CESSNA 172S Skyhawk — Service Bulletins

This Technical Service Bulletin (TSB) addresses a potential issue with the aileron control system in Cessna 172 aircraft equipped with a Dynon autopilot. Specifically, it highlights the risk of the aileron crossover cable sagging and potentially binding against the autopilot servo during flight. Although there have been no reported incidents of binding, this bulletin provides preventive measures to ensure safe operation. The bulletin outlines required actions for compliance, including installation of new parts and adjustments to the control system. It is crucial for certified mechanics to perform these actions and document compliance as per FAA regulations. The bulletin is effective indefinitely and aims to enhance the safety and reliability of the aircraft's autopilot system.

• Install new Dynon parts within 12 months or 100 flight hours.
• Specific serial numbers require additional roll servo bracket installations.
• Use a calibrated tensiometer to ensure proper cable tension.
• Torque bridle cable clamp nuts to 35-40 in-lb.
• Do not overtighten the capstan's castle nut beyond 4 in-lbs.