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/PA-23/60 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. Piper PA-23 (Apache and Aztec) Series Aeroplanes AD/PA-23/60 Amdt 2 Stabilator Attachment Bolts - Inspection 2/2009 and Replacement Applicability: All models Piper PA-23-235 and PA-23-250 with serial numbers from 27-1 to 27-4654 if the four stabilator attachment bolts are not made of corrosion-resistant steel. Requirement: Remove the four stabilator attachment bolts and inspect for corrosion in accordance with Piper SL No. 667A. If corrosion is found, before further flight replace the bolt, nut and washer with unused parts of the same part numbers or equivalent. Alternatively, the bolts can be replaced by equivalent corrosion-resistant AN bolts. Note 1: Parts numbered 502329 and 502342 are corrosion-resistant bolts. Note 2: FAA AD 74-13-03 refers. Compliance: At intervals not exceeding three years or five hundred hours time in service, whichever occurs first. Alternatively, the bolts can be replaced by equivalent corrosion-resistant AN bolts. Note 3: Compliance with this AD at amendment 1 constitutes compliance with this amendment. This Amendment becomes effective on 12 February 2009. Background: The original issue of this AD in January 1974 specified replacement of stabilator attachment bolts within 100 hours after 31 January 1974, based on Piper SL No. 667. Amendment 1 in March 1974 specified inspection at 3 monthly intervals as an alternative to replacement, due to difficulties with supply of suitable corrosion-resistant bolts. In March 1974 Piper issued SL No. 667A to authorise, as an alternative to corrosion-resistant bolts, new steel alloy bolts with repetitive inspections at intervals not to exceed 500 hours in service. In June 1974 the FAA issued AD 74-13-03 (amdt 39-1872) specifying inspection at intervals not to exceed 3 years or 500 hours, whichever occurred first, as an alternative to replacement. AD 74-13-03 nominated Piper SL No. 667A. Amendment 2 is raised to align the inspection interval with FAA AD 74-13-03; to identify the FAA AD on which AD/PA-23/60 is now based; and to add Piper SL No. 667A as the instructions for inspecting steel alloy bolts. David Punshon Delegate of the Civil Aviation Safety Authority 11 December 2008