{"id":"F2006B06429","name":"AD/R22/23 - Main Rotor Gearbox Ring Gear Bolts - Inspection and Modification","slug":"ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47815,"registerId":"commonwealth-F2006B06429-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/R22/23 - Main Rotor Gearbox Ring Gear Bolts - Inspection and Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Robinson R22 Series Helicopters\n\n \n\n# AD/R22/23  Main Rotor Gearbox Ring Gear Bolts - Inspection and Modification\n\nApplicability: All R22 servo helicopters.\n\n# 10/84\n\n \n\nRequirement: Robinson service bulletin No. 43 dated 24 August 1984, or FAA AD 84-18-04 of 6 September 1984.\n\n \n\nCompliance: 1. Inspect in accordance with the Requirement Document.\n\n \n\nWithin the next 15 hours time in service after 13 September 1984. Thereafter at intervals not exceeding 50 hours time in service from the last inspection.\n\n \n\n2. Modify the main rotor gearbox in accordance with Robinson Kit No. KI-37 within the next 200 hours time in service after 13 September 1984.\n\n \n\nNote: When gearbox has been modified, inspection may be discontinued.\n\n \n\nBackground:  There have been cases of ring gear bolt breaking/head separation in main rotor gearbox during normal service.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a vintage 1984 Airworthiness Directive that remains tightly focused on its original purpose: addressing a specific mechanical defect in Robinson R22 helicopter main rotor gearboxes. The scope has not expanded beyond the original safety-critical bolt failure issue."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements (inspection and modification)","No defined terms section — uses plain language and references external documents","Simple conditional logic: 'When gearbox has been modified, inspection may be discontinued'","Single cross-reference to external technical documents (Robinson service bulletin and FAA AD)","Clear applicability statement with no exceptions or nested conditions"],"plain_english_summary":"This CASA Airworthiness Directive applies to Robinson R22 helicopters. It requires frequent inspections of the main rotor gearbox ring-gear bolts (first within 15 flight hours, then every 50 hours) and mandates installing Robinson Kit KI‑37 within 200 flight hours from 13 September 1984.\n\nIt matters because bolt failures on the ring gear can lead to catastrophic rotor loss; the kit provides a permanent fix and ends the repetitive inspections."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains as originally targeted: all R22 servo helicopters must undergo specified inspections and then a gearbox modification to address ring‑gear bolt failures. The directive does not expand or narrow the affected fleet or the core mechanical mandate beyond those measures."},"complexity_factors":["Applicability limited to a single model group: all Robinson R22 servo helicopters (straightforward target population).","Two-step compliance: immediate recurring inspections plus a later mandatory modification (adds scheduling and logistics).","Time-based deadlines: short initial deadline (15 hours), recurring interval (50 hours), and modification deadline (200 hours) introduce operational constraints.","Dependence on external documents: requires following Robinson Service Bulletin No.43 or FAA AD 84‑18‑04 (must obtain and interpret those documents).","Modification effect: fitting Kit KI-37 allows discontinuation of inspections (creates a compliance end-state to track).","Practical burdens: parts availability, labour, certified maintenance release, and record-keeping for operators and maintainers.","Regulatory enforcement: mandatory under CASA airworthiness directive regime (noncompliance risk).","Safety-critical equipment: failure consequence high, which raises urgency but does not complicate legal text."],"plain_english_summary":"This airworthiness directive requires owners/operators of Robinson R22 “servo” helicopters to inspect the main rotor gearbox ring‑gear bolts promptly and to fit a modification kit (Robinson KI‑37) within a set time. The directive responds to reported bolt breakages and is intended to prevent in‑service failures. Operators pay for inspections and the kit; inspections must be repeated on a schedule until the kit is installed, after which inspections may be stopped. Compliance follows Robinson Service Bulletin No.43 or FAA AD 84‑18‑04."}},"importantCases":[],"_links":{"self":"/api/acts/ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification","history":"/api/acts/ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification/history","analysis":"/api/acts/ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification/analysis","conflicts":"/api/acts/ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification/important-cases","documents":"/api/acts/ad-r22-23-main-rotor-gearbox-ring-gear-bolts-inspection-and-modification/documents"}}