{"id":"F2006B04689","name":"AD/BELL 47/58 Amdt 1 - Drag Brace Clevis","slug":"ad-bell-47-58-amdt-1-drag-brace-clevis","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44441,"registerId":"commonwealth-F2006B04689-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 47/58 Amdt 1 - Drag Brace Clevis","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)  \nBell Helicopter Textron 47 (All Variants) Series Helicopters\n\nAD/BELL 47/58\n\nAmdt 1\n\n  \nDrag Brace Clevis 11/67\n\nApplicability: All model 47 series with wooden main rotor blades.\n\nRequirement: 1. Remove drag brace clevises P/N 47-110-235-1 and inspect for cracking in the root of the first six threads from the fork end of the clevis before re-installation. The inspection is to be performed using a fluorescent magnetic particle technique such as Magnaglow or equivalent with residual longitudinal magnetisation.\n\n    2. Alternatively, replace existing clevises with \\-\n\n    (a) new parts,\n\n    (b) serviceable used parts that have either not been involved with main rotor damage or, if so, have been inspected in accordance with para. 1 above.\n\nCompliance: 1. Before further flight following damage to the main rotor blades sustained through contact with foreign objects whilst rotating.\n\n2. For parts inspected in accordance with paragraph 1 above, repeat the inspection at between 40 and 50 hours time in service following re-installation.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive focused on a specific known defect in a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific mechanical part targeted (P/N 47-110-235-1)","Only two compliance pathways (inspect or replace)","Clear, time-bound compliance triggers (post-damage, plus 40-50 hour follow-up)","One technical method specified (fluorescent magnetic particle inspection) with acceptable alternative named","Limited applicability (Bell 47 series with wooden main rotor blades only)","No nested definitions, cross-references to other legislation, or conditional exceptions"],"plain_english_summary":"CASA requires owners/operators of Bell 47 helicopters with wooden main rotor blades to inspect or replace the drag brace clevis (P/N 47‑110‑235‑1) because cracks near its threaded end can lead to catastrophic rotor failure. \n\nAction is mandatory immediately after any rotor strike/damage and, if inspected rather than replaced, re‑inspection is required after 40–50 flight hours. This affects all Australian operators, maintenance organisations, and owners of affected Bell 47s."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied text is labelled as Amendment 1 but does not describe the prior wording or what was altered. From the document alone, no information is provided to determine a change in scope from an earlier version."},"complexity_factors":["Specific part-level applicability (P/N 47-110-235-1) narrows scope to particular hardware (Requirement ¶1).","Mandated non‑destructive test method: fluorescent magnetic-particle inspection with residual longitudinal magnetisation — requires specialised equipment and trained personnel (Requirement ¶1).","Conditional compliance timing: action required following main-rotor damage from foreign objects, not on a fixed calendar (Compliance ¶1).","Follow-up inspection window (40–50 hours TIS) after reinstallation adds a recurring short-term monitoring obligation (Compliance ¶2).","Permits reuse of serviceable used parts only if they meet damage/inspection conditions, creating traceability and recordkeeping needs (Requirement ¶2(b)).","Removal before inspection increases downtime and labour compared with in‑place checks (Requirement ¶1)."],"plain_english_summary":"Mandates that Bell 47 helicopters with wooden main rotor blades have drag-brace clevises P/N 47-110-235-1 removed and either inspected for cracking using a fluorescent magnetic-particle technique with residual longitudinal magnetisation or replaced with new/serviceable parts. It applies after main-rotor damage from foreign-object contact and, where parts are inspected and reinstalled, requires a repeat inspection after 40–50 hours. Aircraft operators bear the cost and must arrange the specialised non-destructive test or replacement."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-47-58-amdt-1-drag-brace-clevis","history":"/api/acts/ad-bell-47-58-amdt-1-drag-brace-clevis/history","analysis":"/api/acts/ad-bell-47-58-amdt-1-drag-brace-clevis/analysis","conflicts":"/api/acts/ad-bell-47-58-amdt-1-drag-brace-clevis/conflicts","importantCases":"/api/acts/ad-bell-47-58-amdt-1-drag-brace-clevis/important-cases","documents":"/api/acts/ad-bell-47-58-amdt-1-drag-brace-clevis/documents"}}