# AD 79-02-03: Engine Restart

- Type: Airworthiness directive
- Status: Current
- Products: Grumman American G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) with STC SA1-52
- Effective: January 29, 1979
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-3400
- Registered aircraft: 34 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7CE5C8655175617586256A38005B78B9.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/79-02-03

## The airworthiness directive

79-02-03 GRUMMAN: Amendment 39-3400. Applies to all G-21A aircraft that have been modified to incorporate Hartzell propellers and governor crossfeed systems in accordance with Supplemental Type Certificate No. SA1-52, and are certificated in all categories.

Compliance required within 50 hours' time in service or 15 days, whichever occurs first, after the effective date of this AD, unless previously accomplished.

To preclude the inability to restart an engine and the simultaneous loss of the remaining engine, install the following placard adjacent to the emergency unfeather valve in full view of the pilot and operate the aircraft thereafter in accordance with these terms:

"ENGINE RESTART: ATTEMPT RESTART USING STARTER. IF UNSUCCESSFUL,

1. ADVANCE PROP CONTROL LEVER TO FULL INCREASE RPM POSITION. 2. OPEN EMERGENCY UNFEATHER VALVE."

The placard lettering must be at least 1/8 inch in height and of a contrasting color.

Equivalent modifications maybe approved by the Chief, Engineering and Manufacturing Branch, FAA Great Lakes Region.

This amendment becomes effective January 29, 1979.

## 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/79-02-03/models.md
Every aircraft: https://openairdocs.org/ad/79-02-03/aircraft.md

## Related documents

- [STC SA1-52](https://openairdocs.org/stc/SA1-52): Installation of new propellers. Installation of emergency governor crossfeed system for unfeathering.. Hartzell Propeller, Inc, Named in the applicability

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