Patent ID: 7451949

Claim:
A method of reducing vibration in a structure of a helicopter having a main rotor and a tail boom with a substantially horizontal stabilizer and a tail rotor, comprising the steps of: exciting a vertical vibration in the tail boom of the helicopter with a downward flow of air from the main rotor onto the structure of the helicopter, the downward flow of air having a diameter substantially equal to a diameter of the main rotor and having varying pressure and speed; measuring the vertical vibration on at least one location of the helicopter; determining a variation of an angle of incidence of a movable control surface of the substantially horizontal stabilizer that generates a force opposing the measured vertical vibration; and varying the angle of incidence of the movable control surface of the substantially horizontal stabilizer the determined variation to generate the force opposing the measured vertical vibration without applying alternating variation to a pitch of blades of the tail rotor.