Emergency multiengine aircraft system for lateral control using differential thrust control of wing engines

An emergency flight control system for heading angle .psi. of a multiengine aircraft using engine thrust modulation for differential lateral control of said multiengine aircraft having at least two engines laterally displaced from a longitudinal axis thereof comprising,

• means for independently entering a heading angle command .psi..sub.c to be tracked by said aircraft,
• means for continually sensing said heading angle .psi. of said aircraft,
• means for computing a heading error signal .psi..sub.e as a function of the difference between said heading angle command .psi..sub.c and said sensed heading angle .psi.,
• means for compensating said error signal .psi..sub.e as a function of sensed bank angle rate .phi. for dutch roll damping and of sensed bank angle .PHI., yaw rate .tau. and velocity for efficient turn coordination to produce an aircraft thrust control signal ATC.sub..psi.(L,R), and
• means for differentially applying said aircraft thrust control signal to said left and right engines with equal amplitude and opposite sign with the negative sign applied to the control signal on the side of the aircraft to which a turn is required to reduce said error signal toward zero.