{"id":"F2006B09006","name":"AD/DHC-1/25 Amdt 1 - Wing Flap Inner Hinge Bracket and Reinforcing Channel","slug":"ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52660,"registerId":"commonwealth-F2006B09006-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-1/25 Amdt 1 - Wing Flap Inner Hinge Bracket and Reinforcing Channel","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)  \nDe Havilland DHC-1 (Chipmunk) Series Aeroplanes\n\nAD/DHC-1/25\n\nAmdt 1\n\n  \n\nWing Flap Inner Hinge Bracket and Reinforcing Channel\n\n  \n11/85\n\nApplicability: All English production aircraft.\n\nDocument: British Aerospace TNS CT(C1) No. 166, Issue 2.\n\nCompliance: 1. Inner Hinge Bracket: Within 100 hours time in service after 30 November 1973 and thereafter at each major inspection or at intervals not exceeding 600 hours time in service whichever occurs first.\n\n2. Reinforcing Channel:\n\nPrior to the issue of the next Maintenance Release after 30 November 1985, and thereafter at each major inspection or at intervals not exceeding 300 hours time in service, whichever occurs first.\n\nNote: Accomplishment of modification in accordance with Drawing No. RD.C1.WF.104 constitutes terminating action for the inspections in paragraph 3.2 of the TNS.\n\nBackground: Cracking has been reported in both of the subject flap components. It has been attributed to fatigue induced by repeated use of the footstep on the flap. The Inner Hinge Bracket inspections are unchanged from the previous issue of this Directive. However, the inspection of the Reinforcing Channel is a new requirement.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2322},"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 1 introduces a new inspection requirement for the Reinforcing Channel alongside the existing Inner Hinge Bracket inspection, but this is an incremental extension addressing the same root cause (fatigue cracking from footstep use) within the same aircraft system. It does not expand beyond the original purpose of ensuring wing flap structural integrity."},"complexity_factors":["External document incorporation by reference (British Aerospace TNS CT(C1) No. 166) without reproducing the actual inspection steps","Dual compliance triggers using 'whichever occurs first' conditional logic for recurring obligations","Different inspection intervals for two related components (600 hours vs 300 hours)","Technical aviation terminology requiring domain knowledge (Time in Service, Maintenance Release, terminating action)"],"plain_english_summary":"This directive requires regular inspections of the Inner Hinge Bracket and Reinforcing Channel on wing flaps of English-built De Havilland DHC-1 Chipmunks to detect fatigue cracks caused by using the flap as a footstep. It applies to all owners/operators and mandates repeat checks at specified maintenance intervals, with inspections to follow the referenced British Aerospace technical procedure. A specified structural modification, if done, removes the recurring inspection requirement."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel","history":"/api/acts/ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel/history","analysis":"/api/acts/ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel/analysis","conflicts":"/api/acts/ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel/conflicts","importantCases":"/api/acts/ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel/important-cases","documents":"/api/acts/ad-dhc-1-25-amdt-1-wing-flap-inner-hinge-bracket-and-reinforcing-channel/documents"}}