78-25-09 MCDONNELL DOUGLAS: Amendment 39-3372. Applies to DC-10-10, -10F, -30, -30F, and -40 airplanes certificated in all categories which have Universal Oil Products Company Model 900-400-C3C seats through Serial No. 3860, installed. \n\n\tCompliance required within the next 30 days after the effective date of this AD, unless already accomplished. \n\n\tTo assure that the seatback tray table retention clip cannot be rotated to a position in which it prevents automatic deployment of oxygen masks during depressurization, accomplish the following: \n\n\t(a)\tModify the Universal Oil Products Company Model 900-400-C3C seat through Serial No. 3860, in accordance with Universal Oil Products Service Bulletin No. 25-494, original issue dated September 18, 1978. \n\n\t(b)\tEquivalent modification may be used when approved by the Chief, Aircraft Engineering Division, FAA, Western Region. \n\n\t(c)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanesto a base for the accomplishment of the modifications required by this AD. \n\n\tThis amendment becomes effective December 22, 1978.