Variable pitch propeller control system

A variable pitch propeller and control system comprising:

• a propeller including a hub rotatable about a rotational axis, at least two propeller blades journal ed in said hub for rotation about axes crossing said rotational axis for blade pitch control as well as for rotation about said rotational axis with said hub;
• a pitch change mechanism, including a motor, for rotating said blades in unison about said crossing axes between at least a coarse pitch position and a fine pitch position;
• a main pitch control for normally operating said pitch change mechanism;
• and
• a secondary control operating said pitch change mechanism in response to the existence of at least one undesirable propeller condition and including a target carried by said propeller, a target pickup for sensing the target and generating a target signal, a function generator receiving said target signal and generating at least one propeller condition signal indicating when at least one said undesirable propeller condition occurs, and a logic device responsive to said propeller condition signal and connected to said pitch change mechanism and causing said pitch change mechanism to change the pitch of said blades to a pitch whereat said at least one undesirable propeller condition no longer exists.