Abstract: A rotor blade of a rotary wing aircraft includes a core defining a trailing edge of the rotor blade and a skin extending from the trailing edge defining an opening including the core. The skin defines an aerodynamic surface of the rotor blade. The rotor blade additionally includes at least one trim tab assembly including a trim portion extending from the core beyond the trailing edge of the rotor blade and an actuation system including at least one actuator disposed within the core. The actuation system is operable to adjust an angle of the trim portion relative to the rotor blade.

Abstract: According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

Abstract: A rotor blade of a rotary wing aircraft includes a core defining a trailing edge of the rotor blade and a skin extending from the trailing edge defining an opening including the core. The skin defines an aerodynamic surface of the rotor blade. The rotor blade additionally includes at least one trim tab assembly including a trim portion extending from the core beyond the trailing edge of the rotor blade and an actuation system including at least one actuator disposed within the core. The actuation system is operable to adjust an angle of the trim portion relative to the rotor blade.

Abstract: According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

Abstract: According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

Abstract: An aircraft is provided and includes a fuselage including a top and a tail, a main rotor apparatus disposed at the top of the fuselage, which rotates one or more rotors to generate lift, and an active flow control (AFC) system. The AFC system includes plasma actuators configured to generate plasma at a location adjacent to the main rotor apparatus and/or at the tail of the fuselage.

Abstract: A rotor blade deflection sensing system including a rotor blade having a first surface, a second surface, a third surface and a fourth surface. At least two fiber optic sensor arrays are mounted to the rotor blade. At least one of the at least two fiber optic sensor arrays is mounted to one of the first surface, the second surface, the third surface and the fourth surface and another of the at least two fiber optic sensor arrays being mounted to another of the first surface, a second surface, a third surface and a fourth surface. A controller is operatively connected to the at least two fiber optic sensor arrays. The controller determines one or more of a flapwise and an edgewise displacement based on inputs from the at least two fiber optic sensor arrays.

Abstract: A rotary wing aircraft includes a fuselage having a plurality of surfaces, at least one engine mounted in the fuselage, and a rotor assembly including a rotor shaft and plurality of rotor blades operatively connected to the rotor shaft. The rotor assembly includes a plurality of surface portions. A rotor shaft fairing extends between the fuselage and the rotor assembly and about at least a portion of the rotor shaft. The rotor shaft fairing includes an outer surface. A plate member is mounted to and projects proudly of the at least a portion of the rotor shaft fairing. The plate member is configured and disposed to increase an aspect ratio of and reduce induced drag on the rotor shaft fairing as well as reduce rotor hub wake size.

Abstract: A rotary wing aircraft includes a fuselage having a plurality of surfaces. At least one engine is mounted in the fuselage. A rotor assembly includes a rotor shaft a plurality of rotor blades operatively connected to the rotor shaft. The rotor assembly includes a plurality of surface portions. An active air discharge opening extends through one of the plurality of surfaces of the fuselage and one of the plurality of surface portions of the rotor assembly, and an active air generation system is mounted in the fuselage. The active air generation system is configured and disposed to generate and direct a flow of air through the active air discharge opening to disrupt an airstream flowing over the one of the plurality of surfaces of the fuselage and the one of the plurality of surface portions of the rotor assembly.

Abstract: An aircraft is provided and includes a fuselage including a top and a tail, a main rotor apparatus disposed at the top of the fuselage, which rotates one or more rotors to generate lift, and an active flow control (AFC) system. The AFC system includes plasma actuators configured to generate plasma at a location adjacent to the main rotor apparatus and/or at the tail of the fuselage.

Abstract: According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

Abstract: A rotary wing aircraft includes a fuselage having a plurality of surfaces. At least one engine is mounted in the fuselage. A rotor assembly includes a rotor shaft a plurality of rotor blades operatively connected to the rotor shaft. The rotor assembly includes a plurality of surface portions. An active air discharge opening extends through one of the plurality of surfaces of the fuselage and one of the plurality of surface portions of the rotor assembly, and an active air generation system is mounted in the fuselage. The active air generation system is configured and disposed to generate and direct a flow of air through the active air discharge opening to disrupt an airstream flowing over the one of the plurality of surfaces of the fuselage and the one of the plurality of surface portions of the rotor assembly.

Abstract: A rotary wing aircraft includes a fuselage having a plurality of surfaces, at least one engine mounted in the fuselage, and a rotor assembly including a rotor shaft and plurality of rotor blades operatively connected to the rotor shaft. The rotor assembly includes a plurality of surface portions. A rotor shaft fairing extends between the fuselage and the rotor assembly and about at least a portion of the rotor shaft. The rotor shaft fairing includes an outer surface. A plate member is mounted to and projects proudly of the at least a portion of the rotor shaft fairing. The plate member is configured and disposed to increase an aspect ratio of and reduce induced drag on the rotor shaft fairing as well as reduce rotor hub wake size.

Abstract: A boundary layer ingesting (BLI) blade having a span is provided and includes a root section connectable to a hub, a tip section disposable at a distance from the hub and having a pitch and a body extending in a spanwise dimension from the root section to the tip section. The root section has a local pitch from the root section to about a 70% span location, which is less than the pitch at the tip section, to thereby reduce local angles of attack in a boundary layer region defined in and around the root section.

Abstract: A rotary wing aircraft includes a fuselage having a plurality of surfaces, at least one engine mounted in the fuselage, and a rotor assembly including a rotor shaft, and plurality of rotor blades operatively connected to the rotor shaft. The rotor assembly includes a plurality of surface portions. A plurality of vortex generators is mounted relative to at least one of the plurality of surfaces of the fuselage and the plurality of surface portions of the rotor assembly. The plurality of vortex generators operate to disrupt a boundary layer of air flowing over the one of the plurality of surfaces and the plurality of surface portions to reduce drag on the one of the fuselage and the rotor assembly.

Abstract: A rotor hub fairing system for use in a counter-rotating, coaxial rotor system is provided including an upper hub fairing defined about an axis and a lower hub fairing defined about the axis. A shaft fairing is disposed between the upper hub fairing and the lower hub fairing. The geometry of the shaft fairing is configured to encourage a wake adjacent the upper hub fairing to form collectively with a wake adjacent the lower hub fairing.

Abstract: An electromechanical rotary actuator including a housing including first end that extends to a second end through an intermediate portion that defines a longitudinal axis, and an internal cavity. An electric motor is arranged within the internal cavity. The electric motor includes a shaft having first shaft end and a second shaft end. A drive member is arranged within the housing along the longitudinal axis. The drive member includes an input shaft operatively coupled to the first shaft end and an output shaft. An output shaft member is coupled to the output shaft of the drive member. At least one bearing assembly supports one of the output shaft member and the first shaft end, and a preload member is arranged within the housing and configured to apply a compressive axial force to the at least one bearing, the drive member and the electric motor.

Abstract: A gas turbine engine has an inlet duct formed to have a shape with a first ellipse in one half and a second ellipse in a second half. The second half has an upstream most end which is smaller than the first ellipse. The inlet duct has a surface defining the second ellipse which curves away from the first ellipse, such that the second ellipse is larger at an intermediate location. The second ellipse is even larger at a downstream end of the inlet duct leading into a fan.

Abstract: A rotor blade assembly includes a rotor blade including one or more pockets and a housing located on the rotor blade within one or more pockets. The housing is secured to the rotor blade via one or more dovetail joints. A drive mechanism for a control surface of a rotor blade includes an actuator and a rocker operably connected to the actuator. At least one hinge rod is operably connected to the rocker and operably connected to a control surface at a control surface pivot. The drive mechanism translates substantially linear motion of the actuator into rotational motion of the control surface about the control surface pivot.

Abstract: A rotary wing aircraft includes a rotor assembly includes a rotor sensor generating a rotor sensor time domain signal; a rotor transform module converting the rotor sensor time domain signal to a rotor sensor frequency domain signal; and a rotor transceiver for transmitting the rotor sensor frequency domain signal over a transfer medium; an airframe assembly including: an airframe transceiver receiving the rotor sensor frequency domain signal; and an airframe transform module converting the rotor sensor frequency domain signal to the rotor sensor time domain signal. Signals from the airframe assembly may also be converted to the frequency domain prior to transfer over the transfer medium to the rotor assembly.