COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hamilton Standard AD/PHS/14 Amdt 2 Titanium Nitrided Transfer Tube 10/93 DM Applicability: All model 14RF-9, -19 and -21 and 14SF-5, -7, -11, -15, -17, -19 and -23 propellers and Hamilton Standard-British Aerospace Model 6/5500/F-1 propeller. Note: Subject propellers may be installed on but not limited to EMB-120 Series, SAAB-340B, ATR42-100, -300, -320, ATR72-101, -201, DHC-8-100, -300, -314, CASA CN-235, -235-100, Canadair CL215T and BAe ATP aircraft. Requirement: Unless previously carried out action in accordance with the Technical Requirements of FAA AD 93-06-06 amdt 39-8531 which supersedes FAA AD T91-11-51. Note: Hamilton Standard ASB 14RF-21-61-A39 applicable to 14RF-21 propellers, ASB 14RF-9-61-A57 applicable to 14RF-9 propellers, ASB 14RF-19-61-A26 applicable to 14RF-19 propellers, ASB 14SF-61-A61 applicable to 14SF series propellers and ASB 6/5500/F-61-A21 applicable to Hamilton Standard-British Aerospace 6/5500/F-1 propellers. Compliance: As specified in the requirement document with revised effective date of 9 August 1993. Background: During investigation of a previously removed quill worn to its wear limits, it was discovered that the quill would not engage with the propeller transfer tube. The previous amendment reduced the allowable wear in the quill, reduced the hours between inspections and detailed terminating action. This amendment requires any PCU ballscrew quill, that has either been mated to a titanium nitrided transfer tube or that have no records showing to which transfer tube type the PCU ballscrew quill was mated, must be replaced with a new quill or a quill that has never been mated with a titanium nitrided transfer tube.