{"id":"F2006B04517","name":"AD/BELL 206/63 - Horizontal Stabilizer - Modification","slug":"ad-bell-206-63-horizontal-stabilizer-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114225,"registerId":"commonwealth-F2006B04517-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/63 - Horizontal Stabilizer - 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\nBell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\n \n\nAD/BELL 206/63 Horizontal Stabilizer - Modification 10/74\n\nApplicability: All models 206A and 206B with S/Nos. 1 to 1251 except those which have incorporated Bell Kit P/N 206-704-096-3.\n\n \n\nDocument: Bell SB No. 206-01-74-1, Rev. B.\n\n \n\nCompliance: Within 100 hours time in service after 31 October 1974.\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 from 1974 with a single specific purpose. It has not expanded beyond its original scope of requiring a stabilizer modification on specific helicopter models."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: applicability range, exception, reference document, and compliance deadline","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Single, unambiguous compliance action with clear deadline","No conditional logic or nested exceptions — only one straightforward exclusion (the Bell Kit)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it requires:** Owners and operators of specific Bell 206 helicopters must modify the **horizontal stabilizer** (the small wing at the tail that keeps the helicopter level in flight). The modification must be done according to Bell Helicopter's Service Bulletin 206-01-74-1, Revision B.\n\n**Which helicopters are affected:**\n- **Bell 206A and 206B models**\n- **Serial numbers 1 through 1251**\n- **Exception:** Helicopters that already have Bell Kit part number 206-704-096-3 installed don't need to do this\n\n**Deadline:** The work must be completed within **100 hours of flight time** after 31 October 1974.\n\n**Why it matters:** Airworthiness Directives are legally binding safety fixes. They typically address design flaws, fatigue issues, or other problems that could cause accidents. Failing to comply means the aircraft cannot legally fly in Australia. This particular AD from 1974 addressed a known issue with the horizontal stabilizer that could affect flight safety."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument itself sets a single mandatory modification, cites the governing service bulletin and specifies a compliance window and a single exception. The supplied text contains no indication that the AD’s scope was altered from any earlier or original statement; it defines the affected aircraft and the required action without showing scope changes."},"complexity_factors":["Narrow technical scope: applies only to Bell 206A and 206B with S/N 1–1251 (Applicability).","Single external technical reference: requires following Bell SB No. 206-01-74-1, Rev. B (Document).","Simple temporal requirement: one fixed compliance window (100 hours after 31 Oct 1974) (Compliance).","One specific exception (kits with P/N 206-704-096-3) reduces scope but requires record checks (Applicability).","No discretionary relief or procedural complexity in the text—compliance is mandatory and binary (Applicability; Compliance)."],"plain_english_summary":"This Airworthiness Directive mandates a specific horizontal-stabilizer modification for Bell 206A/206B helicopters serial nos. 1–1251, unless Bell Kit P/N 206‑704‑096‑3 is already fitted. Work must follow Bell Service Bulletin No. 206‑01‑74‑1, Rev. B and was required within 100 hours TIS after 31 Oct 1974. Owners/operators are responsible for arranging, paying for, and documenting compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-63-horizontal-stabilizer-modification","history":"/api/acts/ad-bell-206-63-horizontal-stabilizer-modification/history","analysis":"/api/acts/ad-bell-206-63-horizontal-stabilizer-modification/analysis","conflicts":"/api/acts/ad-bell-206-63-horizontal-stabilizer-modification/conflicts","importantCases":"/api/acts/ad-bell-206-63-horizontal-stabilizer-modification/important-cases","documents":"/api/acts/ad-bell-206-63-horizontal-stabilizer-modification/documents"}}