{"id":"F2006B09137","name":"AD/DHC-6/49 Amdt 3 - Flight Control Rods","slug":"ad-dhc-6-49-amdt-3-flight-control-rods","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115694,"registerId":"commonwealth-F2006B09137-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/49 Amdt 3 - Flight Control Rods","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\n# AD/DHC-6/49\n\nAmdt 3\n\nApplicability: Model DHC-6 series.\n\n# Flight Control Rods 2/93\n\n \n\nRequirement: Action in accordance with the technical requirements of Transport Canada AD CF-80-03R3.\n\n \n\nNote: De Havilland SB 6/390 Revision A and SB 6/502 refer.\n\n \n\nCompliance: As specified in the Requirement Document with a revised effective date of 3 February 1992 for Australian registered aircraft.\n\n \n\nThe compliance of the previous issue of this Directive remains unchanged. This Amendment is effective from 4 February 1993.\n\n \n\nBackground: The flight control rods have been the subject of a series of special inspections, modifications, and replacements to prevent longitudinal stress corrosion cracking. Amendment 2 mandated the replacement of 2024-T3 alloy flight control rods and provided an increase in the inspection interval of 6061-T6 control rods pursuant to Canada’s Aging Aircraft program. Amendment 3 is issued in response to a revision of the relevant Country of Origin AD, which extends the deadline for removal of the 2024-T3 rods because of lack of replacements, subject to the alternative of inspecting the rods during this extension.\n\n \n","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 3 does not change which aircraft are covered (Model DHC‑6) but alters compliance measures: it extends the deadline for removal of 2024‑T3 control rods due to lack of replacements and authorises inspections as an alternative during that extension, while retaining the prior change to 6061‑T6 inspection intervals (Background; Compliance)."},"complexity_factors":["Cross-reference to Transport Canada AD CF-80-03R3 as the operative technical requirement (Requirement).","Material-specific measures: different treatment for 2024‑T3 alloy rods (replacement or inspection) versus 6061‑T6 rods (increased inspection interval) (Background, Amendment 2/3).","Amendment history and revised effective/compliance dates for Australian-registered aircraft (Compliance; Amendment effective 4 February 1993; revised effective date 3 February 1992).","Alternative compliance path permitted during extension (inspect rods during extension instead of immediate removal) (Background).","References to manufacturer service bulletins (De Havilland SB 6/390 Rev A and SB 6/502) rather than full technical detail (Note).","Operational burden sits on aircraft owners/operators to carry out inspections, replacements and compliance record-keeping."],"plain_english_summary":"This airworthiness directive requires operators of DHC‑6 (Twin Otter) aircraft to follow Transport Canada AD CF‑80‑03R3 for inspection or replacement of flight control rods: owners must replace affected 2024‑T3 alloy rods or, under the amendment, may continue to operate subject to repeated inspections while replacements remain unavailable; inspection intervals for 6061‑T6 rods remain extended. The Civil Aviation Safety Authority sets the compliance dates; operators pay for inspections or replacements and must record compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: ensuring airworthiness of DHC-6 flight control rods. Amendment 3 simply updates the compliance timeline and inspection requirements in response to parts availability issues, without expanding to other aircraft systems or components."},"complexity_factors":["Short, single-purpose document (1 page)","Only 2 defined technical terms (2024-T3 and 6061-T6 aluminium alloys)","Single cross-reference to external Canadian regulation (Transport Canada AD CF-80-03R3)","Simple conditional logic: replace OR inspect during extension period","No nested exceptions or recursive definitions","Clear compliance dates and applicability statement"],"plain_english_summary":"This CASA Airworthiness Directive mandates following Transport Canada AD CF-80-03R3 for DHC‑6 Twin Otter flight control rods to address stress corrosion cracking. Operators must remove susceptible 2024‑T3 alloy rods, inspect 6061‑T6 rods at required intervals, and may use a limited deadline extension for replacements only if inspections are more frequent. It affects Australian‑registered Twin Otter owners and maintenance organisations and aims to prevent control‑rod failure and possible loss of control while accommodating parts availability."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-49-amdt-3-flight-control-rods","history":"/api/acts/ad-dhc-6-49-amdt-3-flight-control-rods/history","analysis":"/api/acts/ad-dhc-6-49-amdt-3-flight-control-rods/analysis","conflicts":"/api/acts/ad-dhc-6-49-amdt-3-flight-control-rods/conflicts","importantCases":"/api/acts/ad-dhc-6-49-amdt-3-flight-control-rods/important-cases","documents":"/api/acts/ad-dhc-6-49-amdt-3-flight-control-rods/documents"}}