{"id":"F2006B09124","name":"AD/DHC-6/36 Amdt 2 - Overhead Console Control Quadrants","slug":"ad-dhc-6-36-amdt-2-overhead-console-control-quadrants","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115677,"registerId":"commonwealth-F2006B09124-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/36 Amdt 2 - Overhead Console Control Quadrants","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nDHC-6 (Twin Otter) Series Aeroplanes\n\nAD/DHC-6/36\n\nAmdt 2\n\n  \nOverhead Console Control Quadrants 3/95\n\nApplicability: Model DHC-6 series aircraft.\n\nRequirement: Accomplish the following as required by Transport Canada AD CF-73-06R2:\n\n    Inspect the control quadrant assembly in accordance with Part A of Accomplishment Instructions of de Havilland Service Bulletin 6/519.\n\nIf no cracks are found per the criteria of Part A of the Accomplishment Instructions of Service Bulletin 6/519, carry out periodic inspections in accordance with de Havilland Inspection Requirements Manual PSM 1-6-7, Chapter 76 until Modification 6/1895 is incorporated.\n\nIf cracks are found per the criteria of Part A, paragraph 4 of Service Bulletin 6/519, incorporate de Havilland Modification 6/1895 (SB 6/519 refers).\n\nIf cracks are found per the criteria of Part A, paragraph 5 of Service Bulletin 6/519, incorporate Modification 6/1895 within 200 flight hours.\n\nInspect for crack propagation at 100 flight hours since last inspection to confirm that the magnitude and location of cracks remain within given limits.\n\n    2. Incorporate Modification 6/1895.\n\nNote: Incorporation of de Havilland Modification 6/1895 provides terminating action for this Directive.\n\nCompliance: 1. Within 100 hours time in service after 2 March 1995.\n\n2. Prior to 1 January 1997.\n\nBackground: Cracking and fracture of the control cable quadrants (P/N C6CE 1010-27 and \\-29) in the overhead control console were found on aircraft in service. Amendment 1 required modification action in lieu of on-going repetitive inspections.\n\nAmendment 2 is issued as a result of reports of in-service cracking of the previously modified quadrants, and further inspections are required until an improved modification is incorporated.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original AD (and Amendment 1) intended to solve the cracking problem through Modification 6/1895 as a terminating action. However, Amendment 2 reveals this modification proved insufficient — cracks reappeared in modified aircraft. The scope expanded from a simple 'inspect and fix' directive to an ongoing surveillance regime requiring repeated inspections until an 'improved modification' could be developed and installed. The regulatory burden increased significantly: operators who thought they were done after the modification now had to resume periodic inspections."},"complexity_factors":["Multiple conditional pathways (if no cracks / if cracks found under different criteria / if cracks found under paragraph 4 vs paragraph 5)","Cross-references to external documents: Transport Canada AD CF-73-06R2, de Havilland Service Bulletin 6/519, and de Havilland Inspection Requirements Manual PSM 1-6-7","Nested compliance deadlines (initial 100 hours, then 200 hours for certain crack findings, then hard deadline of 1 January 1997)","Technical aviation terminology requiring specialized knowledge (control quadrants, part numbers, flight hours, time in service)","Amendment history creates layered requirements (original AD, Amendment 1, Amendment 2 with revised understanding of the fix)"],"plain_english_summary":"Australia's CASA Airworthiness Directive requires operators of de Havilland DHC‑6 Twin Otter aircraft to inspect overhead control quadrants for cracking and to install a permanent repair (Modification 6/1895) by set deadlines. Cracked quadrants have caused in‑flight failures and potential loss of control, so the AD mandates recurring inspections until the approved fix is fitted, with a final compliance deadline and Amendment 2 adding inspections after earlier repairs proved inadequate."},"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":4,"scope_assessment":{"changed":true,"description":"Scope was broadened by this amendment: Amendment 1 previously replaced repetitive inspections with a modification, but Amendment 2 reintroduces inspections (including interim re‑inspections and deadlines) because reports showed cracking of previously modified parts. The directive therefore requires further inspections until the improved Modification 6/1895 is incorporated, with specified compliance flight‑hour and calendar deadlines (Background; Requirement; Compliance)."},"complexity_factors":["Branching compliance outcome: different actions depend on inspection findings (no cracks → periodic inspections; cracking at two severity thresholds → immediate or 200 flight‑hour modification) (Requirement: Service Bulletin 6/519, Parts A and paragraphs 4–5).","Multiple referenced documents: requires following Transport Canada AD CF‑73‑06R2, de Havilland Service Bulletin 6/519, and Inspection Requirements Manual PSM 1‑6‑7 (Requirement section).","Short interim intervals: 100 flight‑hour re‑inspection to monitor crack propagation after detection and a global 100 hours time‑in‑service compliance window (Inspect for crack propagation; Compliance: within 100 hours).","Terminating action linkage: incorporation of Modification 6/1895 ends repetitive inspections, creating a one‑time upgrade path (Note: terminating action).","Clear deadlines tied to calendar date and flight hours: modification must be incorporated prior to a specified date (1 Jan 1997) if not earlier (Compliance: prior to 1 January 1997).","Applicability scope limited to a single aircraft family (Model DHC‑6 series) but affects all operators of those models (Applicability).","Operational and cost impact concentrated on operators/owners who must fund inspections and modification work and schedule aircraft downtime (Requirement; Compliance).","Traceability and enforcement complexity: regulator relies on service bulletin conformity and operator recordkeeping to verify compliance."],"plain_english_summary":"This airworthiness directive requires DHC-6 (Twin Otter) operators to inspect the overhead control-quadrant assembly per de Havilland Service Bulletin 6/519 and, where specified crack criteria are met, to install Modification 6/1895. It sets short inspection intervals (including a 100‑flight‑hour check) and firm compliance deadlines, and states that the modification is terminating action. Operators bear the cost and must change maintenance and inspection practices to meet the specified intervals and modification timeline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-36-amdt-2-overhead-console-control-quadrants","history":"/api/acts/ad-dhc-6-36-amdt-2-overhead-console-control-quadrants/history","analysis":"/api/acts/ad-dhc-6-36-amdt-2-overhead-console-control-quadrants/analysis","conflicts":"/api/acts/ad-dhc-6-36-amdt-2-overhead-console-control-quadrants/conflicts","importantCases":"/api/acts/ad-dhc-6-36-amdt-2-overhead-console-control-quadrants/important-cases","documents":"/api/acts/ad-dhc-6-36-amdt-2-overhead-console-control-quadrants/documents"}}