- Effective
- January 29, 1979
- Model
- G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B)
- Data sheet
- TCDSTC 654
- Registered aircraft
- 34 matched by model
- Product
- Aircraft · Small airplane
- Amendment
- 39-3400
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 20 KB | e2fefcb3…2fdfc09 | FAA DRS (API key needed) |
On this page
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 TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 34
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1939 | 2 |
|---|---|
| 1940 | 1 |
| 1942 | 4 |
| 1943 | 4 |
| 1944 | 3 |
| 1945 | 2 |
| 1946 | 5 |
| 1947 | 1 |
| 1951 | 1 |
| 1956 | 1 |
| 1958 | 1 |
| 1959 | 1 |
| 1962 | 1 |
7 with no year recorded