COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes AD/TB20/8 Aileron Balance Weight Attachment 5/87 Applicability: All TB20 with S/Nos 275 to 700 except S/No 343, 638, 639, 643, 644, 645, 653, 664, 665, 672, 673, 683, 691, 693, 697, 698. Requirement: Action in accordance with Socata TB SB No 28. Compliance: At the next scheduled inspection for Maintenance Release issue after 7 May 1987 and thereafter at each scheduled inspection for Maintenance Release issue until modified. Background: The manufacturer reports instances of loosening of balance weights and skin cracking in the balance weight attachment area.