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/G164/5 Amdt 1 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. Schweizer (Grumman) G-164 (Ag-Cat) Series Aeroplanes AD/G164/5 Amdt 2 Elevator Torque Tubes - Inspection 10/2009 Applicability: All model G164 and G164A aircraft S/Nos 1 to 461. Requirement: Inspect the left and right hand elevator torque tubes for cracking adjacent to the inboard rib attachment welds, and also where the two 1/8 inch diameter blind rivets attach the right hand elevator leading edge skin cover to the torque tubes. Cracked tubes are to be repaired in accordance with Grumman Ag-Cat Service Bulletin (SB) No. 33. Compliance: At intervals not exceeding 100 hours time in service after 24 September 2009, or from time of compliance with the previous issue of this Directive, which ever occurs first. The repetitive inspections required by this Directive may be discontinued upon installation of the modification kit referenced in Grumman American Service Note No. 23 to modify the elevator horn assembly. This Amendment becomes effective on 24 September 2009. Background: This amendment includes a terminating action. David Villiers Delegate of the Civil Aviation Safety Authority 12 August 2009