A new NATO patrol hydrofoil missile (PHM) is being developed, with the first lead ship nearing completion. The automatic control system (ACS), which provides the foilborne vehicle control, is newly developed for PHM. The ACS development evolved primarily from two previous hydrofoil control systems: Tucumcari and High Point.The ACS functional configuration was evolved using a highly developed digital simulation of the craft, control hardware, and sea conditions. Extensive failure mode and effect analyses were used to evolve a ship/control system configuration which is fail-safe for single-level failures within the system. From the overall performance, stability, and failure analyses, significant evolutions in the control system configurations resulted.The ACS hardware is newly developed for PHM, building around new families of integrated circuit building blocks. A companion to the ACS is the self-test system, which provides verification that the total ACS is operating properly, and provides fault isolation to the shipboard replaceable unit in the event of a failure.