Abstract: A Mach hold control circuit for an aircraft autothrottle system provides capture of a Mach number and control thereto while providing a low level of throttle activity also stabilizing the aircraft at maximum range cruise (MRC) Mach numbers and above. The Mach hold control law utilizes a Mach error signal, flight path acceleration signal, average engine EPR signal, and associated logic inputs and when interfaced with the autothrottle system provides a throttle rate command to the aircraft engines via. the throttle and engine control system thereby modulating engine thrust to provide control to desired flight Mach number.

Abstract: Command from engine rating control prevents throttle position from exceeding the value at which the engine operates at its rated power. Flare initiation changes the throttle command signal from a closed loop control signal to a fixed number of degrees per second retard rate, thereby overriding an aft limit switch signal allowing throttles to reach the idle position. A servo feedback arrangement utilizes a tachometer signal and an engine PLA (power lever angle) signal to optimize servo performance and overcome undesired control cable characteristics.

Abstract: A system for processing signals representative of airspeed error and inertial longitudinal acceleration in first and second channels, respectively, and providing cancellation of the turbulence-induced components of the respective signals. Shear detection and compensation circuits are provided in the system for reducing speed wandering in moderate and heavy turbulence. A circuit processing the signal .DELTA.V from the shear detector circuit is utilized to provide a gust bias signal input in the system.

Abstract: Command from engine rating control prevents throttle position from exceeding the value at which the engine operates at its rated power. Flare initiation changes the throttle command signal from a closed loop control signal to a fixed number of degrees per second retard rate, thereby overriding an aft limit switch signal allowing throttles to reach the idle position. A servo feedback arrangement utilizes a tachometer signal and an engine PLA (power level angle) signal to optimize servo performance and overcome undesired control cable characteristics.

Abstract: A Mach hold control circuit for an aircraft autothrottle system provides capture of a Mach number and control thereto while providing a low level of throttle activity also stabilizing the aircraft at maximum range cruise (MRC) Mach numbers and above. The Mach hold control law utilizes a Mach error signal, flight path acceleration signal, average engine EPR signal, and associated logic inputs and when interfaced with the autothrottle system provides a throttle rate command to the aircraft engines via. the throttle and engine control system thereby modulating engine thrust to provide control to desired flight Mach number.

Abstract: A system for processing signals representative of airspeed and inertial longitudinal acceleration in first and second channels, respectively, and providing cancellation of the turbulence-induced components of the respective signals. Shear detection and compensation circuits are provided in the system for reducing speed wandering in moderate and heavy turbulence. A circuit processing the signal .DELTA.V from the shear detector circuit is utilized to provide a gust bias signal input in the system.