AD/Do 328/59 Hydraulic Pressure Dump and Relief Valve (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.

Dornier 328 Series Aeroplanes

AD/DO 328/59 Hydraulic Pressure Dump and Relief Valve 6/2006

Applicability:

Dornier 328-100 aeroplanes Serial Numbers 3005 through 3095 inclusive.

Requirement:

Unless previously accomplished replace the pressure dump and relief valve Part Number (P/N) ZHV29-1 with valve P/N ZHV29-2.

Note 1:  LBA AD 97-072 dated 27 March 1997refers.

Note 2:  Dornier 328 Service Bulletin No. 328-29-205 pertains to this subject.

Compliance:

Within 30 days after the effective date of this AD.

This Airworthiness Directive becomes effective on 8 June 2006.

Background:

The pressure dump and relief valve may have a thin section in the housing and may have been overtorqued during manufacture.  This may lead to hydraulic leakage from the valve and loss of the hydraulic system from the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

28 April 2006