Abstract: An aircraft is provided and includes a rotor, which is rotatable relative to an airframe, a rotor, which is rotatable relative to the airframe and which generates a rotor induced vibration, an engine to generate rotational energy, a drive portion to transfer the rotational energy from the engine, a gearbox disposed to transmit the rotational energy from the drive portion to the rotor to drive rotor rotation, support members connecting the gearbox to the airframe and an actuation system configured to generate an anti-vibration load applicable to the gearbox via an actuator comprising an actuator element disposed along one of the support members and a stinger element extending from the actuator element to a connection point of the support member and the gearbox to transmit a portion of the anti-vibration load from the actuator element to the connection point to counter the rotor induced vibration at the gearbox.

Abstract: An aircraft is provided and includes an airframe, an engine, a drive portion driven by the engine, a rotor apparatus, which includes a rotor rotatable relative to the airframe and a fairing, a gearbox disposed to transmit rotational energy from the drive portion to the rotor to drive the rotor to rotate relative to the airframe and which generates a rotor rotation vibration, support members by which the gearbox is disposed on the airframe and an actuation system including actuation elements disposed at the fairing, the actuation system being configured to generate an anti-vibration moment using the actuation elements disposed at the fairing to counter the rotor rotation vibration.

Abstract: An aircraft includes an airframe; an extending tail; a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly; a translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe; an upper hub fairing positioned at the upper rotor assembly; a lower hub fairing positioned at the lower rotor assembly; and a shaft fairing disposed between the upper hub fairing and the lower hub fairing; wherein the upper hub fairing is substantially sealed to the shaft fairing and the lower hub fairing is substantially sealed to the shaft fairing.

Abstract: An aircraft is provided and includes an airframe, an engine, a drive portion driven by the engine, a rotor apparatus, which includes a rotor rotatable relative to the airframe and a fairing, a gearbox disposed to transmit rotational energy from the drive portion to the rotor to drive the rotor to rotate relative to the airframe and which generates a rotor rotation vibration, support members by which the gearbox is disposed on the airframe and an actuation system including actuation elements disposed at the fairing, the actuation system being configured to generate an anti-vibration moment using the actuation elements disposed at the fairing to counter the rotor rotation vibration.

Abstract: An aircraft is provided and includes a rotor, which is rotatable relative to an airframe, a rotor, which is rotatable relative to the airframe and which generates a rotor induced vibration, an engine to generate rotational energy, a drive portion to transfer the rotational energy from the engine, a gearbox disposed to transmit the rotational energy from the drive portion to the rotor to drive rotor rotation, support members connecting the gearbox to the airframe and an actuation system configured to generate an anti-vibration load applicable to the gearbox via an actuator comprising an actuator element disposed along one of the support members and a stinger element extending from the actuator element to a connection point of the support member and the gearbox to transmit a portion of the anti-vibration load from the actuator element to the connection point to counter the rotor induced vibration at the gearbox.