PURPOSE: To simplify the structure of the device in the caption and reduce the size and weight thereof by providing an electromagnetic valve which works in case of uncontrollable servoactuator and an resetting means which resets the servoactuator to its neutral position when the electromagnetic valve works.

CONSTITUTION: An electromagnetic valve 54 which is changed over by an electric signal from a cockpit in an abnormal case when an servoactuator 11 is uncontrollable by a servocontrol valve 26, is fixed to a casing 12. Then, a resetting means 84 which forcibly moves the spool 34 of the servocontrol valve 26 while giving driving force thereto in an abnormal case, by a piston 51, a link 58, resetting claws 59, 63, a coupling bar 74, first and second levers 75, 78, a roller 80 and a stopping body 83. It is thus possible to simplifier the structure and reduce the size and weight of the device because any other control system is not necessary.