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/CESSNA 210/69 Amdt 1 and issues the following AD under subregulation 39.1 (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. Cessna 210 Series Aeroplanes AD/CESSNA 210/69 Amdt 2 Horizontal Stabilizer Front Spar 9/2004 Applicability: All models of Cessna 210 aircraft except 210R/T210R serial numbers 21064898 and subsequent. Requirement: Visually inspect the front and rear faces of horizontal stabilizer front spar assembly centre section for cracks around the cut-out in the front spar web. Refer to Figure 1 below. It should be noted that for models manufactured from 1969 onwards the horizontal stabiliser front spar will be of a three-layer design. This means that the centre laminate will effectively be hidden by the two outer laminates, making inspection of the centre laminate almost impossible. The centre laminate should be inspected as far as practicable without disassembly of the spar. Any cracks in the front spar web must be repaired before further flight, and a defect report must be submitted. Note 1: Access can be achieved by the removal of the fillet fairing. The front face of the front spar is easily seen. The rear face may be seen via a hole in the upper surface of the horizontal stabilizer using an inspection mirror and torch. Note 2: This inspection may require some experimenting with lights and mirrors to obtain some certainty in the results of the inspection. The inspection would be much easier to conduct with the use of a borescope. Compliance: a. For aircraft with less than 10000 hours time in service, inspect before exceeding 10000 hours total time in service, and thereafter at intervals not exceeding 110 hours time in service. b. For aircraft with 10000 or more hours time in service, inspect before18 March 2002, and thereafter at intervals not exceeding 110 hours time in service. This Amendment becomes effective on 2 September 2004. Background: Reports have been received of cracking of the horizontal stabilizer front spar on Australian registered Cessna 210s. Both front and rear spars must be serviceable for the horizontal stabilizer to carry ultimate load. The front spar forms part of the horizontal stabilizer's primary load path, and loss of strength in this area could be catastrophic. It should be noted that this Airworthiness Directive mandates an inspection requirement already stated in the manufacturer's maintenance data. Amendment 1 of this Airworthiness Directive is issued to highlight that later models have been manufactured with horizontal stabiliser spars containing three layers, making the centre laminate almost impossible to inspect. This amendment provides guidance on inspection of the three layer configuration. Compliance times remain unchanged. Amendment 2 of this Airworthiness Directive is issued to increase the recurrent compliance interval from 100 hours to 110 hours time in service to allow the inspections required by this Airworthiness Directive to be aligned with scheduled maintenance. The original issue of this Airworthiness Directive became effective on 6 March 2002. David Villiers Delegate of the Civil Aviation Safety Authority 23 July 2004 The above AD is notified in the Commonwealth of Australia Gazette on 11 August 2004.