# AD 47-20-02: Oleo Piston

- Type: Airworthiness directive
- Status: Current
- Products: American Champion 11AC and 7AC
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 2,687 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DA272A097F56729386256A38005262BC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-20-02

## The airworthiness directive

47-20-02 AERONCA: (Was Mandatory Note 2 of AD-761-2 and Mandatory Note 2 of AD-759-3.) Applies to 7AC Airplanes Having Serial Numbers 226 to 3721; and 11AC, Serial Numbers 1 to 351.

Compliance required at next periodic inspection but not later than August 1, 1947.

To prevent the oleo strut assembly from separating in flight, replace the fiber piston with aluminum pistons. (Supplementary to Aeronca Service Helps and Hints No. 12 dated February 11, 1947, covers this same subject.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-759](https://openairdocs.org/tcds/A-759): American Champion Aircraft Corp.; names 1 of 22 models: 7AC
- [TCDS A-761](https://openairdocs.org/tcds/A-761): American Champion Aircraft Corp.; names 1 of 4 models: 11AC

## 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: 2,687 (2,687 by airframe model, 0 by engine model)
- Makers: Aeronca 2,481, Champion 202, American Champion 2, Aeronca/Miller/Delaney 1, Aeronca/Obrien 1

Models with the most aircraft:

- [Aeronca 7AC](https://openairdocs.org/model/aeronca-7ac): 1,878 aircraft (airframe model)
- [Aeronca 11AC](https://openairdocs.org/model/aeronca-11ac): 603 aircraft (airframe model)
- [Champion 7AC](https://openairdocs.org/model/champion-7ac): 144 aircraft (airframe model)
- [Champion AERONCA 7AC](https://openairdocs.org/model/champion-aeronca-7ac): 58 aircraft (airframe model)
- [American Champion 7AC](https://openairdocs.org/model/american-champion-7ac): 2 aircraft (airframe model)
- [Aeronca/Obrien 7AC](https://openairdocs.org/model/aeronca-obrien-7ac): 1 aircraft (airframe model)
- [Aeronca/Miller/Delaney 11AC](https://openairdocs.org/model/aeronca-miller-delaney-11ac): 1 aircraft (airframe model)

All 7 models: https://openairdocs.org/ad/47-20-02/models.md
Every aircraft: https://openairdocs.org/ad/47-20-02/aircraft.md

Its text cites no advisory circulars or STCs.

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