COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/66 Blade Pitch Change Knob 9/94 DM Applicability: All model HC-E4A-3A/E10950( ) propellers prior to and including S/N HJ198 installed on Beech 1900D aircraft. Requirement: Unless previous carried out action in accordance with Hartzell Alert Service Bulletin A190. Note: FAA AD 94-10-01 Amdt 39-8908 refers. Compliance: As specified in the Requirement Document effective from 6 July 1994. Background: The manufacturer has advised that failure of the pitch change knob attachment screws can cause vibration and failure of the propeller to completely go into the feather position.