46-12-02 DOUGLAS: (Was Service Note 12 of AD-669-3.) Applies to DC3A Aircraft. \n\n\tInspection required immediately and every 100 hours thereafter on all aircraft which have beryllium copper engine mount to firewall attach fittings installed. \n\n\tInspect the engine mount to firewall attach fittings, P/N 5-81486-4 (with 4-power magnifying glass min.) in the fillet of the spot face for cracks or flaws in the material. If evidence of defects are found, replace with P/N 1042764. If cracks are not found, inspect every 100 hours until next engine change. P/N 5-81486-4 should be replaced with P/N 1042764 at engine change. \n\n\t(Douglas Service Bulletin No. 238 covers this same subject.)