COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Mooney M20 Series Aeroplanes AD/M20/38 Fuselage Tubular Structure - Modification 2/80 Applicability: All model M20K with S/Nos. 25-0001 to 25-0247. Document: Mooney SB No. M20-220. Compliance: Before 1 July 1980. Background: The manufacturer advises of the possibility of the lower fuselage longeron buckling under severe positive gust conditions.