{"id":"F2006B02610","name":"AD/B-2/9 - Main Transmission Mount - Reinforcement","slug":"ad-b-2-9-main-transmission-mount-reinforcement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41926,"registerId":"commonwealth-F2006B02610-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B-2/9 - Main Transmission Mount - Reinforcement","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)  Brantly B-2 Series Helicopters\n\n \n\nAD/B-2/9 Main Transmission Mount - Reinforcement 12/60\n\nApplicability: Model B-2 with S/Nos. 4, 5, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17 and 18. Document:  Brantly SL No. 5.\n\nCompliance: Forthwith.\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\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":1872},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope: addressing a specific structural defect in identified Brantly B-2 helicopters. It has not expanded to cover other models, components, or operational scenarios."},"complexity_factors":["Single, unambiguous compliance requirement","No defined terms or interpretation sections","Immediate effect with no conditional triggers or exceptions","Specific applicability limited to 13 identified serial numbers","External technical reference to manufacturer service letter"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations.\n\n**What it requires:** Owners of specific Brantly B-2 helicopters (serial numbers 4, 5, 7–12, and 14–18) must immediately reinforce the main transmission mount. The work must follow the manufacturer's Service Letter No. 5.\n\n**Why it matters:** The main transmission mount attaches the helicopter's gearbox to the airframe. A failure here could cause the rotor system to separate from the aircraft. This directive fixes a known structural weakness in early production models to prevent catastrophic accidents.\n\n**Who must comply:** Anyone operating the listed helicopter serial numbers. The directive takes effect immediately (\"forthwith\") — there is no grace period."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b-2-9-main-transmission-mount-reinforcement","history":"/api/acts/ad-b-2-9-main-transmission-mount-reinforcement/history","analysis":"/api/acts/ad-b-2-9-main-transmission-mount-reinforcement/analysis","conflicts":"/api/acts/ad-b-2-9-main-transmission-mount-reinforcement/conflicts","importantCases":"/api/acts/ad-b-2-9-main-transmission-mount-reinforcement/important-cases","documents":"/api/acts/ad-b-2-9-main-transmission-mount-reinforcement/documents"}}