74-15-04 MCDONNELL DOUGLAS: Amendment 39-1900. Applies to Douglas Model DC-10 Series airplanes, certificated in all categories, incorporating Weber Aircraft seats, Part Number 818472-401, 402, 403, 411, 412, 413, 415, 416, 417, 418, 419, 4011, 4021, and 4031 and 819900-401, 402, and 403. \n\n\tCompliance required as indicated. \n\n\tTo prevent possible failures of the oxygen doors, accomplish the following: \n\n\t(a)\tWithin 300 hours' additional time in service, and at intervals not to exceed 300 hours' time in service, until (b), below, is accomplished, perform a visual inspection of all oxygen doors to verify that upholstery fabric does not obstruct the oxygen door, should door opening become necessary. If such obstruction is observed, correct before further flight. \n\n\t(b)\tWithin 1,500 hours' additional time in service, unless already accomplished, install shrouds around the first-class seat back oxygen doors in accordance with Weber Aircraft Service Bulletins No. 25-314, dated November 1, 1973, and No. 25-330, dated May 15, 1974, or later FAA-approved revisions. \n\n\t(c)\tEquivalent installations may be approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t(d)\tAircraft may be flown to a base for the performance of that maintenance required by this AD per FAR's 21.197 and 21.199. \n\n\tNOTE: For the requirements regarding the listing of compliance and method of compliance with this AD in the airplane's permanent maintenance record, see FAR 91.173. \n\n\tThis amendment becomes effective August 26, 1974.