{"id":"F2011L01723","name":"AD/DHC-1/44 Amdt 1 - Mandatory Modifications, Inspections and Replacements","slug":"ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":126215,"registerId":"commonwealth-F2011L01723-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"De Havilland DHC-1 (Chipmunk) Series Aer","sectionType":"division","heading":"De Havilland DHC-1 (Chipmunk) Series Aeroplanes","content":"### De Havilland DHC-1 (Chipmunk) Series Aeroplanes\n\n| AD/DHC-1/44 Amdt 1 | Mandatory Modifications, Inspectionsand Replacements | 17/2011 |\n| ------------------ | ---------------------------------------------------- | ------- |\n\n| Applicability: | All Canadian production DHC-1 aircraft as specified in the requirement document.                                                                                                                                                                                                                                                                                                                    |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Carry out the modifications, inspections and replacements in accordance with Transport Canada Airworthiness Directive CF-49-05.Note: De Havilland Aircraft of Canada Limited Technical News Sheet Leaflet C-3, C-4, C-6, C-7, C-10 and Design Leaflets CM1003, Mod.278, Mod.322 refer.                                                                                                              |\n| Compliance:    | Within 6 months after the effective date unless previously accomplished.                                                                                                                                                                                                                                                                                                                            |\n|                | This Amendment becomes effective on 26 August 2011.                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | Modifications, inspections and replacements relating to Rudder Bars, Wheel Hubbolts, Brake Disc Clips, Support Brackets, Rudder Mass Balance Weight, Fuselage Longerons, Helical Tension Spring, Safety Harness Attachments, and Rear Brake Lever assemblies are mandated by Transport Canada.Amendment 1 of this directive reduces the applicability of this directive to Canadian Chipmunks only. |\n\n![](image.001.png)  \nMike Higgins  \nDelegate of the Civil Aviation Safety Authority\n\n23 August 2011","sortOrder":0},{"sectionNumber":"AD/DHC-1/44 Amdt 1","sectionType":"part","heading":"AD/DHC-1/44 Amdt 1","content":"## AD/DHC-1/44 Amdt 1","sortOrder":1},{"sectionNumber":"Mandatory Modifications, Inspectionsand ","sectionType":"part","heading":"Mandatory Modifications, Inspectionsand Replacements","content":"## Mandatory Modifications, Inspections  \nand Replacements","sortOrder":2},{"sectionNumber":"17/2011","sectionType":"part","heading":"17/2011","content":"## 17/2011","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"This amendment explicitly narrows the scope from previous versions. The background states 'Amendment 1 of this directive reduces the applicability of this directive to Canadian Chipmunks only,' indicating the original AD/DHC-1/44 covered a broader range of aircraft (likely including British-built Chipmunks) before this restriction."},"complexity_factors":["Single, clearly defined applicability (Canadian production DHC-1 aircraft only)","Single requirement referencing an external Canadian directive (CF-49-05) rather than spelling out technical details","Simple compliance deadline (6 months from effective date)","No defined terms section — relies on external technical documents","No conditional logic or nested exceptions","Background section provides plain explanation of the amendment's purpose","Short document (approximately 200 words of substantive content)"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of Canadian-built De Havilland DHC‑1 Chipmunks to carry out required safety modifications, inspections and part replacements addressing control, braking and structural elements to prevent loss of control or structural failure. Compliance was required within six months of 26 August 2011 (unless already completed). This amendment narrows applicability to Canadian‑manufactured Chipmunks only, excluding British-built aircraft covered earlier."},"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":5,"scope_assessment":{"changed":true,"description":"Amendment 1 reduces the directive's applicability so it applies only to Canadian-production DHC‑1 (Chipmunk) aircraft. The requirement and compliance timing remain, but fewer aircraft are now covered."},"complexity_factors":["References to external mandatory documents (Transport Canada AD CF-49-05 plus multiple De Havilland Technical News Sheets and Design Leaflets) increase research and compliance complexity.","Multiple discrete technical components are affected (rudder bars, wheel hub bolts, brake disc clips, support brackets, mass balance weight, longerons, springs, harness attachments, brake lever assemblies), requiring varied trades and parts.","Compliance timeframe: 6 months from effective date creates scheduling and operational‑downtime pressure for owners/operators.","Enforcement and applicability are determined by CASA but rely on Transport Canada specifications, creating cross-jurisdictional implementation dependency.","Amendment changes scope (reduces applicability) requiring operators to confirm aircraft provenance and applicability status.","Potential cost and supply-chain burdens on private owners/operators who must fund and arrange the work."],"plain_english_summary":"This airworthiness directive requires owners/operators of Canadian-production De Havilland DHC‑1 (Chipmunk) aeroplanes to carry out mandatory modifications, inspections and replacements in accordance with Transport Canada Airworthiness Directive CF-49-05. (Applicability; Requirement)\n\nCompliance must be completed within six months of the effective date; the costs and execution are the responsibility of aircraft owners/operators and CASA enforces compliance. (Compliance; Background) Amendment 1 narrows the directive’s scope to Canadian-produced Chipmunks only."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements","history":"/api/acts/ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements/history","analysis":"/api/acts/ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements/analysis","conflicts":"/api/acts/ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements/conflicts","importantCases":"/api/acts/ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements/important-cases","documents":"/api/acts/ad-dhc-1-44-amdt-1-mandatory-modifications-inspections-and-replacements/documents"}}