# AD 59-18-03: Power Unit Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Curtiss-Wright C634S
- Superseded by: Nothing supersedes this AD
- Product type: Propeller
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4F5CB47160C5CFBE8625696D00434902.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/59-18-03

## The airworthiness directive

59-18-03 CURTISS: Applies to All Models C634S-C400 and C634S-C500 Series Propellers. Compliance required at first propeller overhaul after January 1, 1960, but not later than May 1,1960.

Peculiar wear of power unit motor and mating speed reducer splines in Curtiss C634S- C400 and C634S-C500 Series propellers has been observed at a time short of a full overhaul period. In order to minimize the possibility of such occurrences, provide a new motor rotor assembly which incorporates a longer shaft with splines of a larger pitch diameter and a new mating splined sleeve and high speed drive gear. Modification of the 145295-2 power unit assembly in Curtiss C634S-C400 and C634S-C500 Series propellers to the 163308 power unit assembly accomplishes the desired objective.

(Curtiss Service Bulletin No. C-24 covers this same subject.)

Compliance with AD 59-07-01 is no longer required after compliance with this AD.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS P-825](https://openairdocs.org/tcds/P-825): Curtiss-Wright Corporation; names 1 of 1 models: C634S

## 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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