{"id":"F2011L01086","name":"AD/DHC-1/36 Amdt 2 - Flap Operating Cables","slug":"ad-dhc-1-36-amdt-2-flap-operating-cables","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":86883,"registerId":"commonwealth-F2011L01086-current","compilationNumber":null,"startDate":"2026-04-02","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-1/36 Amdt 2 | Flap Operating Cables | 12/2011 |\n| ------------------ | --------------------- | ------- |\n\n| Applicability: | English production (C1) all models and Portuguese (T Mk 20) production models. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement: | Action in accordance with British Aerospace TNS CT(C1) No.184 Issue 4.Note: UK CAA AD 001-03-95 refers. |\n| Compliance: | At intervals not to exceed 150 flight hours or at the annual inspection, whichever occurs first. |\n| | This Amendment becomes effective on 21 June 2011. |\n| Background: | Cases have been reported of failure of the Flap operating cable which in one case led to a flap asymmetry situation during the final phase of landing. Investigation has shown the failures were due to either incorrect rigging of the control cables or inadequate maintenance of the control pulleys.Amendment 1 was issued in response to a revision of the Requirement document, which introduced a repetitive inspection of the latch plate and flap lever quadrant for wear.This inspection was originally introduced in 1995, and up until now, Australia has had no Portuguese manufactured Chipmunks on the register, hence the CASA AD has only been effective for English production Chipmunks.This amendment is to include the Portuguese manufactured Chipmunk in the applicability for this AD, as a recent review of documents, shows that this inspection is also applicable to the Portuguese model (T Mk 20).There are no technical changes to the requirements or compliance of this AD. |\n\n![](image.001.png) \nGlen Steemson \nDelegate of the Civil Aviation Safety Authority\n\n16 June 2011","sortOrder":0},{"sectionNumber":"AD/DHC-1/36 Amdt 2","sectionType":"part","heading":"AD/DHC-1/36 Amdt 2","content":"## AD/DHC-1/36 Amdt 2","sortOrder":1},{"sectionNumber":"Flap Operating Cables","sectionType":"part","heading":"Flap Operating Cables","content":"## Flap Operating Cables","sortOrder":2},{"sectionNumber":"12/2011","sectionType":"part","heading":"12/2011","content":"## 12/2011","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 2 expands the AD's applicability to include Portuguese‑manufactured Chipmunks (T Mk 20), whereas earlier CASA AD coverage had applied only to English production (C1). The substantive inspection requirements, compliance intervals and technical content remain unchanged. The amendment became effective 21 June 2011 ('Applicability'; 'Compliance'; 'Background')."},"complexity_factors":["External normative reference: requires following British Aerospace TNS CT(C1) No.184 Issue 4 rather than setting full procedures in the AD ('Requirement').","Cross‑jurisdictional reference: notes UK CAA AD 001‑03‑95 as related material ('Requirement').","Applicability distinctions by production origin (English C1 and now Portuguese T Mk 20) require operators to verify aircraft provenance ('Applicability').","Repetitive compliance interval (every 150 flight hours or at annual inspection) creates ongoing operational and maintenance scheduling burden ('Compliance').","Investigation‑based mandate: inspections target specific failure modes (incorrect rigging or pulley maintenance) identified in the AD ('Background').","Amendment alters scope without technical changes, which may require administrative tracking of fleet eligibility but not new technical procedures ('Background')."],"plain_english_summary":"This airworthiness directive requires operators of De Havilland DHC‑1 (Chipmunk) English‑production (C1) and Portuguese‑production (T Mk 20) aeroplanes to carry out repetitive inspections of flap operating cables, latch plates, quadrants and pulleys in accordance with British Aerospace TNS CT(C1) No.184 Issue 4, at intervals not exceeding 150 flight hours or at the annual inspection (see 'Requirement' and 'Compliance'). Operators and maintenance organisations pay for inspections and repairs; CASA enforces compliance. Amendment 2 only extends applicability to Portuguese‑built Chipmunks and does not change technical requirements ('Background')."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment does not expand the scope beyond the original safety purpose. It merely corrects an administrative gap by adding Portuguese-manufactured aircraft to the applicability, which should have been included from the outset based on the technical requirements. The core safety mandate (flap cable inspections) remains unchanged from the original 1995 directive."},"complexity_factors":["Very short document (approximately 250 words of substantive content)","Only 2 defined applicability categories (English C1 models, Portuguese T Mk 20)","Single compliance requirement with clear time interval (150 flight hours or annual)","No nested exceptions or conditional logic — straightforward 'inspect or else' mandate","Cross-reference to only one external technical document (British Aerospace TNS CT(C1) No.184 Issue 4)","Background section provides clear rationale without legal obfuscation"],"plain_english_summary":"This AD mandates inspections of flap operating cables on De Havilland DHC‑1 Chipmunk aeroplanes every 150 flight hours or annually to prevent dangerous flap asymmetry from cable failure. Amendment 2 expands the applicability to include Portuguese‑built T Mk 20s (previously only English‑built C1), so all affected Chipmunks registered in Australia must comply."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-1-36-amdt-2-flap-operating-cables","history":"/api/acts/ad-dhc-1-36-amdt-2-flap-operating-cables/history","analysis":"/api/acts/ad-dhc-1-36-amdt-2-flap-operating-cables/analysis","conflicts":"/api/acts/ad-dhc-1-36-amdt-2-flap-operating-cables/conflicts","importantCases":"/api/acts/ad-dhc-1-36-amdt-2-flap-operating-cables/important-cases","documents":"/api/acts/ad-dhc-1-36-amdt-2-flap-operating-cables/documents"}}