80-12-09 GOVERNMENT AIRCRAFT FACTORIES (GAF): Amendment 39-3796. Applies to Models N22B (Serial Nos. N22B-5 and up) and N24A (Serial Nos. N24A-42 and up), certificated in all categories.
Compliance required as indicated. To prevent possible failure of rudder trim tab control, accomplish the following:
(a) Within the next 25 hours time in service after the effective date of the AD, unless already accomplished, visually inspect the rudder skin for loose rivets, and cracked intercostal flanges, and the rudder trim tab control rod for chafing, in accordance with GAF Nomad Alert Service Bulletin No. ANMD-55-11 (hereinafter referred to as the Service Bulletin) dated January 29, 1980, Part I and Part II, or an FAA-approved equivalent.
(1) If no cracks are found as a result of the inspection required by paragraph (a) of this AD, within the next 100 hours time in service after the effective date of this AD, unless already accomplished, perform the following modificationin accordance with Part III of the Service Bulletin:
(i) Replace rudder intercostal between W.L. 140.55 and W.L. 165.95 with an improved type or strengthen existing intercostal flanges.
(ii) Rework lower rudder intercostal lightening hole and angle to prevent chafing of rudder trim tab control rod.
(iii) Cut inspection hole in lower rib.
(2) If loose rivets or cracked flanges are found, before further flight, accomplish the modifications required by sub-paragraph (1)(i), (ii) and (iii) of this paragraph.
(b) Aircraft may be flown in accordance with FAR 21.197 and FAR 21.199 to a location where the modification can be performed.
(c) For purposes of complying with this AD, an FAA-approved equivalent must be approved by the Chief, Engineering and Manufacturing District Office, FAA, Pacific-Asia Region, Honolulu, Hawaii.
NOTE: All persons affected by this directive who have not already received the Service Bulletin from the manufacturer, may obtain copies upon request to the Government Aircraft Factories, 226 Lorimer Street, Port Melbourne 3207 Vic., Australia. These documents may also be examined at the FAA, Engineering and Manufacturing District Office, 300 Ala Moana Blvd., Room 7321, Honolulu, Hawaii 96850, or Rules Docket, Room 916, FAA, 800 Independence Avenue, S.W., Washington, D.C. 20591.
This amendment becomes effective June 23, 1980.