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/AMD 50/47 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. AMD Falcon 50 and 900 Series Aeroplanes AD/AMD 50/47 Amdt 1 Crew and Passenger Oxygen Lines 9/2009 Applicability: Falcon 900EX aeroplanes with serial numbers listed in Table 1. Table 1 – List of Serial Numbers 120 129 139 147 163 178 121 132 140 151 165 182 122 134 141 153 168 183 123 135 142 155 169 194 125 136 143 157 170 196 126 137 144 158 172 197 127 138 145 159 174 199 206 Requirement: 1. Inspect the oxygen lines in accordance with Part 1 of the accomplishment instructions of Dassault Aviation Service Bulletin (SB) F900EX-347 Revision 1 dated 18 May 2009. 2. If any interference or damage is found during the Requirement 1 inspection, replace the oxygen lines and install improved brackets in accordance with Part 2 of the accomplishment instructions of SB F900EX-347 Revision 1. 3. Replace the oxygen line support assemblies in accordance with Part 2 of the accomplishment instructions of SB F900EX-347 Revision 1. Inspections and corrective actions accomplished before the effective date of this Amendment, in accordance with the accomplishment instructions of SB F900EX-347 initial issue dated 19 March 2009, satisfy the requirements of this Amendment. Later revisions of the above SB approved by the European Aviation Safety Agency (EASA) are acceptable for compliance with the requirements of this Amendment. Note: EASA AD 2009-0126 refers. Compliance: For Requirement 1 - Within two months after the effective date of this Amendment. For Requirement 2 - Before further flight following the Requirement 1 check. For Requirement 3 - Within 72 months after the effective date of this Amendment. This Amendment becomes effective on 27 August 2009. Background: A quality control inspection performed during completion of one Falcon 900EX aeroplane has shown that the crew and passenger Right-Hand (RH) oxygen lines may both interfere with the frame 8 of the aeroplane structure. A subsequent design review of the oxygen lines routing has confirmed that, on certain aeroplanes, equipped with a 115 cu-ft oxygen cylinder in the RH mid-cabin, may have been installed in such a way as to cause interference with the structure. This condition, if not corrected, could lead to an oxygen leak. As a result, the original issue of this Directive required inspection of the oxygen lines, replacement of any damaged lines and modification of their support assembly. This Amendment, whilst continuing the requirements of the original issue, requires compliance in accordance with revision 1 of the service bulletin and revises the applicability. The original issue of this Directive became effective on 30 July 2009. James Coyne Delegate of the Civil Aviation Safety Authority 30 June 2009