Abstract: An aircraft includes an airframe, and a coaxial main rotor assembly including a static mast and an upper rotor assembly and a lower rotor assembly rotatable about a main rotor axis defined by the static mast. The upper rotor assembly and the lower rotor assembly are independently rotatable about the static mast. A propulsion system includes at least one propulsion source for directly driving at least one of the upper rotor assembly and the lower rotor assembly and a flight control system is operably coupled to the propulsion system. The flight control system is operable to independently control a rotational speed of the upper rotor assembly and the lower rotor assembly relative to the static mast.

Abstract: An aircraft includes an airframe, and a coaxial main rotor assembly including a static mast and an upper rotor assembly and a lower rotor assembly rotatable about a main rotor axis defined by the static mast. The upper rotor assembly and the lower rotor assembly are independently rotatable about the static mast. A propulsion system includes at least one propulsion source for directly driving at least one of the upper rotor assembly and the lower rotor assembly and a flight control system is operably coupled to the propulsion system. The flight control system is operable to independently control a rotational speed of the upper rotor assembly and the lower rotor assembly relative to the static mast.

Abstract: A rotor blade for a rotary aircraft is disclosed. The rotor blade includes a body and an airflow duct extending within the body of the rotor blade. An airflow outlet of the airflow duct is located at a tip of the blade. The airflow outlet has a cross-sectional area that is equal to or greater than a cross-sectional area of the airflow duct. The rotor blade is used to mitigate brownout during flight. Air exits the rotor blade at the airflow outlet in order to disrupt a blade vortex created by rotation of the rotor blade.

Abstract: An inset configured for use in a rotor blade is provided including a body having a shape generally complementary to a hole formed in the rotor blade. An opening extends between a first surface and a second surface of the body. The opening is configured to provide a fluid flow path between an interior and an exterior of the rotor blade.

Abstract: A flying wing vertical take-off and landing (VTOL) aircraft includes an empennageless-fuselage from which foldable wings extend outwardly, an empennageless-nacelle supported on each of the wings and a rigid rotor propeller disposed on each empennageless-nacelle, each of the propellers being drivable to rotate about only a single rotational axis defined along a longitudinal axis of the corresponding empennageless-nacelle and being fully cyclically controllable.

Abstract: A rotary winged aircraft includes an airframe and a drive system located at the airframe. A main rotor system is positioned at the airframe and is operably connected to the drive system to provide lift for the rotary winged aircraft. An auxiliary propulsor is located at the airframe and includes a plurality of propeller blades rotatable about a propulsor axis. Collective and cyclic pitch input applied to the auxiliary propeller blades increases yaw performance of the aircraft. A method of operating a rotary wing aircraft includes powering an auxiliary propulsor secured to an airframe of the aircraft and including a plurality of propeller blades rotatable about a propulsor axis. Individual propeller blades are cyclically rotated about their respective propeller blade axes to cyclically change a propeller blade pitch. Rotation of the aircraft about a yaw axis is induced via the collective and cyclic pitch change of the propeller blades.

Abstract: A closeout structure for a rotor blade includes a first fluid channel for supplying a first pressure to a first port of a trailing edge (TE) device, a second fluid channel for supplying a second pressure to a second port of the TE de vice, and a trough disposed between the first fluid channel and the second fluid channel. The closeout structure forms a double-W shape.

Abstract: A blade includes an elongated body having a leading edge, a trailing edge, a root end, and a tip end, a fluid inlet arranged closer to the root end than the fluid outlet, a fluid outlet arranged near the tip end of the elongated body, and a centrifugal air flow channel defined within the body between the inlet and the outlet to direct air from the inlet to the outlet to issue the flow when the rotor blade is rotating in a rotational path. The blade also includes a valve to selectively open and close the centrifugal air flow channel to selectively issue the flow and change a blade vortex issuing from the rotor blade at discrete portions of the rotational path of the rotor blade. A controller can be operatively connected to the valve to control the valve to open and close the centrifugal air flow channel.

Abstract: A rotor blade includes an elongated body having a leading edge, a trailing edge, a proximal end, and a distal end; a fluid inlet; a fluid outlet arranged near the distal end of the elongated body; and a fluid duct contained within the elongated body, the fluid duct being substantially open between the fluid inlet and the fluid outlet, the fluid duct having a shape to reduce fluid velocities C generated by the interaction of fluid exiting the fluid duct and external fluid at the distal end.

Abstract: A flying wing vertical take-off and landing (VTOL) aircraft is provided and includes an empennageless-fuselage from which foldable wings extend outwardly, an empennageless-nacelle supported on each of the wings and a rigid rotor propeller disposed on each empennageless-nacelle, each of the propellers being drivable to rotate about only a single rotational axis defined along a longitudinal axis of the corresponding empennageless-nacelle and being fully cyclically controllable.

Abstract: A rotary winged aircraft includes an airframe and a drive system located at the airframe. A main rotor system is positioned at the airframe and is operably connected to the drive system to provide lift for the rotary winged aircraft. An auxiliary propulsor is located at the airframe and includes a plurality of propeller blades rotatable about a propulsor axis. Collective and cyclic pitch input applied to the auxiliary propeller blades increases yaw performance of the aircraft. A method of operating a rotary wing aircraft includes powering an auxiliary propulsor secured to an airframe of the aircraft and including a plurality of propeller blades rotatable about a propulsor axis. Individual propeller blades are cyclically rotated about their respective propeller blade axes to cyclically change a propeller blade pitch. Rotation of the aircraft about a yaw axis is induced via the collective and cyclic pitch change of the propeller blades.

Abstract: A system for a tail-sitter aircraft includes a fuselage having one or more propellers, a wing structure coupled to the fuselage, and a drag rudder assembly coupled to the wing structure, the drag rudder assembly including a first planar member that is coupled to a second planar member. The drag rudder assembly is configured to produce a stabilizing force on the wing structure during higher speeds of the aircraft in tandem rotor flight.

Abstract: A rotor blade for a rotary aircraft is disclosed. The rotor blade includes a body and an airflow duct extending within the body of the rotor blade. An airflow outlet of the airflow duct is located at a tip of the blade. The airflow outlet has a cross-sectional area that is equal to or greater than a cross-sectional area of the airflow duct. The rotor blade is used to mitigate brownout during flight. Air exits the rotor blade at the airflow outlet in order to disrupt a blade vortex created by rotation of the rotor blade.

Abstract: A system for a tail-sitter aircraft includes a fuselage having one or more propellers, a wing structure coupled to the fuselage, and a drag rudder assembly coupled to the wing structure, the drag rudder assembly including a first planar member that is coupled to a second planar member. The drag rudder assembly is configured to produce a stabilizing force on the wing structure during higher speeds of the aircraft in tandem rotor flight.

Abstract: A rotor assembly for a rotary wing aircraft includes a plurality of rotor blades operably connected to a rotor shaft. Two or more active adaptive devices are located at one or more rotor blades of the plurality of rotor blades. The one or more active adaptive devices are operably connected to an aircraft flight control system such that, when activated, the one or more active adaptive devices change one or more operational characteristics of the rotor assembly. A method of operating a rotor assembly of a rotary wing aircraft includes rotating a plurality of rotor blades about a rotor shaft. Two or more active adaptive devices located at one or more rotor blades of the plurality of rotor blades are activated and change one or more operational characteristics of the rotor assembly.

Abstract: Embodiments are directed to causing, by a computing device comprising a processor, a rotating tail rotor to operate in a tail rotor mode when an aircraft is operating at a speed less than a rudder control power threshold, receiving, by the computing device, a command that indicates a request to transition the aircraft, determining, by the computing device, that a rudder of the aircraft has control power in an amount greater than a second threshold based on receiving the command, and causing, by the computing device, the rotating tail rotor to operate in a pusher propeller mode based on determining that the rudder has control power in the amount greater than the second threshold.

Abstract: An aircraft includes a fuselage, and a wing extending from each lateral side of the fuselage. A rotor is secured to each wing; 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 rotor axis of rotation, the wing twists in a direction of the rotor tip path plane change to reduce an angle of attack of the wing relative to a rotor wake of the rotor. A method of operating an aircraft includes changing a rotor tip path plane orientation relative to an axis of rotation of the rotor; the rotor secured to a wing of the aircraft. The wing is twisted to reduce an angle of attack of the wing relative to a rotor wake of the rotor.

Abstract: A rotary wing aircraft includes an airfame and an extending tail extending from the airframe. A main rotor assembly is operably connected to the airframe and includes a plurality of rotor blades operably connected to a rotor shaft, and one or more active adaptive devices located at one or more rotor blades of the plurality of rotor blades. The one or more active adaptive devices are operably connected to an aircraft flight control system such that, when activated, the one or more active adaptive devices change one or more operational characteristics of the rotor assembly. A tail rotor is operably connected to the extending tail. The tail rotor is rotatable about a tail rotor axis and the tail rotor axis movable from laterally-extending to rearward-extending.

Abstract: A rotor blade for a rotary wing aircraft includes a component bay located substantially enclosed in the rotor blade and one or more components positioned in the component bay. An airflow is located at the component bay and an airflow outlet is located at the component bay radially outboard of the airflow inlet. The airflow inlet and airflow outlet allow a continuous airflow through the component bay via centrifugal forces of rotation of the rotor blade, the continuous airflow cooling the one or more components disposed at the component bay.

Abstract: Embodiments are directed to causing, by a computing device comprising a processor, a rotating tail rotor to operate in a tail rotor mode when an aircraft is operating at a speed less than a rudder control power threshold, receiving, by the computing device, a command that indicates a request to transition the aircraft, determining, by the computing device, that a rudder of the aircraft has control power in an amount greater than a second threshold based on receiving the command, and causing, by the computing device, the rotating tail rotor to operate in a pusher propeller mode based on determining that the rudder has control power in the amount greater than the second threshold.