COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AMD Falcon 50 and 900 Series Aeroplanes AD/AMD 50/10 Amdt 1 Overhead Panel Wiring Harness 7/96 Applicability: All Falcon 900 series aircraft. Requirement: 1. Check the condition and correct run of the wiring harness connected to the overhead panel in accordance with Dassault Aviation Alert Service Bulletin F.900- A172 dated 11 October 1995. If the cables are found to be damaged then carry out Dassault Aviation Service Bulletin F.900-173 dated 11 October 1995. 2. Install insulating protectors on both ceiling headliner grounding modules in accordance with Dassault Aviation Service Bulletin F900-174 dated 3 April 1996. Note: DGAC Airworthiness Directive 95-204-016(B)R1 dated 27 March 1996 refers. Compliance: For Requirement 1 - This compliance remains unchanged as `Unless already accomplished, prior to 1 February 1996'. For Requirement 2 - Either prior to 30 April 1997 or prior to the accumulation of 600 hours time in service after 20 June 1996, whichever occurs first. Background: During start, a Falcon 900 crew was unable to connect battery No 1: every attempt to connect it led to the tripping of battery circuit breaker (19P1) on the GPA main electrical box. Investigations revealed that a wire from the overhead panel NORM/EXT.POWER selector (3PE) was interfering with one of the two grounding modules located behind the panel. This caused a wire to short to ground. This amendment introduces measures designed to prevent chaffing caused by interference between the overhead panel wiring harness and the grounding modules. The original issue of this Airworthiness Directive became effective on 1 February 1996.