COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/46 Amdt 2 Propeller De-Icer System Slip Ring - Inspection 4/90 Applicability: All propeller models HC-B3TN-3C or -3D equipped with propeller de-icer system using spinner bulkhead P/N D-3472 or D-3474, and fitted to Embraer EMB-110 series aircraft. Requirement: Action in accordance with Embraer Service Bulletin No 110-030-0006 Revision 2. Note: Brazilian AD 79-12-02 refers to SB 110-030-0006 initial issue. Compliance: 1. Inspect within 50 hours time in service after 28 November 1979. 2. Repeat inspection at periods not exceeding 50 hours time in service, for an additional 5 inspections. 3. Thereafter, inspect at periods not exceeding 300 hours time in service. 4. Inspection cycle to be repeated for replacement propellers. Background: The aircraft manufacturer advises of the need to inspect for cracking of the resin that attaches the de-icer slip ring. The manufacturer has further revised his Service Bulletin which increased the 200 hour inspection to 300 hours.