COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DH114 (Heron) Series Aeroplanes AD/DH114/48 Aileron Mass Balance Weight Assembly 7/87 Applicability: All models. Requirement: 1. Action in accordance with British Aerospace TNS W19 Issue 1, or 2. Inspect in accordance with a scheme approved by the Secretary. Compliance: Unless already accomplished; 1. In accordance with the Requirement Document, but no later than 31 August 1987. 2. At the next inspection for Maintenance Release issue after 30 June 1987 but no later than 31 August 1987. Background: A case has been reported of severe internal corrosion. Loss or failure of the balance assembly may cause aileron flutter or severe handling problems.