47-51-15 DOUGLAS: Applies to DC-6 Serial Numbers 42854 Through 42880; 42882 Through 42888; 42890; and 42891; 43000 Through 43003; 43005 Through 43009; 43055; and 43056. \n\nTo be accomplished not later than next No. 3 inspection. \n\nIn order to prevent malfunctioning of the brakes, the original Raybestos brake lining, P/N 9520535 must be replaced with Goodyear BL-56 lining, P/N 9521091. This new lining is identified with two yellow dots. \n\n(Douglas Service Bulletin DC-6 No. 1 covers this same subject.)