COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Propellers - Fixed Pitch
AD/PFP/16 Ken Brock Propeller Hub Extension 3/91
Applicability: Any propeller hub extender supplied by Ken Brock and fitted to any Lycoming 0-320 or 0-360 powered amateur built aircraft.
Requirement: 1. Remove propeller from hub extender and measure extender wall thickness.
2. If wall thickness is approximately 12 mm (.50 inches) refit propeller. If wall thickness is approximately 7 mm (.25 inches) replace hub extender before further flight.
Compliance: At next scheduled aircraft inspection or by 31 July 1991, whichever occurs first.
Background: Due to insufficient wall thickness a hub extender supplied by Ken Brock has suffered a fatigue failure.