79-23-02 BOEING: Amendment 39-3605. Applies to all Model 727 and 737 series airplanes with the "carry-all" interior. Compliance required as indicated. Accomplish the following: \n\n\tWithin the next 1,200 hours time-in-service or six (6) months after the effective date of this AD, whichever comes first, unless already accomplished, replace the straight orifice fittings on the Boeing part number 10-60513-18, -19, and -20 latch valves and manifold assemblies of the PSU with the redesigned barbed orifice fitting and O-ring in accordance with Boeing Service Bulletin 727-35-A18 dated July 6, 1979, or Boeing Service Bulletin 737-35-A1014 dated July 6, 1979, as applicable, and Puritan-Bennett Service Letter 210780-35-1 dated May 25, 1979, or later FAA-approved revisions. These passenger oxygen service unit manifolds are to be renumbered and functionally tested in accordance with the applicable service bulletin after the new barbed orifice fittings and O-rings have been installed. Thecompliance time prescribed above may be extended to 2,400 hours time-in-service or one (1) year after the effective date of this AD, whichever comes first, by limiting the operational altitude of the airplane to 25,000 feet. \n\tThe manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may also be examined at FAA, Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108. \n\n\tThis amendment becomes effective November 15, 1979.