Abstract: 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 rapid attenuation of main and tail rotor torsional frequencies in the power turbine speed signal without compromising phase at low frequencies, and a governor for providing isochronous power turbine speed and rotor speed control based upon the filtered power turbine speed signal.

Abstract: A system is disclosed for determining the total torque required at the main and tail rotors of a helicopter for use in feed-forward rotor torque anticipation which includes a polynomial neural network adapted and configured to predict the aerodynamic torque at the main and tail rotors with the helicopter in motion based upon a plurality of pilot inputs and airframe inputs, a main rotor load map for determining the torque at the main rotor in hover out of ground effects based upon main rotor speed and collective stick position, a tail rotor load map for determining the torque at the tail rotor with the helicopter stationary based upon main rotor speed and pedal position, and a processor for calculating the required total torque at the main and tail rotors by summing the outputs of the polynomial neural network, and the main and tail rotor load maps.

Abstract: The subject invention is directed to a new and useful method of detecting in-range engine sensor faults for a gas turbine engine associated with a helicopter. The method includes the steps of computing engine shaft horsepower for a plurality of engine sensor, computing a first mean horsepower from the plurality of engine sensors, computing the horsepower deviation from the first mean horsepower for each engine sensor, computing a horsepower deviation ratio for each engine sensor relative to all other engine sensors, disabling the engine sensor with the largest deviation from the first mean horsepower, computing a second mean horsepower, computing the horsepower deviation from the second mean horsepower for each engine sensor, re-computing the horsepower deviation ratio for each engine sensor relative to all other engine sensors, comparing the horsepower deviation ratios to predefined limits, and declaring a sensor fault if the horsepower deviation ratio for an engine sensor exceeds a predefined limit.

Abstract: 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 rapid attenuation of main and tail rotor torsional frequencies in the power turbine speed signal without compromising phase at low frequencies, and a governor for providing isochronous power turbine speed and rotor speed control based upon the filtered power turbine speed signal.

Abstract: The subject invention is directed to a new and useful method of detecting in-range engine sensor faults for a gas turbine engine associated with a helicopter. The method includes the steps of computing engine shaft horsepower for a plurality of engine sensor, computing a first mean horsepower from the plurality of engine sensors, computing the horsepower deviation from the first mean horsepower for each engine sensor, computing a horsepower deviation ratio for each engine sensor relative to all other engine sensors, disabling the engine sensor with the largest deviation from the first mean horsepower, computing a second mean horsepower, computing the horsepower deviation from the second mean horsepower for each engine sensor, re-computing the horsepower deviation ratio for each engine sensor relative to all other engine sensors, comparing the horsepower deviation ratios to predefined limits, and declaring a sensor fault if the horsepower deviation ratio for an engine sensor exceeds a predefined limit.

Abstract: A system is disclosed for determining the total torque required at the main and tail rotors of a helicopter for use in feed-forward rotor torque anticipation which includes a polynomial neural network adapted and configured to predict the aerodynamic torque at the main and tail rotors with the helicopter in motion based upon a plurality of pilot inputs and airframe inputs, a main rotor load map for determining the torque at the main rotor in hover out of ground effects based upon main rotor speed and collective stick position, a tail rotor load map for determining the torque at the tail rotor with the helicopter stationary based upon main rotor speed and pedal position, and a processor for calculating the required total torque at the main and tail rotors by summing the outputs of the polynomial neural network, and the main and tail rotor load maps.

Abstract: 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 rapid attenuation of main and tail rotor torsional frequencies in the power turbine speed signal without compromising phase at low frequencies, and a governor for providing isochronous power turbine speed and rotor speed control based upon the filtered power turbine speed signal.