COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Piper PA-31 Series Aeroplanes
AD/PA-31/39 Propeller Feather Assist Spring - Installation 12/75
Applicability: All model PA-31P fitted with Hartzell propellers HC-C3YN-2L, HC-C3YN-2LF, HC-C2YN-2LA, or HC-C3YN-2LAF.
Requirement: Install propeller feather assist springs in accordance with Piper SB No. 470.
Note: Operators are advised to refer to Piper SB No. 458, which recommended operational procedures to be observed in the event of a propeller overspeed.
Compliance: Within 100 hours time in service after 31 December 1975.