# AD 58-04-02: Split Ring

- Type: Airworthiness directive
- Status: Current
- Products: Hartzell Propeller HC-93Z20-2 with STC SA4-2
- Superseded by: Nothing supersedes this AD
- Product type: Propeller
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/EB0D02864D996A5286256965004BC997.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/58-04-02

## The airworthiness directive

58-04-02 HARTZELL: Applies to All HC-93Z20-2C and -2B Propellers. The -2C Propellers Are Installed on All Beech E50 and F50 Aircraft, and -2B Propellers Are Installed on Some Cessna T-50 With Lycoming R-680 Engines and on Mansdorf Conversion of Grumman G- 44 With Lycoming R-680 Engines (STC SA4-2).

Compliance required prior to next flight for propellers with hub Serial Numbers 100A through 361A and above.

The recent failure of an A-1307 split ring, which the records show had less than 180 hours' operating time, permitted the propeller blade to leave the hub. In order to minimize the possibility of the occurrence of this type of serious failure, the present split ring must be replaced with a strengthened split ring. Accordingly, replace A-1307 split ring with A-1331 split ring. This also requires replacing A-1303 bearing with A-1303A bearing. Modified propellers should be stamped HC-93Z20-2B1 or -2C1. New propellers so stamped will incorporate modified split rings and bearings.

(Hartzell Service Bulletin No. 55 covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS P-891](https://openairdocs.org/tcds/P-891): Hartzell Propeller Inc.; names 1 of 4 models: HC-93Z20-2

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

## Related documents

- [STC SA4-2](https://openairdocs.org/stc/SA4-2): Lycoming R-680-E, E3A or E3B engines and Hartzell 93Z propellers.. Gander Aircraft Corp, Named in the applicability

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