COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F50 (F27 Mk 50) Series Aeroplanes AD/F50/66 Lavatory Pump and Filter Assembly Electrical Grounding 12/94 Applicability: Model F27 Mk50 aircraft serial numbers 20103 through 20226 inclusive, 20270 through 20292 inclusive, 20296 through 20304 inclusive, 20306, 20307, 20309, 20310 and 20312. Requirement: Action in accordance with accomplishment instructions of Fokker Service Bulletin F50-25-046 Revision 1 dated 5 August 1994. Note: RLD AD 94-129 (A) dated 31 August 1994 refers. Compliance: Prior to 10 May 1995. Background: The Lavatory Pump and Filter Assembly is driven by a 115V AC motor and the metal toilet bowl is connected to the housing of the electric motor. However, the motor housing is not connected to an effective ground. Consequently, should a failure of the electric motor occur, the toilet bowl may carry a high voltage. This Directive requires the installation of an electrical ground connection.