{"id":"F2006B09106","name":"AD/DHC-6/19 - Propeller and Power Control Lever Interlock - Mod","slug":"ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115659,"registerId":"commonwealth-F2006B09106-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/19 - Propeller and Power Control Lever Interlock - Mod","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  DHC-6 (Twin Otter) Series Aeroplanes\n\n \n\nAD/DHC-6/19 Propeller and Power Control Lever Interlock - Mod\n\n\n10/69\n\n \n\nApplicability: All models with S/Nos. 2 to 213 excluding 30, 58, 96, 148, 206, 208, 210 and 212. Document:               De Havilland of Canada SB No. 6/183, Rev. B.\n\nCompliance: Within 100 hours time in service after 23 December 1969.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2341},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standalone, original airworthiness directive targeting a specific safety-critical mechanical modification for defined aircraft serial numbers. The scope remains focused on the propeller/power lever interlock modification without expansion to unrelated systems."},"complexity_factors":["Single, specific mechanical modification requirement with clear technical reference","Limited applicability scope with explicit serial number exclusions (8 exceptions)","Simple compliance metric: 100 hours time in service from specified date","No nested conditions, exceptions, or cross-references to other legislative instruments"],"plain_english_summary":"This mandatory Airworthiness Directive requires owners/operators of De Havilland DHC‑6 Twin Otters (serials 2–213, excluding 30, 58, 96, 148, 206, 208, 210, 212) to modify the propeller/power-lever interlock to prevent inadvertent feathering.  \n\nWork must follow De Havilland Service Bulletin No. 6/183 Revision B and be completed within 100 flight hours after 23 December 1969 to eliminate the risk of sudden loss of thrust and potential loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod","history":"/api/acts/ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod/history","analysis":"/api/acts/ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod/analysis","conflicts":"/api/acts/ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod/conflicts","importantCases":"/api/acts/ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod/important-cases","documents":"/api/acts/ad-dhc-6-19-propeller-and-power-control-lever-interlock-mod/documents"}}