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 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 525 Series Aeroplanes AD/CESSNA 525/4 Electric Pitch Trim Printed Circuit Board 10/2004 Applicability: Model 525 aeroplanes with the serial numbers 525- 0001, 525-0002, 525-0004 through 525-0359 inclusive. Requirement: 1. If not accomplished previously, replace the elevator trim printed circuit board (PCB) assembly part number (P/N) 6518351-3, 6518351-5 or 6518351-8 with a PCB assembly P/N 6518351-10 in accordance with the Accomplishment Instructions of Cessna Citation Service Bulletin SB525-27-17 dated 9 December 2003 by either: 1. Modifying the 6518351-8 trim PCB assembly to a 6518351-10 trim PCB assembly, or b. Replacing any 6518351-3 or 6518351-5 trim PCB assembly with a 6518351- 10 (EX) trim PCB assembly. 2. Remove any tie strap (P/N MS3367-1- 4 or equivalent P/N) on the AP SERVOS and PITCH TRIM circuit breakers. (Required by either AD/CESSNA 525/3 original issue or Amdt 1.) 3. Trim PCB assembly P/N 6518351-8, 6518351-3 or 6518351-5 may not be installed on any aeroplane as a replacement part. Note: FAA AD 2004-14-20 Amdt 39-13729 refers. Compliance: For Requirement 1 - Within the next two years after the effective date of this Directive or 300 hours time-in-service after the effective date of this Directive, whichever occurs first. For Requirement 2 - Before further flight after Requirement 1 is accomplished. For Requirement 3 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 30 September 2004. Cessna 525 Series Aeroplanes AD/CESSNA 525/4 (continued) Background: This Directive complements AD/CESSNA 525/3 Amdt 1, which required inhibition of the autopilot operation but allowed the installation of a trim PCB assembly P/N 6518351-8 as a temporary optional terminating action. This Directive requires the trim PCB assembly to be replaced providing a final terminating action for the autopilot inhibition. Gary J Carr Delegate of the Civil Aviation Safety Authority 19 August 2004 The above AD is notified in the Commonwealth of Australia Gazette on 8 September 2004.