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.