COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/65 Hub Pilot Tube Bore Inspection 5/94 Applicability: All HC-B4 series propellers which may have been previously installed on MU-2 series aircraft and have not had the hub bores inspected in accordance with Hartzell Alert SB A182 or A183. Note 1: Subject propellers are installed on but not limited to Beech F90 King Air, A100 and A100A King Air, B100 King Air, CASA C-212-CB, CASA C-212-CC, CF, DeHaviland Heron - Saunders Conversion ST-27B, Dornier Do 228-100, -101, -200, -201, -202 and -212, Embraer EMB-121A1 Xingu, Fairchild SA226-TB Merlin IIIB, Let L-410A and Shorts SC-7 series 3, variant 200. Note 2: Hubs previously inspected in accordance with AD/PHZL/64 are exempt from the requirements of this Directive. Requirement: Action in accordance with Hartzell Alert SB A186 dated 25 January 1994. Note: FAA AD 94-03-11 amdt 39-8818 refers. Compliance: As specified in the requirement document. Background: The propeller manufacturer has expressed concern that a large number of 4 bladed hubs originally supplied to Mitsubishi may have seen service on MU-2 series aircraft and due to the higher operating stresses when fitted to these aircraft the hub pilot tube bores require inspection for signs of fatigue cracking.