Abstract: A control system for insuring synchronized operation of engines, such as those in a propeller driven aircraft, wherein a master engine dictates the speed and phase condition of a slave engine. The system features a timing generator in connection with the master engine and a speed detector in connection with the slave engine which are interrelated to produce a direct and accurate signal of an overspeed or underspeed, out of phase, condition of the slave engine, when such occurs. This signal is directed through an amplifier computer portion of the control system which embodies a unique dual servo arrangement for selectively routing the signal through different output channels. Low level outputs are modulated for a "soft" correcting influence. In any case, the output of the computer amplifier portion of the control system is directed to provide a representative current value in the windings of an electromagnet embodies in an improved governor operatively related to the slave engine.