# AD 50-15-01: Mixture Control Rework

- Type: Airworthiness directive
- Status: Current
- Products: Grumman American G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 34 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0C050542E19EE5FA86256A38005B3DCF.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/50-15-01

## The airworthiness directive

50-15-01 GRUMMAN: Applies to All Model G-21A Aircraft (Converted JRF-5, JRF- 6B) Equipped With Reverse Direction Mixture Controls.

Compliance required not later than next 25-hour inspection.

To conform with conventional mixture control operation ("forward" for full rich position) on aircraft equipped with Bendix NAR9B carburetors with manual mixture control, rotate the position of the mixture bellcranks 180 degrees on the carburetors and reverse the tooth segments on the cockpit control end for end. Revise the cockpit control placard accordingly.

On aircraft equipped with Bendix NAR9C2 carburetors with automatic mixture control, the cockpit quadrant is already arranged in the correct sense and requires no revision. It should be noted that an additional Manual Lean position is provided forward of Full Rich and caution must be exercised to prevent inadvertently positioning the control incorrectly if the Manual Lean sector of the quadrant is retained.

This supersedes AD 48-14-02.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS TC 654](https://openairdocs.org/tcds/TC%20654): Frakes Aviation; names 1 of 2 models: G-21A (Army OA-9; Navy JRF-1; -2; -3; -4; -5; and -6B)

## 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: 34 (34 by airframe model, 0 by engine model)
- Makers: Grumman 34

Models with the most aircraft:

- [Grumman G-21A](https://openairdocs.org/model/grumman-g-21a): 34 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/50-15-01/models.md
Every aircraft: https://openairdocs.org/ad/50-15-01/aircraft.md

Its text cites no advisory circulars or STCs.

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