AD/SF340/86 - Hydraulic Pump Electrical Wiring (Cth)

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

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.

SAAB SF340 Series Aeroplanes

AD/SF340/86 Hydraulic Pump Electrical Wiring 13/2002

Applicability: SF340A series aeroplanes with serial numbers 004 to 028 inclusive.

Requirement: Modify the hydraulic pump electrical wiring circuit in accordance with Saab Aircraft Mandatory Service Bulletin (SB) SAAB 340-29-021 Revision 02 dated 2 October 2002.

Prior modification in accordance with either SB SAAB 340-29-021 dated 15 May 2001 or Revision 01 dated 3 April 2002 is considered acceptable terminating action for this Directive.

Note: LFV AD 1-179 R1 refers.

Compliance: Before 2 October 2003.

This Airwo rthiness Directive becomes effective on 26 December 2002.

Background: A high initial current flow to the hydraulic pump may cause a momentary power bus voltage drop. The voltage drop could cause the left hand electronic flight information system (LH EFIS) screens to blank when the hydraulic pump initially starts to supply hydraulic power to the landing gear and/or flaps. This temporary loss of information on the LH EFIS screens increases pilot workload.