{"id":"F2006B08639","name":"AD/CON/61 - Crankshaft Removal/Inspection","slug":"ad-con-61-crankshaft-removal-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51665,"registerId":"commonwealth-F2006B08639-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CON/61 - Crankshaft Removal/Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nTeledyne Continental Motors Piston Engines\n\nAD/CON/61 Crankshaft Removal/Inspection 10/92 DM\n\nApplicability: All Teledyne Continental piston engines that have been overhauled by or had the crankshaft disassembled for major work by Arnhem Aircraft Engineering Pty Ltd under Certificate of Approval No 4049 during the period 1 January 1990 to 6 August 1992.\n\nRequirement: 1. Remove the crankshaft assembly and dimensionally check the diameters of all bearing journals.\n\n    2. Crankshafts with any bearing journal diameter less than the STANDARD dimension listed in the relevant Teledyne Continental Engine Overhaul Manual are to be quarantined and the local CAA Airworthiness District Office notified.\n\n    3. Crankshafts with diameters for all bearing journals at the STANDARD dimension listed in the relevant Teledyne Continental Engine Overhaul Manual may be refitted to an engine.\n\nCompliance: For installed engines \\- Prior to the 31 August 1992.\n\nFor uninstalled engines \\- Before installation into an aircraft.\n\nBackground: Four crankshaft assemblies repaired by the grinding of bearing journals on behalf of Arnhem Aircraft Engineering Pty Ltd have been found with grinding cracks, two of which failed in flight. Arnhem Aircraft Engineering Pty Ltd has been unable to satisfy the CAA (Aust) as to the location or number of crankshafts repaired by grinding on its behalf.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific manufacturing defect in crankshafts processed by a single repair shop during a defined 2.5-year period. The directive has not expanded beyond this original safety purpose."},"complexity_factors":["Single, discrete safety issue addressed with straightforward mechanical inspection requirements","Only 3 defined applicability criteria (engine type, specific repair shop, specific date range)","Clear binary compliance pathway (measure → either quarantine or refit)","No nested exceptions, cross-references to other legislation, or conditional sub-clauses","Single deadline with simple alternative for uninstalled engines","Total length: approximately 250 words"],"plain_english_summary":"CASA directs owners/operators of Teledyne Continental piston engines overhauled or with major crankshaft work by Arnhem Aircraft Engineering Pty Ltd between 1 Jan 1990 and 6 Aug 1992 to remove and inspect crankshaft bearing journals. If any journal measures undersize, quarantine the crankshaft and notify CASA; if within limits, refit.\n\nThe AD follows two in‑flight crankshaft failures from improper grinding; it aims to catch potentially affected crankshafts before further service. Deadlines: installed engines by 31 Aug 1992; uninstalled before installation."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive targets engines worked on by Arnhem Aircraft Engineering within the stated dates and prescribes inspection, quarantine and reporting. The instrument does not indicate a change of scope from its stated purpose in the text provided; it limits action to the named provider/date window and to crankshafts not meeting the STANDARD dimension."},"complexity_factors":["Limited, specific applicability by provider (Arnhem) and date range — requires identifying affected engines/records","Technical requirement to remove and dimensionally measure all bearing journals (precision measurement and access/downtime)","Reliance on an external reference STANDARD dimension in the Teledyne Continental Engine Overhaul Manual","Administrative steps: quarantine of substandard crankshafts and mandatory notification to local CAA Airworthiness District Office","Fixed compliance deadlines for installed and uninstalled engines","Potential follow-on costs: replacement, rework, parts sourcing and labour"],"plain_english_summary":"This Airworthiness Directive requires removal and dimensional inspection of crankshaft bearing journals on Teledyne Continental piston engines overhauled or whose crankshafts were disassembled by Arnhem Aircraft Engineering (Cert No 4049) between 1 Jan 1990 and 6 Aug 1992; journals below the STANDARD dimension must be quarantined and reported to the local CAA, and journals at STANDARD may be refitted. The rule imposes inspection, removal and possible replacement costs on aircraft owners/operators and maintenance organisations and mandates CAA notification because grinding cracks were found and Arnhem could not identify which crankshafts were ground."}},"importantCases":[],"_links":{"self":"/api/acts/ad-con-61-crankshaft-removal-inspection","history":"/api/acts/ad-con-61-crankshaft-removal-inspection/history","analysis":"/api/acts/ad-con-61-crankshaft-removal-inspection/analysis","conflicts":"/api/acts/ad-con-61-crankshaft-removal-inspection/conflicts","importantCases":"/api/acts/ad-con-61-crankshaft-removal-inspection/important-cases","documents":"/api/acts/ad-con-61-crankshaft-removal-inspection/documents"}}