# AD 51-23-04: Rotor Link Assemblies

- Type: Airworthiness directive
- Status: Current
- Products: Sikorsky S-51
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/20ED29FB6BF2E66186256A55006B7258.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/51-23-04

## The airworthiness directive

51-23-04 SIKORSKY: Applies to All Model S-51 Helicopters.

Compliance required as indicated.

1. Compliance required prior to next flight.

Inspect all main rotor link assemblies (P/N S510348) received from the manufacturer between June 1 and September 6, inclusive for location of the identification stamp "F". Links with the "F" metal-stamped in the critical area on the inner faces of the ears should be retired from service. Those with the "F" stamped on the outer faces or on noncritical areas of the inner faces of the ears should be polished locally with emery and crocus cloth to remove the "F" and the links may be returned to service. (See Figure 6.)

AD 51-23-04

(Sikorsky Information Circular No. 175, dated September 7, 1951, covers this same subject.)

2. Main rotor link assemblies (P/N S510348) shall be retired from service when a total flight time of 960 hours on the links has been accumulated.

(Sikorsky Information Circular No. 122, Revision B, dated September 10, 1951, covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H-2](https://openairdocs.org/tcds/H-2): Sikorsky Aircraft Corporation; names 1 of 1 models: S-51

## 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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