COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Douglas DC4 Series Aeroplanes AD/DC4/29 Fire Detector Guard - Installation NK Applicability: All models. Requirement: Install a guard over each Wilcolator fire detector in the baggage compartment which will adequately protect the unit from vertical and horizontal damage, but which will not impair the effectiveness of its heat detection. Note: Figure 1 of this Order provides details of an approved type of guard. or ANO 105.1.16.2.5.28.