# AD 47-21-20: Oil Pressure Gage Line Restrictor

- Type: Airworthiness directive
- Status: Current
- Products: Sky Enterprises RC-3
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 126 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B31F64729A88DDA586256A5600666D3C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-21-20

## The airworthiness directive

47-21-20 REPUBLIC: (Was Mandatory Note 10 of AD-769-2.) Applies to Model RC-3 Aircraft Serial Numbers 426 Through 484, Except 446, 447, 452, 455, 460, 468, 471, 473, 475, 480, 481 and 483.

Compliance required not later than the next 25 hours of operation subsequent to July 1, 1947, and in any case not later than September 1, 1947.

In order to prevent excessive loss of oil through oil pressure gage line in case of its failure, install a restrictor fitting at the engine end of that line.

(Seabee Service Bulletin No. 13, dated March 17, 1947, covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-769](https://openairdocs.org/tcds/A-769): Sky Enterprises Inc.; names 1 of 1 models: RC-3

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 126 (126 by airframe model, 0 by engine model)
- Makers: Republic 122, Downer 2, Republic Aviation Corp USA 1, Simuflight Seattle-1-Stol 1

Models with the most aircraft:

- [Republic RC-3](https://openairdocs.org/model/republic-rc-3): 122 aircraft (airframe model)
- [Downer RC-3](https://openairdocs.org/model/downer-rc-3): 2 aircraft (airframe model)
- [Republic Aviation Corp USA SEABEE RC-3](https://openairdocs.org/model/republic-aviation-corp-usa-seabee-rc-3): 1 aircraft (airframe model)
- [Simuflight Seattle-1-Stol RC-3](https://openairdocs.org/model/simuflight-seattle-1-stol-rc-3): 1 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/47-21-20/models.md
Every aircraft: https://openairdocs.org/ad/47-21-20/aircraft.md

Its text cites no advisory circulars or STCs.

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