47-42-14 DOUGLAS: (Was Mandatory Note 11 of AD-781-1.) Applies to DC-6 Serial Numbers 42854 to 42880, Inclusive; 42882 to 42884, Inclusive; 43000 and 43001. \n\nTo be accomplished not later than first blower overhaul after January 1, 1948. \n\nTo prevent bearing failures in the voltage regulator blowers, replace the bearings formerly packed with lubricant Z815 with new bearings containing lubricant Z801. \n\n(Douglas Service Bulletin DC-6 No. 43 describes the complete rework.)