AD 80-11-10 ACTIVE

80-11-10 GOVERNMENT AIRCRAFT FACTORIES (GAF): Amendment 39-3781. Applies to Models N22B and N24A airplanes, certificated in all categories.

Unless already accomplished, compliance is required within 25 hours time in service after the effective date of this AD. However, airplanes may be flown in accordance with FAR 21.197 and 21.199 to a base where the work can be performed.

(1) Applies to all Model N22B airplanes S/N 5 and up and all Model N24A airplanes S/N 42 and up, delivered or in operation prior to, or on, June 22, 1978. To prevent leakage of hot air check valve, P/N I/N-74-334, which could damage surrounding components, inspect, and repair as necessary, hot air check valve P/N I/N-74-334, in accordance with Accomplishment Instructions of GAF Alert Service Bulletin AN 22-74-1, Revision 1, dated June 30, 1978, or an FAA-approved equivalent.

(2) Applies to all Model N22B airplanes S/N 5 and up, and all Model N24A airplanes, S/N 42 and up, which have not incorporated Nomad modification N301. To prevent possible disconnection or jamming of pilots' or copilots' control wheel assembly, which could result in loss of control of the airplane, remove control wheel retaining pin and replace with a new bolt in accordance with the Accomplishment Instructions of GAF Alert Service Bulletin AN 22-27-8, Revision 1, dated June 30, 1978, or an FAA-approved equivalent.

(3) Applies to all Model N22B airplanes S/N 5 and up, and Model N24A airplanes S/N 42 and up, delivered from the factory prior to July 4, 1978. To prevent possible dislodging of structural bolts securing the wing center section spar support brackets to the fuselage, which could result in loss of structural integrity of the airplane, inspect wing center section spar support bracket for loose attachments, and replace loose nuts, in accordance with the Accomplishment Instructions of GAF Alert Service Bulletin ANMD-53-2, Revision 1, dated July 5, 1978, or an FAA-approved equivalent.

(4)Applies to all Model N22B airplanes S/N 5 and up, and all Model N24A airplanes S/N 42 and up, which have not incorporated Nomad modification N290. To prevent possible interference and jamming of the rudder pedals with the pedal guards, which could impair control of the airplane, remove and repair rudder pedal guards in accordance with the Accomplishment Instructions of GAF Alert Service Bulletin ANMD-53-3, dated July 10, 1978, or an FAA- approved equivalent.

(5) Applies to Model N22B airplanes S/N 6, 7, 11, 12, 13, 15, and 16. To prevent reduction of the flutter speed reserves as a result of excessive wear and backlash in the rudder tab operating system, which could result in loss of control of the airplane, remove rudder assembly, install steel mass balance arm and rework rudder and trim tab in accordance with the Accomplishment Instructions of GAF Alert Service Bulletin NMD-27-3, Revision 1, dated June 8, 1979, or an FAA-approved equivalent.

(6) Applies to all Model N22B airplanes S/N 5 and up, and all Model N24A airplanes S/N 42 and up. To prevent excessive vibration of the horizontal stabilizer trim tab and prevent subsequent structural damage to the empennage, which could result in loss of control of the airplane, inspect the horizontal stabilizer trim tab, and empennage, and modify stub fin in accordance with the Accomplishment Instructions of GAF Alert Service Bulletin ANMD-55-5, Revision 2, dated September 3, 1979, or an FAA-approved equivalent.

(7) Applies to all Model N22B airplanes S/N 5 and up, and all Model N24A airplanes, S/N 42 and up. To detect possible damage to the horizontal stabilizer control rod, visually inspect components in the horizontal stabilizer control system for wind gust damage, and replace as necessary, in accordance with the Accomplishment Instructions of GAF Alert Service Bulletin ANMD-27-12, Revision 1, dated October 30, 1979, or an FAA-approved equivalent.

For the purposes of this amendment, the FAA-approvedequivalent specified in paragraphs (1) through (7) of this AD must be approved by the Chief, Engineering and Manufacturing District Office, FAA, Pacific-Asia Region, Honolulu, Hawaii.

All persons affected by this directive who have not already received these documents 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, Pacific-Asia Region, 300 Ala Moana Blvd., Room 7321, Honolulu, Hawaii 96850, and at FAA Headquarters, 800 Independence Ave., S.W.., Washington, D.C. 20591. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its Headquarters in Washington, D.C., and at the Pacific-Asia Region in Honolulu, Hawaii.

This amendment becomes effective June 5, 1980.