{"id":"F2006B02591","name":"AD/B-2/2 - Tail Rotor Drive - Modification","slug":"ad-b-2-2-tail-rotor-drive-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41848,"registerId":"commonwealth-F2006B02591-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B-2/2 - Tail Rotor Drive - Modification","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-2/2 Tail Rotor Drive - Modification 12/60\n\nApplicability: All model B-2 prior to S/Nos. 32. Document: Brantly SB No. 2.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive. It has not expanded beyond its original purpose of addressing a specific airworthiness issue in early Brantly B-2 helicopters. The scope remains precisely limited to the tail rotor drive modification for the specified serial numbers."},"complexity_factors":["Extremely short document (under 100 words of substantive content)","Only 2 defined applicability criteria (model type and serial number range)","Single compliance requirement with no conditional exceptions","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","No nested definitions or interpretive provisions","Straightforward command structure: 'applies to X, do Y, do it now'"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific helicopters.\n\n**What it does:**\n- Requires owners and operators of **Brantly B-2 series helicopters** (specifically those with serial numbers before No. 32) to modify the **tail rotor drive system**.\n- The modification must follow the manufacturer's Service Bulletin No. 2.\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains early-model Brantly B-2 helicopters (serial numbers 1–31).\n\n**Why it matters:**\n- **Safety-critical:** The tail rotor keeps the helicopter from spinning uncontrollably. A failure here is catastrophic.\n- **Immediate action required:** \"Forthwith\" means do it now — not at the next scheduled maintenance.\n- **Legally binding:** Non-compliance grounds the aircraft (you cannot legally fly until fixed).\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A compulsory safety fix issued when a design flaw or unsafe condition is discovered.\n- **Service Bulletin (SB):** Manufacturer's official instructions for repairs or modifications.\n- **Forthwith:** Immediately, without delay."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD, as presented, sets a single, specific obligation: require a tail-rotor drive modification on all Brantly B-2 helicopters with serial numbers prior to 32, to be carried out according to Brantly SB No. 2 and completed forthwith. There is no text in the instrument indicating an expansion or narrowing of that group or a change from an earlier stated scope; therefore the scope appears consistent with the instrument's explicit applicability statement (Applicability) and does not show evidence of change from the instrument's stated purpose."},"complexity_factors":["Narrow and specific applicability (only Brantly B-2 with S/Ns prior to 32)","Immediate compliance requirement ('Forthwith')","Reliance on an external document (Brantly SB No. 2) for technical implementation","Minimal procedural or penalty detail within the AD text itself","Regulatory context identified (Civil Aviation Regulations 1998, Part 39) but no enforcement mechanics set out in the AD text"],"plain_english_summary":"This AD requires immediate modification of the tail‑rotor drive on Brantly B‑2 helicopters with serial numbers prior to 32, to be carried out according to Brantly SB No. 2. Compliance is \"forthwith\" and the AD is issued by CASA under the Civil Aviation Regulations 1998, Part 39.\n\nAffected owners/operators must arrange and pay for the work (parts, labour, downtime); maintenance providers must perform it to the referenced service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b-2-2-tail-rotor-drive-modification","history":"/api/acts/ad-b-2-2-tail-rotor-drive-modification/history","analysis":"/api/acts/ad-b-2-2-tail-rotor-drive-modification/analysis","conflicts":"/api/acts/ad-b-2-2-tail-rotor-drive-modification/conflicts","importantCases":"/api/acts/ad-b-2-2-tail-rotor-drive-modification/important-cases","documents":"/api/acts/ad-b-2-2-tail-rotor-drive-modification/documents"}}