COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Eurocopter BO 105 Series Helicopters AD/BO 105/8 Tail Boom Skin 3/87 Applicability: All models. Requirement: Action in accordance with MBB BO 105 Alert Bulletin No 15 Revision 1. Compliance: As detailed in the Requirement Document. Background: Cracked tail boom skins have been found in service. LBA Directive 76-317/2 MBB refers.