{"id":"F2006B06508","name":"AD/RAD/51 - Rockwell International/Collins Aviation Division TDR-94D Transponder","slug":"ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48085,"registerId":"commonwealth-F2006B06508-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/RAD/51 - Rockwell International/Collins Aviation Division TDR-94D Transponder","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nRadio Communication and Navigation Equipment\n\nAD/RAD/51 Rockwell International/Collins Aviation\n\nDivision TDR-94D Transponder\n\n  \n6/93\n\nApplicability: Rockwell International/Collins Aviation Division TDR-94D Mode S Transponders installed on, but not limited to, the following airplanes:\n\nSaab 340A and 340B, Short Brothers SD3-60,\n\nde Havilland DHC-8 series, Grumman Gulfstram G1159 series,\n\nDassault Mystere-Falcon 200 and 900, Canadair Challenger CL-601 series, British Aerospace HS 125-700 series, and Beechcraft 300 series.\n\nRequirement: 1. Fabricate a placard with the following words in letters at least 25mm in height and install the placard within the pilot’s clear view on the instrument panel:\n\n\\`OPERATION OF TCAS II IN ANY MODE OTHER THAN THE “TA ONLY” MODE IS PROHIBITED’\n\n2. Modify the software of the transponder in accordance with the Accomplishment Instructions of Collins Service Bulletin TDR-94/94D-34-6 Revision 2 dated\n\n21 September 1992. (The placard mandated by Requirement 1 is no longer necessary after this Modification is incorporated.)\n\nNote: FAA AD 93-04-02 Amendment 39-8504 refers.\n\nCompliance: Requirement 1 \\- Prior to 7 June 1993.\n\nRequirement 2 \\- Prior to 1 December 1993.\n\nBackground: Tests have revealed that these Mode S Transponders, when operating in the resolution advisory mode, may loose the capability of co-ordinating with other aircraft. This could result in a near-hit situation or mid-air collision. Compliance with this Directive is intended to prevent collisions or near hits caused by failure of these Mode S Transponders.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2038},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope as an emergency safety intervention for a specific avionics defect. No expansion beyond the original technical remediation purpose."},"complexity_factors":["Very short, single-issue directive with only two compliance requirements","Limited applicability to one specific transponder model and enumerated aircraft types","Clear, absolute compliance dates with no conditional extensions or exceptions","No nested legislative cross-references—only refers to enabling regulations (Civil Aviation Regulations 1998 Part 39) and manufacturer service bulletin","Plain language background section explaining the safety rationale without legal jargon"],"plain_english_summary":"This AD orders owners of certain Saab 340, DHC‑8 Dash 8, Gulfstream G1159, Dassault Falcon 200/900, Canadair Challenger CL‑601, BAe HS 125‑700 and Beechcraft 300 series aircraft with Rockwell Collins TDR‑94D Mode S transponders to fix a software fault that can cause TCAS resolution‑advisory coordination failures and risk mid‑air collisions. \n\nIt mandates an interim placard limiting TCAS to “TA only” pending installation of the manufacturer’s software update, after which the placard may be removed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder","history":"/api/acts/ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder/history","analysis":"/api/acts/ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder/analysis","conflicts":"/api/acts/ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder/conflicts","importantCases":"/api/acts/ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder/important-cases","documents":"/api/acts/ad-rad-51-rockwell-international-collins-aviation-division-tdr-94d-transponder/documents"}}