Abstract: A drive system for a rotorcraft includes at least one engine, the engine including a compressor section, and a turbine section positioned rearward from the compressor section. A main rotor input shaft extends from a rotor power turbine of the turbine section and is connectable to a main rotor assembly of the rotorcraft to transfer rotational energy from the rotor power turbine to the main rotor assembly. An auxiliary input shaft extends from an auxiliary power turbine of the turbine section and is connectible to an auxiliary rotor assembly of the rotorcraft to transfer rotational energy from the auxiliary power turbine to the auxiliary rotor assembly.

Abstract: A retractable landing gear system for a vertical takeoff and landing (VTOL) aircraft includes a rotational strut rotatably coupled to a fuselage of the VTOL aircraft. The rotational strut includes a first end, a second end, and an intermediate portion extending therebetween. A drag strut includes a first end portion pivotally connected to the rotational strut and a second end portion. A locking link includes a first end section pivotally connected relative to the fuselage, a second end section pivotally connected to the drag strut and an intermediate section having a hinge element. A retraction system is operatively connected to the rotational strut and the locking link. The retraction system is operable to pivot the drag strut about a first axis and rotate the rotational strut about a second axis that is distinct from the first axis.

Abstract: A rotor system of a tail-sitter aerial vehicle configured to rotate about an axis of rotation is provided including a rotor hub which rotates about the axis of rotation and at least one rotor blade operably coupled to the rotor hub. The at least one rotor blade is configured to rotate about a folding axis between an extended position where the at least one rotor blade is substantially within a plane perpendicular to the axis of rotation and a stowed position where the rotor blade is arranged out of the plane of at an angle less than ninety degrees to the axis of rotation.

Abstract: An adjustable cable attachment system for a VTOL aircraft includes a VTOL airframe. A winch is operatively connected to an underside of the airframe with the aircraft in a horizontal flight mode. An adjustable cable is operatively connected to the winch to adjustably relocate a slung load with respect to the center of gravity of the aircraft to balance the aircraft. A fixed cable is operatively connected to the underside of the airframe with the aircraft in the horizontal flight mode.

Abstract: A propeller blade is provided including a leading edge and a trailing edge. The trailing edge is arranged opposite the leading edge to form an airfoil there between. At least one of the leading edge and the trailing edge include at least one facet.

Abstract: An aircraft includes a fuselage and a wing extending from each lateral side of the fuselage. A nacelle is pivotably se cured to each wing. The nacelle has a rotor located thereat, with the rotor having a rotor tip path plane defined by rotation of the rotor about a rotor axis of rotation. When the rotor tip path plane is changed relative to the wing, the nacelle pivots relative to the wing about a nacelle hinge axis to reduce flapping required by the rotor. A method of operating an aircraft includes changing a rotor tip path plane orientation relative to a wing of the aircraft. The rotor disposed at a nacelle, with the nacelle pivotably secured to the wing. The nacelle is pivoted relative to the wing to reduce an overall tip path plane change requirement of the rotor.

Abstract: A vertical take-off and landing (VTOL) aircraft is provided and includes wings, first and second nacelles supported on each of the wings, each of the first and second nacelles including a propeller drivable to generate aircraft thrust, and an asymmetrical power generation unit. The asymmetrical power generation unit includes a single engine unit disposed in only one of the first and second nacelles to generate power to drive the propellers of both the first and second nacelles.

Abstract: An aircraft is provided and includes a fuselage from which a tilt-wing respectively extends, first prop-rotors, which are formed to define first rotor disks and which are respectively disposed on first portions of each side of the tilt-wing, second prop-rotors, which are formed to define second rotor disks and which are respectively disposed on second portions of each side of the tilt-wing such that the corresponding pairs of first and second rotor disks overlap, and a drive shaft system. The drive shaft system is configured to synchronize respective operations of the first and second prop-rotors.

Abstract: A vertical take-off and landing (VTOL) aircraft is provided. The aircraft includes a wing, nacelles supportively disposed at opposite ends of the wing, proprotors respectively attached to each of the nacelles with each of the proprotors being rotatable to generate lift in vertical flight and thrust in horizontal flight and a delta-wing shaped fuselage disposed along the wing between the nacelles.

Abstract: A yaw control system of an aircraft includes an aircraft having an airframe extending along a longitudinal axis, a coaxial contra-rotating main rotor system rotatable about a first axis, and a rotor system rotatable about a second axis to move air between a first side of the airframe and a second, opposite side of the airframe. The first side and the second side are disposed on opposing sides of the longitudinal axis. The yaw control provided by operation of the rotor system is supplemental to the yaw control provided by the coaxial contra-rotating main rotor system.

Abstract: An aircraft includes an airframe having an extending tail and a longitudinal axis extending from a nose of the airframe defining a length of the airframe. A counter rotating, coaxial main rotor assembly is located at the airframe and includes an upper rotor assembly and a lower rotor assembly. The upper rotor assembly and the lower rotor assembly rotate about an axis of rotation. The axis of rotation intersects the longitudinal axis forward of a midpoint of the longitudinal axis.

Abstract: An aircraft includes a fuselage defining an aircraft attitude axis. The fuselage houses an engine fixed relative to the aircraft attitude axis. A rotor assembly is operatively connected to rotate back and forth relative to the aircraft attitude axis from a first position predominately for lift to a second position predominately for thrust. The rotor assembly includes a rotor that is operatively connected to be driven by the engine.

Abstract: A flight control system for an aircraft includes a flight control computer operatively interconnected with a main rotor system and a translational thrust system of the aircraft. A selectively enabled integrated target and flight control system arranged in communication with the flight control computer. The integrated target flight and control system is configured to control pitch attitude and heading of the aircraft. When the integrated target and flight control system is enabled, at least partial operation of the aircraft is controlled in response to a pilot input via the flight control computer.

Abstract: A tiltwing aircraft includes a fuselage, an engine mounted stationary relative to the fuselage, and an opposed pair of wings. The wings are separated from each other with the fuselage therebetween, each wing independently mounted to the fuselage by a respective pivot system for rotation relative to the fuselage. An opposed pair of rotor assemblies is included, each operatively connected to a respective one of the wings for common rotation with the respective wing back and forth between a first position predominantly for lift to a second position predominantly for thrust.

Abstract: A cooling system for a rotorcraft laser system is provided. The cooling system includes at least one laser carrying component operatively coupling a laser turret and a laser generating assembly. The cooling system also includes at least one fuel line fluidly coupled to a fuel tank containing a fuel. The cooling system further includes a heat exchanger containing a portion of the laser carrying component and the fuel line to transfer heat therebetween to cool the laser carrying component.

Abstract: A vertical take-off and landing (VTOL) aircraft is provided and includes a fuselage, wings extending outwardly from opposite sides of the fuselage, nacelles supportively disposed on the wings and reversely oriented, axial flow engines disposed in each of the nacelles to generate mechanical energy for driving lift and thrust generating prop-rotor rotations.

Abstract: A method for determining a center-of-gravity of an aircraft in three dimensions includes determining a first center-of-gravity location for an aircraft in a first plane defined by a first axis and a second axis. The method includes positioning the aircraft in a tilted position by rotating the aircraft and determining a second center-of-gravity location for the aircraft in the first plane in the tilted position. The method includes comparing the first center-of-gravity location to the second center-of-gravity location to determine a component of the first center-of-gravity location along a third axis defined out-of-plane from the first plane to determine a three-dimensional center-of-gravity of the aircraft.

Abstract: A retractable landing gear system for a vertical takeoff and landing (VTOL) aircraft includes a rotational strut rotatably coupled to a fuselage of the VTOL aircraft. The rotational strut includes a first end, a second end, and an intermediate portion extending therebetween. A drag strut includes a first end portion pivotally connected to the rotational strut and a second end portion. A locking link includes a first end section pivotally connected relative to the fuselage, a second end section pivotally connected to the drag strut and an intermediate section having a hinge element. A retraction system is operatively connected to the rotational strut and the locking link. The retraction system is operable to pivot the drag strut about a first axis and rotate the rotational strut about a second axis that is distinct from the first axis.

Abstract: A fairing for a landing gear wheel assembly on a tail sitter aircraft is disclosed, which includes a fairing housing defining a longitudinal axis, and at least one pair of laterally opposed aerodynamic tail surfaces extending radially outward from the fairing housing for added flight stability.

Abstract: An aircraft is provided and includes a fuselage, first and second wings extending outwardly from opposite sides of the fuselage, proprotors operably disposed on each of the first and second wings to drive vertical take-off and landing aircraft operations and horizontal flight aircraft operations and a refueling system including at least one fuel tank disposed in at least one or more of the fuselage, the first wing or the second wing and a refueling apparatus. The refueling apparatus is coupled to the at least one fuel tank such that fuel is movable with respect to the at least one fuel tank during aircraft ground and aerial operations.