COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/71 Counterweight Clamp Bolts 5/98 Applicability: All Hartzell Propeller Inc. Model HC-E4A-3(A,I) propellers with serial numbers HJ1 to HJ654. Requirement: Identify and replace defective propeller blade counterweight clamp bolts with improved bolts in accordance with Hartzell Propeller Inc. Service Bulletin (SB) No. HC-SB-61-219, Revision 1, dated July 2, 1996. Note 1: Subject propellers are installed on but not limited to Raytheon Beech 1900D series aircraft. Note 2: FAA AD 98-02-07 and Hartzell SB HC-SB-61-219 refer. Compliance: Within 45 days or 400 hours time in service (TIS) after the effective date of the AD, whichever occurs first. This airworthiness directive becomes effective on 23 April 1998. Background: The manufacture has advised that a counterweight clamp installed on an HC-E4A-3A propeller separated in flight. The clamp passed through the spinner dome and struck an adjacent blade resulting in a blade failure. One of the two socket head screws attaching the counterweight clamp broke. The failure was due to a defective socket head cap screw.