AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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. Consolidated Aeronautics, Colonial and LA-4 Series Aeroplanes AD/LA-4/27 Wing Spar Doublers and Spar Cap Angles 13/2002 DM Applicability: Affected aircraft with wing spar part numbers incorporated, as specified below: Model Serial Numbers Model LA-4 Serial numbers 246 through 421, 423 through 429, 445, and 446. Model LA-4A Serial numbers 244 and 245. Model LA-4P Serial number 121. Model LA-4-200 Serial numbers 422, 430 through 444, 446 and subsequent. Model 250 Serial numbers 1 through 232. Wing Spar Parts Part Numbers Upper Spar Cap Angles 2-1610-015 and 2-1610-016 Lower Spar Cap Angles 2-1610-075 and 2-1610-076 Upper Spar Doublers 2-1610-061 and 2-1610-081 and 2-1610-065 Lower Spar Doublers 2-1610-063 and 2-1610-083 Requirement: 1. Inspect the wing spar doublers and spar cap angles for cracks from the root end to the outboard of the wing spar attachment fittings, as follows: 1. From inside the wheel well, clean the upper and lower wing spar doublers and adjoining structure to the paint. Use a detergent or mineral-based solvent. 2. Use a strong light source and a 3x magnifying glass to inspect the exposed areas of the upper and lower spar doublers and adjoining structure for cracks. Use a mirror to inspect the exposed edge of the spar cap angle behind the doubler. Consolidated Aeronautics, Colonial and LA-4 Series Aeroplanes AD/LA-4/27 (Continued) 2. Replace any doubler or angle found cracked during the inspections required by Requirement 1. Replace with new parts that incorporate the same part numbers or FAA-approved equivalent part numbers. Note: FAA AD 2002-21-05 Amdt 39-12911 refers. Compliance: Upon accumulating 25 hours time in service after incorporating Modification B-79 (as required by AD/LA-4/26 Amdt 1), or within 10 hours time in service after 13 November 2002, whichever occurs later; unless already accomplished. This Airworthiness Directive becomes effective on 13 November 2002. Background: The FAA received a report of a crack at the most outboard wing attachment fitting hole on one of the affected aircraft with Modification Kit B-79 incorporated. The actions required by this Directive are intended prevent wing spar failure caused by cracks in the wing spar doublers or angles. David Alan Villiers Delegate of the Civil Aviation Safety Authority 7 November 2002 The above AD is notified in the Commonwealth of Australia Gazette on 13 November 2002.