COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/56 Pitch Change Rod 10/87 Applicability: All Hartzell propeller models HC-B4(T,M)N-5( ) fitted with either B-3018S-2 or B- 3018T-2 pitch change rods. Note: HC-B4(T,M)N-5 propellers are installed on Garrett TPE-331 turboprop engines. The affected propellers are installed on but not limited to : Dornier DO-228 ( ), Mitsubishi MU-2-( ), Swearingen SA-226, CASA C-212-( ), Beech B100 and Shorts SC-7. Requirement: Action in accordance with Hartzell Service Bulletin No. 153. Compliance: At next overhaul after 30 September 1987 or before 30 September 1988 whichever occur first. Background: The four bladed steel hub propeller type used on Garrett powered installations has experienced failure of the pitch change rod P/N B-3018S-2. Failure of this rod has occurred during ground operation with application of full reverse pitch. Rod failure in this position will cause the propeller to travel deeper into reverse which could cause severe asymmetric thrust conditions or unacceptable engine over temperature conditions.