Emergency control aircraft system using thrust modulation

An emergency control servo system for using thrust modulation for longitudinal control of a multiengine aircraft having a throttle servo for control of all engines in unison, comprising

• means for independently entering a flightpath angle command to be maintained and producing a flightpath angle command signal .gamma.c,
• means for sensing aircraft longitudinal velocity and producing a lowpass filtered velocity signal,
• means for subtracting said lowpass filtered velocity signal from said flightpath command signal .gamma.c to produce a flightpath error signal .gamma.e,
• means for forming a limited integral as a function of said error signal and
• means for adding said limited integral to said flightpath error signal .gamma.e for producing an output control signal ATC to said throttle servo, thereby to adjust thrust of said engines to reduce said flightpath error signal .gamma.e toward zero.

An emergency control system for using thrust modulation for longitudinal control of a multiengine aircraft having aircraft dynamic sensors of flight angle .gamma. and aircraft velocity Vel, a flight control computer and a single throttle servo for control of all engines in unison and having means for both independently entering a flightpath angle command to be maintained and producing a flightpath angle command signal .gamma.c said emergency system comprising a closed loop servo system for producing a throttle command signal ATC for said throttle servo in accordance with the following control law in the S-plane:

• ATC=Ksc(Kvi/S*.gamma.e*Ke+(.gamma.e*Ke-B)Kve)
• where:
• Ksc is a constant for proportioning said control output signal of said closed loop servo system to said throttle servo;
• .gamma.e=.gamma.c-.gamma., and .gamma. is the sensed flightpath angle scaled by a constant Kgma to be proportional to the command input .gamma.c in volts per degree;
• B=Kvel*Vel.sub.f, and Vel.sub.f equals Vel*50/(S+50),
• Ke and Kve are scaling constants;
• Kvi is a scaling constant for the integral .gamma.eKe/S.

An emergency control system for using thrust modulation for longitudinal control of all engines in unison and a flight control computer and a single throttle servo for control of all engines in unison, means for sensing aircraft velocity and producing a signal Vel proportionate thereto, and further having means for both independently entering a flightpath angle command to be maintained and producing a flightpath angle signal .gamma.c, and said emergency control system comprising a closed loop servo system producing a throttle command signal ATC for said single servo, a throttle command ATC for all engines as a function of velocity feedback in accordance with the following control law in the S-plane:

• ATC=Ksc*.gamma.e(Kvi/S+Kve)
• where:
• .gamma.e=.gamma.c-B,
• B=Kvel*Vel.sub.f,
• Vel.sub.f =50/(S+50)*Ve,
• Ksc is a scaling constant, and
• Kvi is a scaling constant.