COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DH114 (Heron) Series Aeroplanes AD/DH114/43 Amdt 2 Applicability: All models. Centre Section Main Spar Top and NK Bottom Boom Joint - Inspection Requirement: 1 Inspect the Centre Section Main Spar Top Boom in accordance with Hawker Siddeley TNS Heron (114) No. F.19 Appendix 1, or in accordance with a technique approved by the Secretary. Technique ATG/NDI/US/1 constitutes such an approved technique. 2. Inspect the Centre Section Main Spar Bottom Boom of those aircraft without Mod. 492 embodied, in accordance with Hawker Siddeley TNS Heron (114) No. F.20, Appendix 1, or in accordance with a technique approved by the Secretary. Technique ATG/NDI/US/1 constitutes such an approved technique. Note: Where crack indications are found the Airworthiness Branch, Central Office, is to be notified before further flight. Compliance: Inspect at intervals in accordance with Hawker Siddeley TNS Heron (114) No. F.19 and F.20 as applicable.