US Patent 10000275 Aircraft hybrid flight control system

An aircraft hybrid flight control system comprising a manual control element, a mechanical transmission interposed between the manual control element and a control surface, an electromechanical actuator and a coupling unit configured to connect selectively the control surface to the mechanical transmission in a manual control mode and to the electromechanical actuator in a fly-by-wire control mode; the coupling unit is configured to maintain the mechanical transmission in a condition of substantial continuity with said control surface even in fly-by-wire mode, but for a freedom of relative motion of pre-set amplitude.