48-02-06 DOUGLAS: Applies to DC-6 Serial Numbers 42854 Through 42896; 43000 Through 43018; 43025; 43055 Through 43057; 43062 Through 43064; and 43105. \n\n\tCompliance required by March 1, 1948. \n\n\tAs a fire protection measure, close off the dead air space between the upper and lower wing surfaces within the engine nacelle by installing cover plates over the open access hole in the lower surface of the wing in the right and left inboard nacelles between center and front spars and between Stations 130 and 167. \n\n\t(Douglas Service Bulletin DC-6 No. 92 covers this same subject.)