AD/SF340/104 Fuel Tank Conduits Wiring Protection (Cth)

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 39.001(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.

SAAB SF340 Series Aeroplanes

AD/SF340/104 Fuel Tank Conduits Wiring Protection 11/2007

Applicability:

Model SF340A and 340B aircraft, all serial numbers.

Requirement:

Unless previously accomplished, perform Modifications 3164 (Right Hand Wing) and 3165 (Left Hand Wing) in accordance with SAAB Service Bulletin 340-28-026, dated 5 July 2007 or late EASA approved revision.  The modifications include:

-      Removal of the fuel pumps 5QM and 6QM, the fuel Switches 31EB, 32EB, 9QA, 10QA, 11QA and 12QA and the refuel shutoff valves 15QA and 16QA;

-      Inspection of the wiring to the fuel pumps, fuel level switches and the refuel shut off valves;

-      Twisting of the fuel pump wiring, fuel level switches wiring and refuel shutoff valves wiring;

-      Installation of a shrinkable tube to the fuel pump wiring, fuel level switches wiring and refuel shutoff valve wiring;

-      Installation of fuel pumps, the fuel level switches and the refuel shutoff valves; and

-      Operational and Functional test of the fuel Measuring/Indicating system.

Note:  EASA AD 2007-0248 refers.

Compliance:

Within 72 months after the effective date of this Directive.

This Airworthiness Directive becomes effective on 25 October 2007.

Background:

Subsequent to accidents involving Fuel Tank System explosions in flight (Boeing 747-131 flight TWA800) and on ground, the United States Federal Aviation Administration (FAA) published Special Federal Aviation Regulation 88 (SFAR88) in June 2001.

In their Letters referenced 04/00/02/07/01-L296 dated 4 March 2002 and 04/00/02/07/03-L024, dated 3 February 2003, the European Joint Airworthiness Authority (JAA) recommended the application of a similar regulation to the National Aviation Authorities (NAA).

Under this regulation, all holders of type certificates for passenger transport aircraft with either a passenger capacity of 30 or more, or a payload capacity of 7 500 pounds (3 402 kg) or more, which have received their certification since 1 January 1958, are required to conduct a design review against explosion risks.

As a consequence of the design review mentioned above, this Airworthiness Directive requires a modification to install extra protection of wiring installed in fuel tank conduits.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

14 September 2007