COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SD3-60 Series Aeroplanes AD/SD3-60/18 Take-Off Trim Range 12/86 DM Applicability: All Shorts SD3-60, fitted with Pratt and Whitney PT6A-65R engines, and Shorts SD3-60 with serial numbers SH3601 to SH3685, fitted with Pratt and Whitney PT6A- 65AR engines. Requirement: Action in accordance with either Shorts Service Bulletin: 1. SD360-27-10 Revision No. 1 for PT6A-65R engines; or 2. SD360-27-11 Revision No. 2 for PT6A-65AR Engines. Compliance: Prior to 30 November 1986. Background: Operational experience has found that excessive control column force is required during take-off under certain conditions.