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. Pilatus PC-12 Series Aeroplanes AD/PC-12/42 Passenger Oxygen System Pipes 8/2004 Applicability: Model PC-12 and PC-12/45 aeroplanes with the following Manufacturer Serial Numbers (MSN), fitted with an executive interior and a six, seven or eight-seat oxygen system installed: 124 417 thru 424 441 492 166 427 443 thru 444 494 thru 496 401 429 thru 430 446 thru 465 498 thru 516 405 432 thru 433 468 thru 470 518 thru 522 407 435 thru 437 472 thru 475 524 411 thru 414 439 478 thru 490 Requirement: Accomplish the following, as applicable to each aircraft configuration, in accordance with Pilatus PC-12 Service Bulletin 35-004 dated 19 December 2003: 1. Remove and discard the forward oxygen pipe part number (P/N) 535.21.12.076 and install new forward oxygen pipe P/N 535.21.12.125. 2. Carry out the following inspections: 1. Inspect the overhead panel for damage. If damage is found; contact PILATUS for repair procedures. b. Inspect the interior-lighting power-supply units for damage. c. For aeroplanes with the eight-seat oxygen system installed; inspect the aft oxygen pipe P/N 535.21.12.054 for damage. 3. Carry out the following Modifications: 1. For aeroplanes with the TCAS antenna and the eight-seat oxygen system installed; modify the TCAS antenna cable routing in accordance with paragraph (3) (E) and (Fig. 2) of SB No. 35-004. b. For aeroplanes with the eight-seat oxygen system installed; modify the attachment of the aft oxygen pipe routing in accordance with paragraph (3) (F) and (Fig. 1) of SB No. 35-004. Pilatus PC-12 Series Aeroplanes AD/PC-12/42 (continued) 4. If damaged interior-lighting power-supply unit(s) is found during the Requirement 2.b. inspection, replace the damaged unit (s). 5. If a damaged aft oxygen pipe is found during the Requirement 2.c. inspection, replace the pipe. Note: Swiss FOCA AD HB-2004-182 refers. Compliance: For Requirements 1, 2 and 3: Aircraft Total Hours Time in Service (TIS) Compliance Less than 1500 hours TIS At the next annual inspection after the effective date of this Directive, but not later than 31 December 2004 Greater than 1500 hrs TIS At the next 100 hrs inspection after the effective date of this Directive, but not later than 31 December 2004 For Requirements 4 and 5 - Prior to further flight after the inspection. This Airworthiness Directive becomes effective on 5 August 2004. Background: The Swiss Federal Office for Civil Aviation (FOCA) has advised that it is possible for chaffing damage to occur which could result in the leakage of the passenger oxygen pipe assembly. The chaffing is due insufficient clearance between the passenger oxygen pipe assemblies and some of the cabin lighting components in the headliner in aeroplanes with executive interiors. This Directive requires inspection of the installation for damage, modification of the pipe assembly to increase the clearance distance between the oxygen pipes and lighting components, and replacement of parts and/or components as required. James Coyne Delegate of the Civil Aviation Safety Authority 23 June 2004 The above AD is notified in the Commonwealth of Australia Gazette on 14 July 2004.