A control system for increasing the damping of a resonant mode of a rotor drive train is provided. A control loop (102) is introduced in parallel with the free turbine speed governing control loop (110). The control loop (102) receives a feedback signal fr...

A power turbine speed control system (10) for a helicopter is disclosed which includes a) means for generating a power turbine speed signal (NF) and a power turbine shaft torque signal (QS) from a power turbine and rotor drive train; b) filtering means (40...

A power turbine speed control system for a helicopter is disclosed which includes components for generating a power turbine speed signal based upon a demanded rotor speed, a high-order filter for filtering the power turbine speed signal by effectuating a r...