COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series AD/TFE731/5 Compressor Tie Rod - Replacement 3/86 Applicability: All TFE731-2-1C, -2-2B, -3-1E, -3-1G, -3-1F, -3-1C, -3-1H, -2-2J, -3-1K models. Document: AiResearch Alert SB No. TFE731-A72-3140, or AD/AIR-T/37. Requirement: Part 1 - For engines listed by their S/Nos. in paragraph "D" of the requirement document: Change the compressor tie rod in accordance with the requirement document. Part 2 - For all applicable models whose engine S/Nos. is not listed in Paragraph "D" of requirement document: Replace any compressor tie rod of a S/No. listed under the heading of "Special Category" in Paragraph "D" of the requirement document. Compliance: Part 1 - Within 100 hours time in service after 30 September 1980. Part 2 - At the next hot end inspection or at the next time access to the area is gained for another purpose whichever occurs first. Background: This Directive is issued as the result of notification from the engine manufacturer that some tie rods made from suspect material were used during engine manufacture or overhaul.