{"id":"F2006B04812","name":"AD/BO 105/9 - Main Rotor Blade Grip Bolts","slug":"ad-bo-105-9-main-rotor-blade-grip-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44604,"registerId":"commonwealth-F2006B04812-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BO 105/9 - Main Rotor Blade Grip Bolts","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)  Eurocopter BO 105 Series Helicopters\n\n \n\nAD/BO 105/9 Main Rotor Blade Grip Bolts 7/87\n\nApplicability: All models not fitted with the optional main rotor blade folding system. Requirement: Action in accordance with MBB Telex Alert Service Bulletin No. ASB-BO 105-10-\n\n101 dated 6 May 1987, as amended by Revision 1 dated 8 May 1987, except that\n\ndefective bolts found as a result of the inspection should be forwarded to the nearest Regional Office of the Department.\n\n \n\nCompliance: As detailed in the Requirement Document.\n\n \n\nBackground: Fractures and cracks have been found in the fillet radius under the head of the smaller diameter bolt which attaches the main rotor blade to the grip. Faulty installation during manufacture is the suspected cause.\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\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 discrete, time-bound safety directive issued in 1987 addressing a specific mechanical defect. It has not expanded beyond its original purpose of mandating inspection and reporting for a identified safety-critical hardware failure mode."},"complexity_factors":["Very short document (under 200 words)","Only 1 defined applicability criterion (absence of optional blade-folding system)","Single cross-reference to external technical document (MBB Service Bulletin)","No nested conditions or exceptions","Straightforward compliance pathway: inspect per bulletin, report defects to Department","Minimal legislative drafting — essentially a regulatory notice format rather than complex statutory text"],"plain_english_summary":"This CASA Airworthiness Directive mandates immediate inspection of main rotor blade grip bolts on Eurocopter BO 105 helicopters without the blade‑folding option after discovery of fillet‑radius cracks suspected from faulty installation. Failure could let a blade detach in flight.\n\nAffected operators and maintainers must follow MBB Telex ASB‑BO 105‑10‑101 procedures and report any defective bolts to the Department’s Regional Office."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"No change to scope from the instrument's stated purpose. The AD targets Eurocopter BO 105 series without the optional folding system and mandates inspection and reporting per the referenced MBB Telex ASB to address discovered fractures and cracks (Applicability, Requirement, Background)."},"complexity_factors":["External normative reference: compliance is tied to following MBB Telex Alert Service Bulletin ASB‑BO 105‑10‑101 (Requirement).","Administrative reporting: defective bolts must be forwarded to the nearest Regional Office of the Department (Requirement).","Applicability carve‑out: applies to all BO 105 models not fitted with the optional blade folding system (Applicability).","Delegated compliance detail: timing and procedures are contained in the Requirement Document rather than fully set out in the AD (Compliance).","Technical root cause identified but limited remedy described: Background cites suspected faulty installation during manufacture; AD prescribes inspection/reporting rather than on‑its‑face replacement policy (Background, Requirement).","Operational and cost impact falls on operators: operators must perform inspections and follow the service bulletin, implying maintenance time and parts/repair actions where defects are found (Applicability, Requirement)."],"plain_english_summary":"This airworthiness directive requires operators of Eurocopter BO 105 helicopters (except those fitted with the optional main rotor blade folding system) to inspect the main rotor blade grip bolts and follow the procedures in MBB Telex Alert Service Bulletin ASB‑BO 105‑10‑101 (6–8 May 1987). Any defective bolts found must be forwarded to the nearest Regional Office of the Department. It responds to fractures and cracks discovered under the bolt head that are suspected to result from faulty installation during manufacture."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bo-105-9-main-rotor-blade-grip-bolts","history":"/api/acts/ad-bo-105-9-main-rotor-blade-grip-bolts/history","analysis":"/api/acts/ad-bo-105-9-main-rotor-blade-grip-bolts/analysis","conflicts":"/api/acts/ad-bo-105-9-main-rotor-blade-grip-bolts/conflicts","importantCases":"/api/acts/ad-bo-105-9-main-rotor-blade-grip-bolts/important-cases","documents":"/api/acts/ad-bo-105-9-main-rotor-blade-grip-bolts/documents"}}