises a fuselage, one or more support structures connected to the fuselage, one or more engines or motors disposed within or attached to the one or more support structures or the fuselage, and a distributed propulsion system. The distributed propulsion system comprising two or more propellers symmetrically distributed in an array along the one or more support structures with respect to a center of gravity of the aircraft and operably connected to the one or more engines or motors, wherein each propeller has a rotation direction within a tilted plane of rotation, and a summation of horizontal force vectors created by the tilted plane of rotation of all the propellers is substantially zero when all the propellers are creating a substantially equal thrust magnitude. Movement of the aircraft is controlled by selectively increasing or decreasing a thrust of at least one of the two or more propellers.

Abstract: A propulsion system for a rotorcraft includes a first fan assembly including a plurality of first fan blades, a second fan assembly including a plurality of second fan blades and a drive system adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the drive system, thereby providing responsive thrust control for the rotorcraft.

Abstract: The present invention includes an anti-torque assembly for a helicopter comprising a plurality of fixed blade pitch motors mounted on one or more pivots on the tail boom of the helicopter, wherein the plurality of fixed blade pitch motors on the one or more pivots are adapted to be oriented substantially in-plane with a tail boom of a helicopter during a first mode of operation that comprises a hover mode and wherein the fixed blade pitch motors are adapted to be oriented substantially off-plane from the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode.

Abstract: Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body, and multiple motor assemblies coupled to the primary spool that provide selective displacement of the primary spool or the secondary spool. Each motor assembly includes a clutching mechanism that selectively couples a motor of the motor assembly to and from the primary spool.

Abstract: A tail sitter aircraft includes a fuselage having a forward portion, an aft portion and a longitudinally extending fuselage axis. At least two wings are supported by the forward portion of the fuselage. A distributed propulsion system includes at least one propulsion assembly operably associated with each fixed wing and is operable to provide forward thrust during forward flight and vertical thrust during vertical takeoff, hover and vertical landing. A tailboom assembly extends from the aft portion of the fuselage and includes a plurality of rotatably mounted tail arms having control surfaces and landing members. In a forward flight configuration, the tail arms are radially retracted to reduce tail surface geometry and provide yaw and pitch control with the control surfaces. In a landing configuration, the tail arms are radially extended relative to the fuselage axis to form a stable ground contact base with the landing members.

Abstract: A tail sitter aircraft includes a fuselage having a forward portion, an aft portion and a longitudinally extending fuselage axis. A main lifting surface is supported by the forward portion of the fuselage. A propulsion system is operably associated with the main lifting surface and operable to provide thrust during forward flight, vertical takeoff, hover and vertical landing. A tailboom assembly extends from the aft portion of the fuselage. The tailboom assembly includes a plurality of rotatably mounted tail arms having control surfaces and landing members wherein, in a forward flight configuration, the tail arms are radially retracted to reduce tail surface geometry and provide yaw and pitch control with the control surfaces and, wherein, in a landing configuration, the tail arms are radially extended relative to one another about the fuselage axis to form a stable ground contact base with the landing members.

Abstract: The present invention includes an anti-torque assembly for a helicopter comprising a plurality of fixed blade pitch motors mounted on one or more pivots on the tail boom of the helicopter, wherein the plurality of fixed blade pitch motors on the one or more pivots are adapted to be oriented substantially in-plane with a tail boom of a helicopter during a first mode of operation that comprises a hover mode and wherein the fixed blade pitch motors are adapted to be oriented substantially off-plane from the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode.

Abstract: Embodiments refer generally to systems and methods for providing autorotative enhancement for helicopters using an autorotative assist unit coupled to the transmission of the helicopter. Methods of utilizing an autorotative assist unit as well as retrofitting an autorotative assist unit to an existing helicopter are also disclosed. By employing an autorotative assist unit, improved autorotation can be achieved without the need to increase the weight of the rotor.

Abstract: A hydraulic system for an aircraft having an engine and an auxiliary power unit includes a first hydraulic subsystem including a first hydraulic pump and a first set of hydraulic-powered components in fluid communication with the first hydraulic pump. The first hydraulic pump is powered by the engine to pump shared hydraulic fluid to the first set of hydraulic-powered components. The hydraulic system includes a second hydraulic subsystem including a second hydraulic pump and a second set of hydraulic-powered components in fluid communication with the second hydraulic pump. The second hydraulic pump is powered by the auxiliary power unit to pump the shared hydraulic fluid to the second set of hydraulic-powered components. A shared return line subsystem and reservoir is in fluid communication with the first and second hydraulic subsystems to return the shared hydraulic fluid to the first and second hydraulic pumps.

Abstract: Embodiments refer generally to systems and methods for providing autorotative enhancement for helicopters using an autorotative assist unit coupled to the transmission of the helicopter. Methods of utilizing an autorotative assist unit as well as retrofitting an autorotative assist unit to an existing helicopter are also disclosed. By employing an autorotative assist unit, improved autorotation can be achieved without the need to increase the weight of the rotor.

Abstract: The present invention includes a hybrid propulsion system for an aircraft comprising: one or more turboshaft engines that provide shaft power and are capable of providing thrust; at least one of: one or more electrical generators or one or more hydraulic pumps connected to a shaft of the one or more turboshaft engines; and at least two rotatable nacelles, each nacelle housing at least one of: one or more electric motors or one or more hydraulic motors each connected to a proprotor, wherein the electric motor is electrically connected to the electric generator, or the hydraulic motor is connected to the hydraulic pump, respectively, wherein the proprotors provide lift whenever the aircraft is in vertical takeoff and landing and stationary flight, and provide thrust whenever the aircraft is in forward flight.

Abstract: An aircraft capable of vertical takeoff and landing, stationary flight and forward flight includes a closed wing that provides lift whenever the aircraft is in forward flight, a fuselage at least partially disposed within a perimeter of the closed wing, and one or more spokes coupling the closed wing to the fuselage. One or more engines or motors are disposed within or attached to the closed wing, fuselage or spokes. Three or more propellers are proximate to a leading edge of the closed wing or the one or more spokes, distributed along the closed wing or the one or more spokes, and operably connected to the one or more engines or motors. The propellers provide lift whenever the aircraft is in vertical takeoff and landing and stationary flight, and provide thrust whenever the aircraft is in forward flight.

Abstract: An aircraft includes a closed wing, a fuselage at least partially disposed within a perimeter of the closed wing, and one or more spokes coupling the closed wing to the fuselage. A plurality of hydraulic or electric motors are disposed within or attached to the closed wing, fuselage or spokes in a distributed configuration. A propeller is proximate to a leading edge of the closed wing or spokes and operably connected to each hydraulic or electric motor. A source of hydraulic or electric power is disposed within or attached to the closed wing, fuselage or spokes and coupled to each hydraulic or electric motor disposed within or attached to the closed wing, fuselage or spokes. A controller is coupled to each hydraulic or electric motor, and one or more processors communicably coupled to each controller that control an operation and speed of the plurality of hydraulic or electric motors.

Abstract: An aircraft capable of vertical takeoff and landing and stationary flight includes a distributed airframe coupled to a modular fuselage. The modular fuselage has a longitudinal axis substantially parallel to a rotational axis of three or more propellers. The modular fuselage includes a rear module substantially disposed within a perimeter of the distributed airframe, a front module removably connected to the rear module and substantially aligned with the longitudinal axis. One or more engines or motors are disposed within or attached to the distributed airframe or fuselage. The three or more propellers are proximate to a leading edge of the distributed airframe, distributed along the distributed airframe, and operably connected to the one or more engines or motors to provide lift whenever the aircraft is in vertical takeoff and landing and stationary flight.

Abstract: The present invention includes a distributed propulsion system for a craft that comprises a frame, a plurality of hydraulic or electric motors disposed within or attached to the frame in a distributed configuration; a propeller operably connected to each of the hydraulic or electric motors, a source of hydraulic or electric power disposed within or attached to the frame and coupled to each of the disposed within or attached to the frame, wherein the source of hydraulic or electric power provides sufficient energy density for the craft to attain and maintain operations of the craft, a controller coupled to each of the hydraulic or electric motors, and one or more processors communicably coupled to each controller that control an operation and speed of the plurality of hydraulic or electric motors.

Abstract: A rotor blade rotation system includes two or more rotor blades, each rotor blade in mechanical communication with a hub and pivotable about an axis of rotation, a bearing plate comprising a rotating portion and a non-rotating portion, a fold linkage coupled to the rotating portion of the bearing plate and in mechanical communication with the rotor blade, and an actuator coupled to the non-rotating portion of the bearing plate and operable to reposition the bearing plate from a first position to a second position such that the folding links pivot the rotor blades from a deployed position to a forward folded position.

Abstract: A tail sitter aircraft includes a fuselage having a forward portion, an aft portion and a longitudinally extending fuselage axis. A main lifting surface is supported by the forward portion of the fuselage. A propulsion system is operably associated with the main lifting surface and operable to provide thrust during forward flight, vertical takeoff, hover and vertical landing. A tailboom assembly extends from the aft portion of the fuselage. The tailboom assembly includes a plurality of rotatably mounted tail arms having control surfaces and landing members wherein, in a forward flight configuration, the tail arms are radially retracted to reduce tail surface geometry and provide yaw and pitch control with the control surfaces and, wherein, in a landing configuration, the tail arms are radially extended relative to one another about the fuselage axis to form a stable ground contact base with the landing members.

Abstract: The present invention includes an anti-torque assembly for a helicopter comprising a plurality of fixed blade pitch motors mounted on one or more pivots on the tail boom of the helicopter, wherein the plurality of fixed blade pitch motors on the one or more pivots are adapted to be oriented substantially in-plane with a tail boom of a helicopter during a first mode of operation that comprises a hover mode and wherein the fixed blade pitch motors are adapted to be oriented substantially off-plane from the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode.