AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/GAF-N22/70 Amdt 1 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. GAF N22 and N24 Series Aeroplanes AD/GAF-N22/70 Amdt 2 Wing Strut Upper End Fitting 3/2003 Applicability: All Models Requirement: Inspect the attachment holes of the wing strut upper end fitting for cracks. Inspect in accordance with the eddy current method of Nomad Alert Service Bulletin ANMD- 57-12, Revision 2 dated 25 May 1999. Compliance: 1. For aircraft which have exceeded the time in service given in Table 2 of Nomad Alert Service Bulletin ANMD-57-12 Revision 2, inspect before further flight after 24 March 2003, unless inspected within the previous interval given in paragraph 3 below. 2. For aircraft which have exceeded the time in service in Table 1 of Nomad Alert Service Bulletin ANMD-57-12 Revision 2 but have not yet reached the Table 2 limits, inspect before 10 hours time in service after 24 March 2003, unless inspected within the previous interval given in paragraph 3 below. 3. Repeat the inspection at intervals not more than the following: 1. Models N24, N24A, N22S, N22C and N22F where the average flight duration is less than 45 minutes - 900 hours, b. Models N24, N24A, N22S, N22C and N22F where the average flight duration exceeds 45 minutes - 1200 hours, c. Model N22B where the average flight duration is less than 45 minutes - 1200 hours, d. Model N22B where the average flight duration exceeds 45 minutes - 1800 hours. This Amendment becomes effective on 20 March 2003. GAF N22 and N24 Series Aeroplanes AD/GAF-N22/70 Amdt 2 (Continued) Background: Fatigue tests on the wing strut upper end fitting have shown consistently early failures and rapid crack growth. Many aircraft have already exceeded the safe thresholds established by these tests, and are at risk of a fitting failure. Amendment 1 extends the repeat inspection interval based on the results of fractographic analysis. Further testing is being conducted. Amendment 2 updates the Requirement document for this AD to Revision 2 of SB ANMD-57-12 and adds the N24 model to the applicability. Amendment 1 of this Airworthiness Directive became effective on 17 August 1995. David Alan Villiers Delegate of the Civil Aviation Safety Authority 28 January 2003 The above AD is notified in the Commonwealth of Australia Gazette on 26 February 2003.