47-02-03 MCDONNELL DOUGLAS: Amendment 39-3720. (Was Mandatory Note 11 of AD-762-7.) Applies to C-54 and DC-4 Aircraft. \n\n\tTo be accomplished not later than August 1, 1947. \n\n\tBecause of failures in service of the main 9" Douglas aluminum accumulator, it is necessary to replace it with at least one 7 1/2" steel accumulator, Bendix P/N 406920 or Vickers P/N AA14308B, or Vickers 10" accumulator Model AA-14310. \n\n\t(Douglas Service Bulletin DC-4 No. 9 and Addendum dated January 6, 1956 cover the same subject.) \n\n\tThis Amendment 39-3720 becomes effective March 27, 1980.