{"id":"F2006B10710","name":"AD/HU 369/48 - Main Rotor Lead-Lag Bolts - Inspection for Corrosion","slug":"ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116683,"registerId":"commonwealth-F2006B10710-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/48 - Main Rotor Lead-Lag Bolts - Inspection for Corrosion","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)  McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\n \n\n# AD/HU 369/48 Main Rotor Lead-Lag Bolts - Inspection\n\nfor Corrosion\n\nApplicability: All model 369D and 369H series helicopters.\n\n# 7/81\n\n \n\nRequirement: In accordance with the procedures laid down in Section 7 of the applicable Basic H.M.I., inspect the inner bores of the lead-lag bolts for the presence of corrosion.\n\n \n\nIf corrosion is found, treat the bolts in accordance with the manufacturers instructions.\n\n \n\nCompliance: Within 100 hours time in service after 31 July 1981, and thereafter at intervals not exceeding 300 hours time in service.\n\n \n\nBackground: There has been one local occurrence of failure of a lead- lag bolt on a model 369H helicopter. The failure is believed to be due to hydrogen embrittlement induced from a corrosion reaction inside the lower bore of the bolt. There is no inspection of the lead-lag bolts listed in the H.M.I. inspection schedules.\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\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2063},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive remains focused on its original purpose: addressing the specific safety risk of lead-lag bolt corrosion in 369D/H helicopters following a reported failure. It has not expanded beyond this maintenance inspection requirement."},"complexity_factors":["Single-page document with one specific inspection requirement","No defined terms, exemptions, or conditional exceptions","Linear structure with clear applicability limited to two helicopter models (369D and 369H)","Reference to external technical manual (Basic H.M.I.) required to complete the inspection","Simple compliance timeline (100 hours initially, then every 300 hours)"],"plain_english_summary":"This directive requires operators and maintainers of Hughes/Kawasaki 369D and 369H helicopters to inspect the inner bores of lead‑lag (main rotor) bolts for corrosion using the H.M.I. procedures. Corrosion can cause hydrogen embrittlement and bolt failure—one failure occurred in Australia—risking catastrophic rotor loss. Initial inspection is within 100 flight hours after 31 July 1981, repeat every 300 hours, and any corrosion must be repaired per manufacturer instructions."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion","history":"/api/acts/ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion/history","analysis":"/api/acts/ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion/analysis","conflicts":"/api/acts/ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion/conflicts","importantCases":"/api/acts/ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion/important-cases","documents":"/api/acts/ad-hu-369-48-main-rotor-lead-lag-bolts-inspection-for-corrosion/documents"}}