AD/CESSNA 400/4 - Engine Support Beam - Modification - CANCELLED

This document officially cancels a 41-year-old aviation safety rule that applied to Cessna 400 series aircraft. The original rule (issued in 1967) required owners to modify the engine support beam — the structural part that attaches the engine to the airframe — within 50 hours of flying time to prevent failure. Because every affected aircraft would have completed this mandatory repair decades ago, the Civil Aviation Safety Authority has removed the rule entirely as it is no longer needed. This is essentially a housekeeping measure to clean up outdated requirements.