Airworthiness Directive · Amendment 39-19500 · Oxygen
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model 747-8 and 747-8F series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-8 and 747-8F series airplanes. This AD was prompted by a report that flightcrew oxygen masks did not function as designed during flight testing. This AD requires an inspection to determine if certain oxygen masks/regulators are installed, and replacement if necessary. We are issuing this AD to address the unsafe condition on these products.
For airplanes with an original certificate of airworthiness, or an original export certificate of airworthiness, issued on or before the effective date of this AD: Within 72 months after the effective date of this AD, inspect for oxygen mask/regulator part number (P/N) MLD20-626-1. A review of airplane maintenance records is acceptable in lieu of the part number inspection if the part number of the oxygen mask/regulator can be conclusively determined from that review. If any oxygen mask/regulator P/N MLD20-626-1 is found, within 72 months after the effective date of this AD, do the actions identified in paragraph (g)(1), (g)(2), or (g)(3) of this AD.
(1) Do all applicable actions identified as “RC” (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-35-2133, Revision 1, dated November 1, 2017, except as provided by paragraph (h) of this AD.
(2) Except as specified in paragraph (i)(3) of this AD: Remove oxygen mask/regulator P/N MLD20-626-1 and install any new or serviceable oxygen mask/regulator that is not P/N MLD20-626-1 and that is FAA approved for installation on the airplane.
Note 1 to paragraphs (g)(2) and (g)(3) of this AD: Guidance for the installation procedures can be found in Boeing Model 747 Aircraft Maintenance Manual (AMM) 35-11-18.
(3) Except as specified in paragraph (i)(3) of this AD: Remove the oxygen mask/regulator P/N MLD20-626-1 and the installed oxygen mask stowage box combination, and install any new or serviceable oxygen mask/regulator and stowage box combination that does not include oxygen mask/regulator P/N MLD20-626-1, and that is FAA approved for installation on the airplane.
Where Boeing Special Attention Service Bulletin 747-35-2133, Revision 1, dated November 1, 2017, refers to or specifies installing a new (or changed) part, for this AD, a new or serviceable (or changed) part is acceptable.
(1) For airplanes with an original certificate of airworthiness, or an original export certificate of airworthiness, issued on or before the effective date of this AD: As of the effective date of this AD, no person may install an oxygen mask/regulator P/N MLD20-626-1 on any airplane, except that prior to 72 months after the effective date of this AD, installation of P/N MLD20-626-1 is acceptable for unscheduled maintenance as a replacement only for another P/N MLD20-626-1, and only into a stowage box having P/N MXP806-1. If an oxygen mask/regulator having a part number other than P/N MLD20-626-1 is installed, it may not be replaced with P/N MLD20-626-1. For the purposes of this AD, unscheduled maintenance is defined as maintenance that was not planned for or scheduled in advance, such as changing a defective or unserviceable oxygen mask at dispatch.
(2) For airplanes with an original certificate of airworthiness or an original export certificate of airworthiness issued after the effective date of this AD: As of the effective date of this AD, no person may install oxygen mask/regulator P/N MLD20-626-1 on any airplane.
(3) For all airplanes: As of the effective date of this AD, no person may install oxygen mask/regulator P/N MLD20-726-1 in combination with any stowage box part number that is not P/N MXP806-7 on any airplane.
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.
Aircraft
