AD/B737/160 - Hydraulic Shutoff Valves (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 39.1 (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.

Boeing 737 Series Aeroplanes

AD/B737/160 Hydraulic Shutoff Valves 9/2001

Applicability: All Boeing 737-100, -200, -300, -400, -500, -600, -700, -800 series aeroplanes equipped with hydraulic shutoff valves manufactured by Circle Seal Controls.

Note 1: Only motor operated hydraulic shutoff valves manufactured by Circle Seal Controls that are installed in the locations specified in applicable alert service bulletin (ASB) are subject to this Directive.

Requirement: 1. Perform an operational check of affected motor operated hydraulic shutoff valves in accordance with Boeing ASB 737-29A1073, Revision 3, dated 2 December 1999 or ASB 737-29A1081, dated 2 December 1999, as applicable.

If any malfunction of the valve is detected, prior to further flight, replace the valve with a new or serviceable Whittaker Controls or Circle Seal Controls valve in accordance with ASB 737-29A1073, Revision 3 or ASB 737-29A1081, as applicable.

2. Repeat the operational checks for the valves in accordance with ASB 737- 29A1073, Revision 3 or ASB 737-29A1081, as applicable, until the terminating action required by the Requirement 3 of this Directive is accomplished.