Aircraft flight control systems and methods

An aircraft flight control system comprising:

• a control rod;
• a bearing assembly for connection to aileron control surfaces of the aircraft, the bearing assembly mounting the control rod to allow for rotational and longitudinal movements thereof in response to applied roll and pitch command inputs, respectively, wherein
• the bearing assembly has an outer fixed position bearing member and a rotatable inner bearing member coaxially positioned with the outer bearing member, the inner bearing member being coupled operatively to the outer bearing member to allow for rotational movements of the inner bearing member relative to the longitudinal axis of the control rod, and wherein
• the control rod and the inner bearing assembly collectively define opposed races and include an axially aligned series of spherical bearings positioned within the opposed races to operatively spline-connect the control rod to the inner bearing assembly so as to allow for independent simultaneous longitudinal and rotational movements of the control rod relative to the longitudinal axis thereof such that longitudinal movements of the control rod are isolated from the bearing member but rotational movements of the control rod are transferred to the bearing member to cause rotation thereof and thereby allow operation of the aileron control surfaces, the system further comprising,
• an elevator torque tube assembly capable of operative connection to an elevator control surface of the aircraft, and
• an articulated linkage operatively connecting the control rod to the elevator torque tube assembly so that roll command inputs to the control rod are isolated from the torque tube but pitch command inputs to the control rod are transferred by the articulated linkage to the torque tube to allow operation of the elevator control surface, wherein the articulated linkage comprises:
• (i) a rotational bearing member for receiving a terminal end of the control rod to allow for independent rotational movements therebetween, and
• (ii) a control fork connected at one end to the bearing member and connected at an opposite end to the torque tube assembly to allow for respective articulated movements of the control fork relative to the bearing member and the torque tube assembly about respective articulation axes perpendicular to the control rod.

An aircraft pitch and roll control system comprising:

• a control rod which is movable rotationally and longitudinally in response to applied roll and pitch command inputs, respectively, the control rod having a plurality of circumferentially spaced apart longitudinal races,
• a bearing assembly having a fixed position outer bearing member and an inner bearing member capable of connection to an aircraft's aileron control surfaces, wherein
• the inner bearing member is coupled operatively to the outer bearing member to allow for relative rotational movements about the longitudinal axis of the control rod in response to roll command inputs, and wherein
• the inner bearing member defines inner races that are opposed to the longitudinal races of the control rod, wherein the inner and longitudinal races of the control rod and the inner bearing assembly, respectively, include axially aligned series of spherical bearings positioned therewithin to operatively spline-connect the control rod to the inner bearing assembly so as to allow for independent simultaneous longitudinal and rotational movements of the control rod relative to the longitudinal axis thereof such that longitudinal movements of the control rod are isolated from the inner bearing member but rotational movements of the control rod are transferred to the inner bearing member responsively causing rotation of the inner bearing member relative to the outer bearing member,
• an elevator torque tube having a bell crank, the elevator torque tube being capable of operative connection to an elevator control surface of the aircraft, and
• an articulated linkage operatively connecting the control rod to the bell crank of the elevator torque tube, wherein the articulated linkage comprises:
• a bearing member for receiving a terminal end of a control rod to allow for independent rotational movements therebetween, and
• a control fork connected at one end to the bearing member and connected at an opposite end to the bell crank to allow for respective articulated movements of the control fork relative to the bearing member and the bell crank about respective articulation axes perpendicular to the control rod, wherein
• roll command inputs to the control rod are isolated from the torque tube but pitch command inputs to the control rod are transferred by the articulated linkage to the torque tube.

A method of providing independent and simultaneous rotational and longitudinal movements of an aircraft control rod in response to roll and pitch command inputs thereto, the method comprising:

• (a) establishing an operative spline connection between the control rod and a bearing assembly having a fixed position outer bearing member and a rotational inner bearing member connected operatively to aileron control surfaces of the aircraft which allows for independent simultaneous longitudinal and rotational movements of the control rod relative to the longitudinal axis thereof such that longitudinal movements of the control rod are isolated from the inner bearing member in response to pitch command inputs but rotational movements of the control rod are transferred to the inner bearing member in response to roll command inputs thereby causing rotation of the inner bearing member relative to the outer bearing member;
• and
• (b) establishing an operative connection between the control rod and an articulated linkage connected to an elevator torque tube assembly associated operatively with an elevator control surface of the aircraft so that roll command inputs to the control rod are isolated from the torque tube assembly but pitch command inputs to the control rod are transferred by the articulated linkage to the torque tube assembly, wherein
• step (a) comprises (ai) providing the control rod and the inner bearing assembly collectively defined opposed races, and (aii) positioning within the opposed races an axially aligned series of spherical bearings, and wherein
• step (b) comprises (bi) providing a rotational bearing member for receiving a terminal end of the control rod to allow for independent rotational movements therebetween, and (ii) connecting a control fork at one end thereof to the bearing member and connecting the control fork at an opposite end thereof to the torque tube assembly to allow for respective articulated movements of the control fork relative to the bearing member and the torque tube assembly about respective articulation axes perpendicular to the control rod.