COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Propellers - Variable Pitch - Hartzell
AD/PHZL/58 Piston Nut B474 7/89 DM Applicability: All Hartzell propellers model HC-A6A-3 installed on Shorts SD3-60-300 aircraft. Requirement: 1. Action in accordance with Procedure 1 of Hartzell SB No 163.
2. Action in accordance with Procedure 2 of Hartzell SB No 163.
Compliance: For Requirement 1. Within 100 hours time in service from 19 May 1989, or by 9 June 1989 whichever occurs first. Thereafter re-inspect at intervals not exceeding 100 hours time in service until propeller is modified in accordance with Requirement 2.
For Requirement 2. At next propeller overhaul or by 30 June 1991, whichever occurs first.
Background: The manufacturer has advised that the B-474 nut may not fully contact the piston when correctly torqued and could cause an inadvertent blade angle change. Pending introduction of a new nut indexing of relevant parts is required.