# AD 54-12-02: Vibratory Stresses

- Type: Airworthiness directive
- Status: Current
- Products: McCauley Propeller Systems AAF 41D5926 and D-1093
- Superseded by: Nothing supersedes this AD
- Product type: Propeller
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7821D3715358982F862569650069EA05.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/54-12-02

## The airworthiness directive

54-12-02 MCCAULEY: Applies to All McCauley Propellers Having 41D5926 Hub With SS-135-6 Blades and D-1093 Hub With SS-135-6M or SS-138-6 Blades.

Compliance required as indicated.

On the basis of satisfactory vibration stress surveys conducted on the 102-inch diameter configuration, these propellers were approved vibration wise for installation on the Continental W-670-6A and W-670-6N and Lycoming R680 engines. When installed on the Continental engine, the propeller must be indexed in the 0 degree position (blades in line with the crankthrow) and operation is to be restricted between 1,500 and 1,650 r.p.m.

Additional approval were given for the installation of propellers in reduced diameters at a time when the effects on the vibratory stresses resulting from such a reduction were not generally appreciated. Accordingly, some installations were made where the propeller diameter was reduced, as in the Fairchild M-62C. Service experience with this installation and a more thorough knowledge of the vibration problems indicate that diameters below the normal 2 percent reduction that is usually permissible on the basis of a stress survey have resulted in serious failures. Accordingly, to preclude additional propeller failures, the following should be performed. Compliance required prior to July 1, 1954.

  (a) To preclude failures due to vibratory conditions, remove from service all of these propellers in diameters outside the 102- to 100-inch limits.

  (b) To preclude fatigue failures due to corrosion or galling in the blade shank region and/or hub, disassemble propellers maintained in service (diameters 102 to 100 inches) and magnetically inspect hub and blades at intervals not exceeding 100 hours. The propeller blade and hub surface must be kept free from corrosion at all times.

If 100 hours operating time has not been accumulated since an inspection was conducted on the propeller as provided in AD 47-43-09, it will be satisfactory to operate until 100 hours have been accumulated.

This supersedes AD 47-43-09.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS TC 781](https://openairdocs.org/tcds/TC%20781): McCauley Propeller Systems; names 1 of 2 models: AAF 41D5926
- [TCDS TC 815](https://openairdocs.org/tcds/TC%20815): McCauley Propeller Systems; names 1 of 1 models: D-1093

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

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