48-02-02 DOUGLAS: Applies to C-54 and DC-4 Aircraft With Wilcolator Fire Detectors Installed in the Engine Power Section of the Nacelle. \n\nCompliance required by next engine change. \n\nRevise the method of attachment of the A-4981 Wilcolator fire detectors located on the cowl flap support wing in zone 1 by clamping the detector to its mounting plate with a retainer strip of 0.062-thickness low carbon steel sheet, cadmium plated, secured with the same screws which attach the detector to the support box. Failure of the supports is caused by vibration during engine operation. \n\n(Douglas Service Bulletin DC-4 No. 75 covers this same subject.)