AIRWORTHINESS DIRECTIVE On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/GA8/5 Amdt 3 and issues the following AD under subregulation 39.001(1) of CASR 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. Gippsland Aeronautics GA8 Series Aeroplanes AD/GA8/5 Amdt 4 Horizontal Stabiliser Inspection 10/2010 Applicability: All GA8 aircraft serial numbers GA8-00-004 and above, and GA8-TC 320 variant, all serial numbers. Requirement: Accomplish the requirements of Gippsland Aeronautics mandatory service bulletin SB-GA8-2002-02, Issue 6, dated 21 April 2010. Accomplish the requirements (Instructions 1 to 5) in accordance with the applicability matrix in Table 1 of the service bulletin. Note: In the service bulletin, Table 1, NA = normally aspirated, TC=turbocharged. Compliance: As per requirement document. This Amendment becomes effective on 19 May 2010. Background: Inspection of a high time aircraft has revealed cracks in the Horizontal Stabiliser rear spar splice plate and inboard main ribs around the area of the Horizontal Stabiliser rear pivot attachment. Additionally, failure of some attach bolts in service may be due to improper assembly. This amendment is issued to include an applicability matrix (Table 1, page 2) in the compliance section of the service bulletin for improved clarity. The previous amendment included reference to the GA8-TC 320 variant in the applicability section. Amendment 2 was issued because the requirement document now contains an inspection for cracking in horizontal stabilisers which have load transferring fittings installed. Previous amendments of this AD listed the AD requirements in full. Due to the extensive use of diagrams and photographs, it is no longer appropriate or practical to write the requirements of the service bulletin out in full in this AD. All requirements, accomplishment instructions and illustrations are contained in the service bulletin. The original issue of this AD became effective on 15 February 2007. The previous amendment became effective 13 April 2010. Mike Higgins Delegate of the Civil Aviation Safety Authority 11 May 2010