{"id":"F2006B01832","name":"AD/A109/47 - Main Rotor Head Damper","slug":"ad-a109-47-main-rotor-head-damper","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41030,"registerId":"commonwealth-F2006B01832-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nAgusta A109 Series Helicopters","sortOrder":0},{"sectionNumber":"AD/A109/47 Main Rotor Head Damper 11/200","sectionType":"part","heading":"AD/A109/47 Main Rotor Head Damper 11/2003 DM","content":"# AD/A109/47 Main Rotor Head Damper 11/2003 DM\n\nApplicability: All Model a 109E helicopters with dampers part number 109-0111-06-103 fitted with Microtechnica rod-end assemblies part number 3637GR85.\n\nRequirement: Inspect in accordance with Agusta Technical Bulletin No. 109EP-37 Revision A.\n\nNote: ENAC AD 2003-249 refers.\n\nCompliance: For Part I of the Requirement document: Within 25 flight hours after 10 September 2003, unless already accomplished.\n\nFor Part II of the Requirement document: Within 25 flight hours after accomplishment of Part I of the Requirement document.\n\nThis Airworthiness Directive becomes effective on 10 September 2003.\n\nBackground: The manufacturer received reports of fractures of the main rotor head damper rod end.\n\nInvestigation revealed fatigue failure originating from the rod-end thread under cut.\n\n![](image.002.png)  \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 4 September 2003\n\n![](image.001.png)","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: addressing a specific unsafe condition in a specific helicopter model with specific part configurations. There is no evidence of scope creep."},"complexity_factors":["Very short document (approximately 250 words)","Only 2 defined part numbers in the applicability section","Single requirement referencing an external technical document (Agusta Technical Bulletin)","Simple two-stage compliance structure (Part I and Part II)","No nested exceptions or conditional logic","Straightforward background explaining the safety issue","Clear effective date and compliance deadlines"],"plain_english_summary":"CASA requires owners/operators of Agusta A109E helicopters fitted with damper part 109-0111-06-103 (Microtechnica rod-end 3637GR85) to inspect the main rotor head damper rod-ends for fatigue cracks, following Agusta Technical Bulletin 109EP-37 Rev A. The first inspection was due within 25 flight hours after 10 Sept 2003, with a repeat within 25 flight hours after the first.\n\nThe order responds to discovered thread under‑cut fatigue fractures that could cause damper failure and catastrophic loss of control; it became legally enforceable 10 Sept 2003."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies to all Agusta A109E helicopters fitted with the specified damper and Microtechnica rod-end assemblies and mandates inspection per the manufacturer's technical bulletin within set flight-hour windows. The text limits applicability to that configuration and addresses the stated rod-end fatigue issue; there is no apparent expansion or narrowing of scope beyond the stated safety concern."},"complexity_factors":["Technical specificity: applicability limited to A109E helicopters fitted with a particular damper part number (109-0111-06-103) and a specific rod-end assembly (Microtechnica P/N 3637GR85) (Applicability).","External reference: compliance requires following Agusta Technical Bulletin No. 109EP-37 Revision A, creating dependency on an external document (Requirement).","Staged compliance: Requirement document is split into Part I and Part II with sequential timing (Part II due within 25 flight hours after Part I) (Compliance).","Short compliance windows: inspections must be completed within 25 flight hours after the AD effective date or after Part I, increasing operational scheduling pressure (Compliance).","Regulatory basis and enforceability: issued under CASR 1998 subregulation 39.1(1) and given an effective date, creating mandatory legal obligations (preamble/first paragraph and Effective date).","Operational burden: operators must organise inspections and any corrective action at their expense; the AD does not prescribe cost allocation or funding (Requirement/Compliance).","Safety evidence linkage: the AD is tied to a specific failure mode (fatigue from thread undercut) identified in the Background, which constrains remedial measures to inspection/repair."],"plain_english_summary":"This Airworthiness Directive requires operators of Agusta A109E helicopters fitted with damper P/N 109-0111-06-103 and Microtechnica rod-end assemblies P/N 3637GR85 to inspect the main rotor head damper per Agusta Technical Bulletin 109EP-37 Rev A within short, specified flight‑hour windows. CASA issued the AD after reports of rod‑end fractures caused by fatigue originating at a thread undercut. Operators pay for inspections and any corrective work; the AD prescribes mandatory timing and refers operators to the manufacturer’s inspection instructions."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-a109-47-main-rotor-head-damper","history":"/api/acts/ad-a109-47-main-rotor-head-damper/history","analysis":"/api/acts/ad-a109-47-main-rotor-head-damper/analysis","conflicts":"/api/acts/ad-a109-47-main-rotor-head-damper/conflicts","importantCases":"/api/acts/ad-a109-47-main-rotor-head-damper/important-cases","documents":"/api/acts/ad-a109-47-main-rotor-head-damper/documents"}}