Tail rotor control system is described for helicopters. A pedal position sensor operable by a pilot yields greater tail rotor RPM relative to the main rotor RPM, giving the pilot increased control over the vehicle. This proves especially useful in certain situations, such as high altitude, where increasing tail rotor speed from main rotor speed can give a pilot increased maneuverability and stability.

A cooling duct configured to introduce air flow to a cooling target device provided in a helicopter body of a helicopter includes a duct body, a front opening, an upper opening, a hinge, and a movable blade. The duct body is mountable below a main rotor of the helicopter to be adjacent to the cooling target device. The front opening is formed on a forward side of the helicopter body in the duct body. The upper opening is formed on an upper side of the helicopter body in the duct body. The hinge is disposed in an upper portion of the duct body and includes a pivot shaft extending in a lateral direction of the helicopter body. The movable blade with an end that is pivotally supported by the hinge is provided to be pivotable about the pivot shaft between a first position and a second position.

A cooling duct configured to introduce air flow to a cooling target device provided in a helicopter body of a helicopter includes a duct body, a front opening, an upper opening, a hinge, and a movable blade. The duct body is mountable below a main rotor of the helicopter to be adjacent to the cooling target device. The front opening is formed on a forward side of the helicopter body in the duct body. The upper opening is formed on an upper side of the helicopter body in the duct body. The hinge is disposed in an upper portion of the duct body and includes a pivot shaft extending in a lateral direction of the helicopter body. The movable blade with an end that is pivotally supported by the hinge is provided to be pivotable about the pivot shaft between a first position and a second position.

There is provided a system and a method for operating a multi-engine rotorcraft. When the rotorcraft is cruising in an asymmetric operating regime (AOR) at least one engine is an active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft, at least one of a power level of the at least one second engine is increased and at least one variable geometry mechanism of the at least one second engine is moved to shed any ice accumulation on the at least one second engine.

A rotorcraft has a drive system including a main rotor coupled to a main rotor gearbox to rotate the main rotor at a rotor speed, a main engine coupled to the drive system to provide a first power, a supplemental engine coupled, when a first clutch is engaged, to the drive system to provide a second power additive to the first power, and a control system operable to control the main engine and the supplemental engine to provide a total power demand, where the main engine is controlled based on variations in rotor speed and a power compensation command to produce the first power, and the supplemental engine is controlled to produce the second power in response to a supplemental power demand.

A hydroelastic damper comprising at least a first resilient assembly that is provided with a first inner strength member engaged at least in part in a first outer strength member, a first resilient member providing resilient return for the first outer strength member and the first inner strength member towards a rest position (POSREP). The hydroelastic damper comprises at least one hydraulic assembly provided with a first hydraulic chamber and a second hydraulic chamber in communication with each other via a connection provided in a first wall of the hydraulic assembly. A first floating piston is movable at least in translation along the longitudinal axis relative to the first inner strength member and to the first outer strength member, the first hydraulic chamber being defined at least by the first floating piston and the first wall in order to protect the first resilient member.

A hydroelastic damper comprising at least a first resilient assembly that is provided with a first inner strength member engaged at least in part in a first outer strength member, a first resilient member providing resilient return for the first outer strength member and the first inner strength member towards a rest position (POSREP). The hydroelastic damper comprises at least one hydraulic assembly provided with a first hydraulic chamber and a second hydraulic chamber in communication with each other via a connection provided in a first wall of the hydraulic assembly. A first floating piston is movable at least in translation along the longitudinal axis relative to the first inner strength member and to the first outer strength member, the first hydraulic chamber being defined at least by the first floating piston and the first wall in order to protect the first resilient member.

A fully compounding rotorcraft includes a fuselage having first and second wings extending therefrom and configured to provide lift compounding responsive to forward airspeed. A twin boom includes first and second tail boom members that extend aftward from the first and second wings. An empennage is coupled between the aft ends of the tail boom members. An anti-torque system includes a tail rotor that is rotatably coupled to the empennage. An engine is disposed within the fuselage and is configured to provide torque to a main rotor assembly via an output shaft and a main rotor gearbox. An auxiliary propulsive system is coupled to the fuselage and is configured to generate a propulsive thrust to offload at least a portion of a thrust requirement from the main rotor during forward flight, thereby providing propulsion compounding to increase the forward airspeed of the rotorcraft.

A fully compounding rotorcraft includes a fuselage having first and second wings extending therefrom and configured to provide lift compounding responsive to forward airspeed. A twin boom includes first and second tail boom members that extend aftward from the first and second wings. An empennage is coupled between the aft ends of the tail boom members. An anti-torque system includes a tail rotor that is rotatably coupled to the empennage. An engine is disposed within the fuselage and is configured to provide torque to a main rotor assembly via an output shaft and a main rotor gearbox. An auxiliary propulsive system is coupled to the fuselage and is configured to generate a propulsive thrust to offload at least a portion of a thrust requirement from the main rotor during forward flight, thereby providing propulsion compounding to increase the forward airspeed of the rotorcraft.

A driving control device for a remote controlled helicopter includes an rpm detection unit that detects an rpm of a main rotor, a gyro sensor that detects angular velocities of control axes including roll, pitch and yaw axes, and a control unit that generates a control signal of a control actuator for controlling movements of the control axes based on the angular velocities detected by the gyro sensor and a steering signal sent from a transmitter. The control unit has information on the gyro sensitivities of the control axes and information on a set rpm of the main rotor which are preset for each of the flight states of the remote controlled helicopter, and corrects the gyro sensitivities based on a difference between the set rpm corresponding to a selected flight state among the flight states and an rpm of the main rotor detected by the rpm detection unit.