within the hollow portion of the output shaft and is connected preferably through a planetary gear system to drive the output shaft by placing the drive motor within the output shaft essentially the only space requirement is for the output shaft itself application_number US 21979388 A description in fig1 a prior art actuator system such as used on a jet engine nozzle flap is shown at 10 the actuator system 10 comprises generally an output shaft 12 and drive motor 14 for the shaft 12 the shaft 12 is supported for rotation within an opening 16 in the engine fire wall 18 by a bearing 20 in the arrangement shown in fig1 the motor 14 and a portion 22 of the shaft 12 are exposed at the external surface 24 of the fire wall 18 a nacelle 26 is attached to the fire wall 18 and covers the motor 14 and shaft portion 22 to streamline and protect the actuator system it can be seen that the space 28 enclosed by the nacelle 26 is substantial and that the portion of the nacelle 26 over the drive motor 14 therefore accounts for a substantial drag actuator systems according to the present invention are shown at 30 in fig3 and.