COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DH 104 (Dove) Series Aeroplanes AD/DH 104/37 Aileron Mass Balance Weight Assembly 7/87 DM Applicability: All models. Requirement: Action in accordance with British Aerospace TNS 245 Issue 1. Compliance: 1. Carry out the visual inspection within 14 days after 30 April 1987 and, 2. If no corrosion is evident visually, carry out the radiographic inspection within 50 hours time in service after 30 April 1987 but no later than 31 July 1987. Background: A case has been reported on a Heron aircraft of severe internal corrosion. Loss or failure of the balance assembly may cause aileron flutter or severe handling problems.