{"id":"F2006B01816","name":"AD/A109/30 - Gleason Crown Inspection","slug":"ad-a109-30-gleason-crown-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41014,"registerId":"commonwealth-F2006B01816-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A109/30 - Gleason Crown Inspection","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)  \nAgusta A109 Series Helicopters\n\nAD/A109/30 Gleason Crown Inspection 8/99 DM\n\nApplicability: A109A, A109AII and A109C helicopters, fitted with main transmission and Gleason Crown identified in Agusta Service Bulletin No. 109-109 dated 03 June 1999 and which have accumulated between 300 and 900 operating hours.\n\nRequirement: 1. Perform the aural inspection of the main gearbox in accordance with the instructions contained in Part I of Agusta Service Bulletin No. 109-109 dated 03 June 1999.\n\nNote: The word “auscultate” in the Agusta SB means “to listen to using a stethoscope”.\n\n    2. Perform the non destructive test of the Gleason Crown (installed in the main transmission) in accordance with the instructions contained in Part II of Agusta Service Bulletin No. 109-109 dated 03 June 1999. Replace Gleason Crown as required by Agusta Service Bulletin No. 109-109.\n\n    3. Repeat the test at 2 above.\n\nNote: RAI AD 99-267 dated 10 June 1999 refers.\n\nCompliance: 1. Before next flight after the effective date of this Directive.\n\n    2. Not later than 50 operating hours following the effective date of this Directive.\n\n    3. Every three hundred operating hours up to and including nine hundred operating hours.\n\nThis Airworthiness Directive becomes effective on 14 July 1999.\n\nBackground: One case of a cracked Gleason Crown on an Agusta A109C helicopter has been discovered following an investigation into a reported unusual noise from the main rotor transmission system. This directive introduces a regular aural inspection and Non Destructive test to monitor for the presence of cracks in the Gleason Crown of certain helicopters and certain transmissions.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, targeted Airworthiness Directive issued in response to a specific safety incident (cracked Gleason Crown discovery). It remains tightly scoped to the particular mechanical issue and affected helicopter models. No scope creep is evident."},"complexity_factors":["Single, specific mechanical component targeted (Gleason Crown)","Clear, sequential numbered requirements (only 3 main requirements)","Simple conditional applicability (3 criteria: model type, service bulletin reference, flight hours between 300-900)","Straightforward compliance timeline (before next flight, within 50 hours, then every 300 hours)","Minimal cross-referencing (only references one Agusta Service Bulletin and one related FAA directive)","No nested exceptions or complex definitional sections","Plain language note explaining technical term \"auscultate\""],"plain_english_summary":"CASA requires owners/operators of certain Agusta A109A, A109AII and A109C helicopters (with specified main transmissions) to inspect the Gleason Crown in the main gearbox for cracks. The rule targets aircraft between 300 and 900 total hours after a cracked crown was found, which risks loss of main rotor power.\n\nInspections include an immediate aural check, crack-detection testing soon after, and repeating periodic tests until the helicopter reaches 900 hours to catch and replace cracked crowns."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive defines a narrowly targeted scope: specified A109 variants fitted with the Gleason Crown identified in the referenced service bulletin and with 300–900 operating hours. It introduces mandatory inspections and NDTs for that cohort but does not expand applicability beyond those models, parts or the stated operating‑hour window."},"complexity_factors":["Targeted applicability to specific helicopter models and to Gleason Crowns identified in Agusta Service Bulletin No. 109-109 (Applicability).","Mandates actions but defers procedural detail to an external document (Agusta Service Bulletin Part I & II) — reliance on a service bulletin increases implementation dependency.","Multiple, staggered compliance deadlines: before next flight (aural), within 50 operating hours (first NDT), and every 300 operating hours up to 900 hours (Compliance).","Technical requirement for non‑destructive testing and conditional replacement of the Gleason Crown (Requirement) — requires specialist maintenance capability and parts availability.","Clarifying note on terminology ('auscultate' = listen with stethoscope) reduces interpretive ambiguity for the aural inspection (Requirement, Note).","Limited temporal scope tied to accumulated operating hours (300–900) creates a cohorting rule that operators must verify against aircraft records (Applicability).","Cross-reference to RAI AD 99-267 may require checking related directives for consistency (Requirement, Note).","Operational burden falls on operators/owners (scheduling, costs, downtime) rather than regulator; no discretionary carve-outs or alternative means are provided in the text (Requirement/Compliance)."],"plain_english_summary":"**What it does:** This directive requires operators of Agusta A109A, A109AII and A109C helicopters fitted with the Gleason Crown identified in Agusta Service Bulletin No. 109-109 to perform an immediate aural inspection, a non‑destructive test within 50 operating hours, and repeat NDTs every 300 hours up to 900 hours, replacing the crown if cracks are found. It affects owners/operators who must fund and schedule the inspections and any replacements to detect transmission‑crown cracks and reduce failure risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a109-30-gleason-crown-inspection","history":"/api/acts/ad-a109-30-gleason-crown-inspection/history","analysis":"/api/acts/ad-a109-30-gleason-crown-inspection/analysis","conflicts":"/api/acts/ad-a109-30-gleason-crown-inspection/conflicts","importantCases":"/api/acts/ad-a109-30-gleason-crown-inspection/important-cases","documents":"/api/acts/ad-a109-30-gleason-crown-inspection/documents"}}