A rotor hub for a reaction drive type helicopter includes a cylindrical sidewall having a top and an open bottom which defines an interior volume. A top plate closes the top of the cylindrical sidewall, and at least two pipe sections extend outwardly from the cylindrical sidewall. Each pipe section extends through the sidewall in communication with the interior volume. A horizontal vane is carried in an inlet of the pipe section and extends horizontally across the inlet. A three dimensional body extends downwardly from a central axis of the top plate into the interior volume.

A compressed gas ejection assembly 10 for a rotating wing aircraft blade 2 comprises a compressed gas passage 114 adapted to allow a substantially constant mass flow through the compressed gas ejection assembly 10 across at least a portion of the width of the compressed gas ejection assembly 10.

A directional control system for a rotorcraft having a tail boom including a no-tail-rotor apparatus configured to control rotorcraft yaw using forced air ejected from the tail boom and a duct configured to deliver the forced air to the no-tail-rotor apparatus. The directional control system comprises a heat exchanger having air passages and fluid passages, the air passages in fluid communication with the duct, the fluid passages in heat exchange relationship with the air passages and configured for receiving a cooling fluid, and a forced air driver in fluid communication with the duct for driving the forced air through the duct to the no-tail-rotor apparatus. Methods of providing directional control in a rotorcraft are also discussed.

Tail boom drive systems for helicopters are described which utilize a fan internal to the tail boom to provide yaw control, and an external propulsor to provide forward thrust. In one embodiment, the tail boom drive system includes a shaft, a fan, and a propulsor. The shaft is disposed lengthwise within an interior space of the tail boom, and the shaft has a first end and a second end. The fan is mechanically coupled coaxially to the shaft within the interior space between the first end and the second end, and the fan generates a variable airflow directed towards the second end that is ejected from the interior space substantially perpendicular to the tail boom. The propulsor is external to the tail boom and is mechanically coupled coaxially to the shaft at the second end, and the propulsor generates a variable thrust directed towards the first end.

The present disclosure is directed to a method for controlling rotors of a rotorcraft system comprising the steps of: receiving air velocity data, first and second rotors rotational angular velocity data, external air temperature data and rotorcraft altitude data by the control module; calculating air velocity over the plurality of blades based on the received data using the control module; calculating, based on the calculated air velocity, if one or more retreating blades of one of the first and second counterrotating rotors are generating insufficient lift; and sending one or more actuation signals from the control module to the electric motor and/or actuators of the other of the first and second counterrotating rotors to maintain a predetermined amount of lift.

There is disclosed a cooling system for a liquid cooled internal combustion power plant housed in an engine compartment in a tail cone of an aircraft. The cooling system has: a tail cone inlet defined through a wall of the tail cone and fluidly communicating with an environment; a wall inlet defined through a firewall of the engine compartment; a blower within the engine compartment and having a blower inlet and a blower outlet, the blower inlet fluidly communicating with the environment via the tail cone inlet, via the wall inlet, and via an interior of the engine compartment; a blower outlet defined through a wall of the aircraft and fluidly communicating with the environment; and a cooling flow path extending from the tail cone inlet to the air outlet and across the wall inlet, the cooling flow path in heat exchange relationship with the power plant.

There is disclosed a cooling system for a liquid cooled internal combustion aircraft power plant for an aircraft having a tail cone. The cooling system has: an air inlet defined through a wall of the tail cone and fluidly connected to an environment outside the aircraft; a heat exchanger having at least one first conduit fluidly connected to the environment via the air inlet and at least one second conduit in heat exchange relationship with the at least one first conduit and fluidly connectable to a coolant circuitry of the liquid cooled internal combustion aircraft power plant; a blower fluidly connected to the environment via the air inlet; and an air outlet fluidly connected to the blower and defined through a wall of the aircraft upstream of the air inlet relative to a direction of an airflow along the aircraft.

There is disclosed a cooling system for a liquid cooled internal combustion aircraft power plant for an aircraft having a tail cone. The cooling system has: an air inlet defined through a wall of the tail cone and fluidly connected to an environment outside the aircraft; a heat exchanger having at least one first conduit fluidly connected to the environment via the air inlet and at least one second conduit in heat exchange relationship with the at least one first conduit and fluidly connectable to a coolant circuitry of the liquid cooled internal combustion aircraft power plant; a blower fluidly connected to the environment via the air inlet; and an air outlet fluidly connected to the blower and defined through a wall of the aircraft upstream of the air inlet relative to a direction of an airflow along the aircraft.

There is disclosed a cooling system for a liquid cooled internal combustion power plant housed in an engine compartment in a tail cone of an aircraft. The cooling system has: a tail cone inlet defined through a wall of the tail cone and fluidly communicating with an environment; a wall inlet defined through a firewall of the engine compartment; a blower within the engine compartment and having a blower inlet and a blower outlet, the blower inlet fluidly communicating with the environment via the tail cone inlet, via the wall inlet, and via an interior of the engine compartment; a blower outlet defined through a wall of the aircraft and fluidly communicating with the environment; and a cooling flow path extending from the tail cone inlet to the air outlet and across the wall inlet, the cooling flow path in heat exchange relationship with the power plant.

An aircraft engine assembly having a turbo-compounded internal combustion engine having an engine shaft. A coolant cooler is fluidly connected to a coolant circuitry of the internal combustion engine and to the environment. A plenum is connected with the environment via the coolant cooler and via an air outlet. A fan is disposed adjacent the air outlet and is operable to drive an airflow from the environment into the plenum via the coolant cooler. The fan is spaced apart from the internal combustion engine in a direction perpendicular to the engine shaft. A method of defining a cooling air circulation is also discussed.