Airworthiness Directive · Amendment 39-19472 · Crew oxygen system
Zodiac Aerotechnics Oxygen Mask Regulators
This AD applies to Zodiac Aerotechnics (Zodiac) MC10 series crew oxygen mask regulators fitted with an inflatable harness assembly, part number (P/N) MXH20-1 or MXH21-1.
We are adopting a new airworthiness directive (AD) for certain Zodiac Aerotechnics (Zodiac) oxygen mask regulators. This AD was prompted by reports that certain silicon harness inflation hoses installed on certain flight crew quick donning mask harnesses have shown an unusually high premature rupture rate. This AD requires inspection and replacement of certain oxygen mask regulator harness inflation hoses. We are issuing this AD to address the unsafe condition on these products.
(1) Within 36 months after the effective date of this AD, determine the date of manufacturing (DMF) code of each inflatable harness assembly, P/N MXH20-1 and P/N MXH21-1, fitted to a flight crew oxygen mask regulator, having a P/N listed in Planning Information, paragraph 1.A.(1), of Zodiac Aerospace Service Bulletin (SB) MC10-35-274, Revision 02, dated June 25, 2014. A review of airplane delivery or maintenance records is acceptable to make the determination as specified in this paragraph, provided those records can be relied upon for that purpose, and the DMF of the inflatable harness assembly, P/N MXH20-1 or P/N MXH21-1, as applicable, can be conclusively identified from that review.
(2) If during the review required by paragraph (g)(1) of this AD, the DMF code of the inflatable harness assembly, P/N MXH20-1 or P/N MXH21-1, is found to be between 0850-S and 1051-S (inclusive): Within 36 months after the effective date of this AD, replace the harness inflation hose, P/N 445186 or P/N 445952, as applicable, with a part eligible for installation, or remove the inflatable harness assembly from the mask regulator and replace it with an inflatable harness assembly eligible for installation.
(3) An oxygen mask regulator equipped with an inflatable harness assembly, P/N MXH20-1 or P/N MXH21-1, having a DMF code of November 2008 (0845-S or 08/45-S) or earlier, and those with a DMF code of January 2011 (1101-S or 11/01-S) or later, are excluded from the requirements of this AD, provided it can be demonstrated that neither the inflatable harness assembly, nor the harness inflation hose, P/N 445186 or P/N 445952, as applicable, was replaced on that mask. An oxygen mask regulator with an inflatable harness assembly, P/N MXH20-1 or P/N MXH21-1, and with an inflatatable harness assembly with a metal bushing that has been marked with an “I” is also excluded from the requirements of this AD. A review of airplane delivery or maintenance records is acceptable to make the determination, provided those records can be relied upon for that purpose.
After the effective date of this AD, do not install on any airplane a flight crew oxygen mask regulator with a P/N listed in Planning Information, paragraph 1.A.(1), of Zodiac SB MC10-35-274, Revision 02, dated June 25, 2014, unless it meets the definition of a part eligible for installation in paragraph (i) of this AD.
(1) After the effective date of this AD, a part eligible for installation is a crew oxygen mask regulator with:
(i) A P/N identified in Planning Information, paragraph 1.A.(1), of Zodiac Aerospace SB MC10-35-274, Revision 02, dated June 25, 2014, provided it has been determined that a P/N MXH20-1 or P/N MXH21-1 inflatable harness installed on that crew oxygen mask regulator has been inspected, and re-marked with an “I” as required by Material Information, paragraph 2.E. of Zodiac Aerospace SB MC10-35-274, Revision 02, dated June 25, 2014; or
(ii) a P/N identified in Planning Information, paragraph 1.A.(1), of Zodiac Aerospace SB MC10-35-274, Revision 02, dated June 25, 2014, provided it has been determined that an inflatable harness, P/N MXH21-31, is installed.
(2) [Reserved]
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Appliances and equipment
