1AD/PMC/15 Amdt 1 - Propeller Attachment - Modification and Inspection

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Propellers - Variable Pitch - McCauley

AD/PMC/15

Amdt 1

Propeller Attachment - Modification and Inspection

13/95

Applicability: All model 3AF34C series propellers fitted to Continental GTSIO-520 engines.

Requirement: 1. Remove and discard propeller mounting stud nuts and washers. Install new nuts (deleting the washers) and torque to 108-115 Nm (80-85 pounds feet) ensuring the threads on the nuts and studs are not lubricated and perfectly clean. New nuts shall be used each time a propeller is re-installed. Remove any torque value decal from the hub ensuring removal technique does not damage the hub.

2. Check for loss of torque on the propeller mounting stud nuts by applying a measured torque 108-115 Nm (80-85 pounds feet). Remove any torque value decal from the hub ensuring removal technique does not damage the hub.

3. In the event of any substantial loss of torque of the mounting stud nuts being found or of excessive rough running being experienced by the associated engine, remove the propeller and inspect the mounting studs and dowels, propeller attachment face and propeller shaft flange for signs of cracking or excessive fretting. When such indications are found, replace all mounting studs and dowels with new items. Ensure all threads are kept perfectly clean of lubricant. Repair or replace other damaged components as necessary. Remove any torque value decal from the hub ensuring removal technique does not damage the hub.

Compliance: 1 Unless previously carried out within 10 hours time in service after 7 December 1995.

2. At intervals not exceeding 100 hours time in service.

3. As required.

Background: This amendment being raised to retain the non lubricated torque requirements on the threads of McCauley 3AF34C series propellers which differ from the requirements specified in McCauley SL 1992-18B. The requirement to apply a dry thread torque only applies to these propellers when they are fitted to the Continential GTSIO-520 engine powered aircraft.