COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Beechcraft 18 Series Aeroplanes AD/BEECH 18/4 Amdt 1 Horizontal Stabiliser Spar - Inspection NK Applicability: Model C-18S, D-18S and AT-11, not modified to Beech SB D-18-48. Requirement: 1. Inspect the horizontal stabiliser front spar and sub-spar for cracks at the points of attachment to the fuselage. 2. Remove the stabiliser and stabiliser lower skin panel and inspect for cracks in the front spar and sub-spar. 3. If cracking has occurred modify the stabiliser attachment in accordance with Beechcraft Service Bulletin No. D-18-48 or to the satisfaction of the Secretary before further flight. Compliance: For Para. 1 - At intervals not exceeding 10 hours time in service. For Para. 2 - At intervals not exceeding 500 hours time in service from the last inspection. Federal Register of Legislative Instruments F2006B03623