COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes AD/HS 748/5 Engine Subframe Tubular Struts 13/94 Applicability: All engine sub frames which have been installed on aircraft longer than 6 years, and engine sub frames whose previous radiographic examination took place more than 7 years ago. Requirement: Action in accordance with Jetstream Aircraft Mandatory Service Bulletin HS748-54/25. Note: UK CAA AD 0119 refers. Compliance: For engine sub frames which have exceeded 6 years but not 10 years from new, or from the date of the last scheduled inspection, or from the date of sub frame replacement, the next radiographic inspection must be done within the following periods from 8 December 1994: 1. In excess of 6 years but not exceeding 8 years - examine prior to 8 December 1995. b. In excess of 8 years but not exceeding 9 years - examine prior to 8 September 1995. c. In excess of 9 years but not exceeding 10 years - examine prior to 8 June 1995. Background: Internal corrosion in the tubes of several sub frame struts has been revealed following the current scheduled radiographic examination of the engine sub frame.