AD/SF340/77 - Refuel/Defuel Panel Electrical Arcing (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

SAAB SF340 Series Aeroplanes

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 CAR 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.

AD/SF340/77 Refuel/Defuel Panel Electrical Arcing 5/2000

Applicability: Model SF340A aeroplanes, serial numbers (S/N) 004 through 159 inclusive and Model 340B aeroplanes, S/N 160 through 459 inclusive, with Refuel/Defuel Panel Part Number 7239160-505 installed.

Requirement: Inspect the Fuel/Defuel Panel for evidence of moisture ingress and electrical arcing in accordance with SAAB Aircraft AB Mandatory Service Bulletin (SB) SAAB 340-28- 022 dated 25 February 2000. If evidence of moisture ingress or arcing is found carry out the corrective actions specified in SB SAAB 340-28-022, if no evidence is found seal the appropriate areas as specified in the service bulletin.

Note: LFV AD 1-156 refers.

Compliance: Within six months from the effective date of this Directive.

This Airworthiness Directive becomes effective on 18 May 2000.

Background: The Swedish Civil Aviation Administration has advised that electrical short circuits and arcing can occur at the illuminated placard connector at the wing Fuel/Defuel Panel. These shorts are caused by fluid ingress through the mounting hole. The illuminated placard is only supplied with 28VDC power when the Refuel/Defuel Panel switch is selected to on, this occurs when the aircraft is on the ground during refuelling or de-fuelling. Electrical arcing at the Refuel/Defuel Panel illuminated placard connector offers a potential ignition source for fuel vapours during refuelling or de-fuelling.