S-tec 55x Installation Manual |top| Jun 2026

The main control head for lateral and vertical modes.

The system is "Rate Based." The installation manual emphasizes that the Turn Coordinator must be isolated from the aircraft’s vacuum system (if equipped) as it is electrically powered to ensure autopilot functionality even during vacuum system failures. S-tec 55x Installation Manual

Start with the rate gyro. Use a digital protractor to verify alignment. Then mount the computer and servos. Torque servo mounting bolts to the manual’s specification (e.g., 25 in-lbs for roll servo clamps). The main control head for lateral and vertical modes

The S-Tec 55X is a popular autopilot system designed for use in general aviation aircraft. This write-up provides a comprehensive overview of the installation manual for the S-Tec 55X, highlighting key components, installation requirements, and procedures. highlighting key components