AD/B737/322 B/E Aerospace Oxygen Masks (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.

Boeing 737 Series Aeroplanes

AD/B737/322 B/E Aerospace Oxygen Masks 6/2008

Applicability:	Model 737-300, -400 and -500 series aeroplanes, as identified in Boeing Special Attention Service Bulletin (SB) 737-35-1099, dated 9 April 2007.
Requirement:	1.    Carry out a general visual inspection to determine the manufacturer and manufacture date of the oxygen masks in the passenger service units, the lavatory and cabin attendant box assemblies in accordance with the Accomplishment Instructions of Special Attention SB 737-35-1099.
2.    Accomplish the applicable corrective actions and other actions specified in Special Attention SB 737-35-1099, except where the service bulletin specifies repairing the oxygen mask assembly, replace it with a new or modified oxygen mask assembly having an improved flow indicator.
Note 1:  Special Attention SB 737-35-1099 refers to B/E Aerospace Service Bulletin 174080-35-01, dated 6 February 2006; and Revision 1, dated 1 May 2006; as additional sources of service information for modifying the oxygen mask assembly by replacing the flow indicator with an improved flow indicator.
Later revisions of the above SBs, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-06-24, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note 2:  FAA AD 2008-06-24 Amdt 39-15436 refers.
Compliance:	For Requirement 1 - Within 60 months after the effective date of this Directive.
For Requirement 2 - Before further flight after the Requirement 1 inspection.
This Airworthiness Directive becomes effective on 5 June 2008.

Background: The FAA has received a report that several passenger masks with broken in-line flow indicators were found following a mask deployment.  This Directive is issued to prevent the in-line flow indicators of the passenger oxygen masks from fracturing and separating, which could inhibit oxygen flow to the masks and consequently result in exposure of the passengers and cabin attendants to hypoxia following a depressurization event.

James Coyne
Delegate of the Civil Aviation Safety Authority

21 April 2008