Abstract: An automatic flight control system for an aircraft having a control surface 28 and including a gyro 12 having an output applied through an attitude filter 14 to the input of a roll rate circuit 16 and a summing amplifier 18. The roll rate circuit 16 generates a rate signal that is applied to a summing amplifier 20 generating a roll rate control signal. The roll rate control signal is input to a roll servo amplifier 22. The servo amplifier 22 combines the rate control signal with a motor velocity signal from a motor velocity detector as part of a roll servomotor 26. Mechanically interconnected to the roll servomotor 26 is the control surface 28 for maneuvering an aircraft about its roll axis. Also, input to the summing amplifier 18 are aircraft command signals from a command block 10 where the authority of such signals is set by a limiter 30.

Abstract: A horizontal situation indicator having a heading card direct-driven by a directional gyro is provided. Relative positioning of the heading card and one or more navigation indicators is determined by sensing an electrical differential between a transducer associated with a heading card and a transducer associated with each navigation indicator. Spring-loaded clutch mechanisms are provided to allow adjustment of the navigation indicators without applying a torque to the heading card and gyro.

Abstract: A signal varying over a wide dynamic range from a source (10) is input to a summing amplifier (12) along with the output of an adjustable reference generator (14). An error signal output of the summing amplifier (12), a subtraction of the output of the reference generator (14) from the input signal source (10), is applied to a rate network consisting of a capacitor (16) and a resistor (18), with the latter in a feedback loop for an amplifier (20). The output of the reference generator (14) is adjusted to maintain the error signal within the operating limits of the summing amplifier (12) by monitoring the output of the amplifier. During the time interval when the adjustment of the generator (14) is made, a compensating network (24) maintains the output of the amplifier (20) at the level previous to the adjustment interval. This provides a continuous output voltage at a terminal (22) that varies over an expanded range with reference to the input signal.

Abstract: A pressure responsive system includes a piezoresistive transducer (10) mounted in a housing (20) with the temperature of the housing and the transducer maintained by heater (22). Operating characteristics of the transducer (10) are normalized by a normalization circuit (18) that interconnects the output of the transducer to a heater control (24). The heater control (24) generates a control signal to the heater (22). A signal varying with pressure is output from the normalization circuit (18) and applied to a DC stabilized gain stage (26) that is corrected for zero signal error and produces an amplification of the transducer output for application to a function generator (12). The function generator (12) converts an absolute pressure signal from the transducer (10) into a signal varying with pressure altitude for utilization in an autopilot system.

Abstract: An automatic pitch trim system responds to the output of a torque detector (34) to provide an input signal to a gain normalization circuit (36). A limiter (38) responds to the gain normalization circuit (36) to produce a limited authority trim signal to a summing amplifier (48). Also connected to the normalization circuit (36) is a window generator (42) that responds to the input signal to activate a time delay (46). The time delay (46) generates a control signal to a signal gate (40) having an input connected to the normalization circuit (36). Under the control of the time delay (46), the output of the mormalization circuit (36) is gated through to the summing amplifier (48) to be combined with the output of the limiter (38) into a signal that is applied to a trim servo amplifier (50). The servo amplifier (50) generates an energizing voltage for driving a trim servo motor (44) coupled to trim tabs (52).

Abstract: Aircraft altitude is maintained through control surfaces responsive to an altitude hold control voltage varying with the output of a pressure transducer. The pressure transducer provides an output varying in a linear relationship with absolute atmospheric pressure and this output is applied to the input of a nonlinear circuit that generates a voltage varying linearly with altitude. A digital-to-analog converter generates an altitude reference voltage in response to an altitude hold engage signal and this voltage is combined in a summing amplifier with the voltage varying linearly with altitude. Also summed with the altitude reference voltage and the voltage varying linearly with altitude in the summing amplifier is a standard reference voltage. The total summation that is made in the summing amplifier produces the altitude hold control voltage as an output thereof.