Helicopter with reduced blade vortex interaction noise

摘要

A helicopter main rotor has control devices/actuator (16) to control different setting angle courses (SAC) selectively on adjacent rotor blades (ARB) during a flight so that the blade tips of ARB describe different circuits during a rotation. Groups (2A/B,2C/D) of ARB fitted uniformly on the periphery of a rotor hub form the rotor. ARB in each group have the same SAC in a quasi-static condition.