An apparatus for use in moving a control surface during operation of an aircraft includes a flexible drive shaft to be connected with an actuator assembly by a coupling assembly. Operation of the actuator assembly operates a force transmission apparatus to move a control surface on an aircraft. The coupling assembly includes an input member connected with the flexible drive shaft and an output member which may be connected with the actuator assembly. A plurality of balls interconnect the input and output members and are rotatable to accommodate relative movement between the input and output members.