AD/B737/221 - Potable Water Pressure 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 39.1 (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.

Boeing 737 Series Aeroplanes

AD/B737/221 Potable Water Pressure Relief Valve 4/2004

Applicability: Model 737-100, -200, -200C, -300, -400, and -500 series aeroplanes; line numbers 1 through 2696 inclusive.

Requirement: 1. For those aeroplanes listed in the effectivity section of Boeing Service Bulletin (S/B)737-38-1029, Revision 1, dated August 19, 1993, on which the modification of the potable water pressurization system specified in the service bulletin has not been accomplished:

1. Modify the potable water pressurization system; in accordance with Boeing S/B 737-38-1029, dated June 6, 1991; or Revision 1 dated 19 August 1993 except for the following:

i Do not reinstall the existing pressure relief valve having part number (P/N) 520A6DB50.

ii Do not perform the leak test procedures specified in the referenced service bulletin.

b. Install a new pressure relief valve having P/N RV05-362, in accordance with Boeing S/B 737-38A1047, Revision 2, dated July 18, 2002 or earlier revisions.