# AD 47-47-13: Hartzell Propeller Hub Counterweight

- 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- Superseded by: Nothing supersedes this AD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/33D2B6CF7028BD6686256A560066A4D2.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-47-13

## The airworthiness directive

47-47-13 REPUBLIC: (Was Mandatory Note 11 of AD-769-2.) Applies to Model RC-3 Aircraft.

To be accomplished not later than next 100-hour inspection or January 15, 1948.

If the Hartzell propeller hub model on your airplane is HC-12X20-3, determine the counter weight length and position on the hub in order that the hub designation can be amended as necessary in accordance with the following:

  (a) Plain counterweights 4.650 inches in length - the designation HC-12X20-3 is unchanged.

  (b) Notched counterweight 4.50 inches in length - add suffix letter "C" to designation so that it reads HC-12X20-3C.

  (c) Plain counterweight 4.50 inches in length - a 1/8-inch slug must be added to these counterweights and suffix letter "A" added to the hub designation so that it reads HC- 12X20-3A. Any of these hubs on which the slugs have not been added to the counterweights must be removed from service until the counterweight slugs are affixed.

Revise the reverse thrust operation placard as follows:

For airplanes with 6A8-215-B8F engines, Serial Numbers 23001 to 23280, inclusive, and HC12X20-2 propeller:

WARNING - Reversing propeller in flight prohibited. Operate reverse lever in low pitch only. Maximum 1,750 r.p.m. in reverse pitch.

For airplanes with 6A8-215-B8F engines, Serial Numbers 23001 F to 23280 F, inclusive, and 23281 and up and all -B9F engines and

  (1) HC-12X20-3 or 3-A propellers:

WARNING - Reversing propeller in flight prohibited. Operate reverse lever in low pitch only. Maximum 2,300 r.p.m. in reverse pitch. Or

  (2) HC-12X20-2 or -3C propellers:

WARNING - Reversing propeller in flight prohibited. Operate reverse lever in low pitch only.

## 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/47-47-13/models.md
Every aircraft: https://openairdocs.org/ad/47-47-13/aircraft.md

Its text cites no advisory circulars or STCs.

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