Abstract: A system for emergency aircraft control uses at least one engine and lateral fuel transfer that allows a pilot to regain control over an aircraft under emergency conditions. Where aircraft propulsion is available only through engines on one side of the aircraft, lateral fuel transfer provides means by which the center of gravity of the aircraft can be moved over to the wing associated with the operating engine, thus inducing a moment that balances the moment from the remaining engine, allowing the pilot to regain control over the aircraft. By implementing the present invention in flight control programming associated with a flight control computer (FCC), control of the aircraft under emergency conditions can be linked to the yoke or autopilot knob of the aircraft. Additionally, the center of gravity of the aircraft can be shifted in order to effect maneuvers and turns by spacing such center of gravity either closer to or farther away from the propelling engine or engines.

Abstract: An emergency flight control system is disclosed for lateral control using only differential engine thrust modulation of multiengine aircraft having at least two engines laterally displaced to the left and right from the axis of the aircraft in response to a heading angle command .psi..sub.c to be tracked. By continually sensing the heading angle .psi. of the aircraft and computing a heading error signal .psi..sub.e as a function of the difference between the heading angle command .psi..sub.c and the sensed heading angle .psi., a track control signal is developed with compensation as a function of sensed bank angle .PHI., bank angle rate .phi., or roll rate p, yaw rate .tau., and true velocity to produce an aircraft thrust control signal ATC.sub..psi.(L,R).

Abstract: A digital longitudinal Aircraft Propulsion Control (APC) system of a multiengine aircraft is provided by engine thrust modulation in response to comparing an input flightpath angle signal .gamma.c from a pilot thumbwheel or an ILS system with a sensed flightpath angle .gamma. to produce an error signal .gamma.e that is then integrated (with reasonable limits) to generate a drift correction signal to be added to the error signal .gamma.e after first subtracting a lowpass filtered velocity signal Vel.sub.f for phugoid damping. The output error signal is multiplied by a constant to produce an aircraft thrust control signal ATC of suitable amplitude to drive a throttle servo for all engines, each of which includes its own full-authority digital engine control (FADEC) computer. An alternative APC system omits sensed flightpath angle feedback and instead controls the flightpath angle by feedback of the lowpass filtered velocity signal Vel.sub.f which also inherently provides phugoid damping.

Abstract: A backup flight control system for controlling the flightpath of a multi-engine airplane using the main drive engines. The backup flight control system comprises an input device for generating a control command indicative of a desired flightpath, a feedback sensor for generating a feedback signal indicative of at least one of pitch rate, pitch attitude, roll rate and roll attitude, and a control device for changing the output power of at least one of the main drive engines on each side of the airplane in response to the control command and the feedback signal.

Abstract: An acoustic noise elimination assembly having a capability for disrupting the continuity of fields of sound pressures forwardly projected from fans or rotors of a type commonly found in the fan or compressor first stage for air-breathing engines, when operating at tip speeds in the supersonic range. The assembly incudes a tubular cowl 12 defining a duct for delivering an airstream axially into the intake for a jet engine E and a sound barrier 14, defined by a plurality of intersecting flat plates or struts 14a-14d having a line of intersection coincident with a longitudinal axis of the tubular cowl, which serves to disrupt the continuity of rotating fields of multiple pure tonal components of noise.