A new invention in the field of helicopter construction has been registered in Russia, which allows controlling a helicopter in yaw without a classic tail rotor. The patent describes a jet system for compensating the reactive torque of the main rotor with a separate electric drive.
The developers have come up with a system that sucks air directly from the atmosphere through air intakes located on the fuselage under the main rotor.
The flow through the air duct enters a two-stage compressor, which is driven by an electric motor installed in the tail section of the fuselage. Then, the compressed air is directed into the tail duct and ejected through controlled nozzles.
The key feature of the development is the complete preservation of the power of the main engine and main rotor. The compressor and nozzles are powered by a separate electric motor, and not by a gearbox, as in traditional NOTAR schemes. This reduces the load on the power plant and increases reliability during takeoff, landing, and hovering.
The distribution of air flow between the nozzles varies depending on the flight mode. In cruise mode, the ratio is 0.7 to 0.3, and when performing a turn, it is 0.55 to 0.45, which ensures controlled yaw without sharp angular accelerations.
This is not the first unusual domestic development in the field of helicopter construction. It recently became known that the Russian Federation has patented a helicopter design with a turbine-driven main rotor.
