{"id":"F2006B04389","name":"AD/BELL 205/53 - Main Rotor Pillow Block","slug":"ad-bell-205-53-main-rotor-pillow-block","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44214,"registerId":"commonwealth-F2006B04389-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 205/53 - Main Rotor Pillow Block","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 205 Series Helicopters\n\n \n\nAD/BELL 205/53 Main Rotor Pillow Block 7/87\n\nDM\n\n \n\nApplicability: All model 205A and 205A-1 helicopters S/No 30001 to 30332. Requirement:  Action in accordance with Bell Alert SB No 205-87-25.\n\nCompliance: Part 1 of Requirement Document: Within 25 hours time in service after 15 May 1987 and thereafter at intervals not exceeding 25 hours time in service until modified in accordance with Part II of the Requirement document.\n\n \n\nPart II of Requirement Document: Within 300 hours time in service after 15 May 1987 or before 30 June 1987 whichever occurs first.\n\n \n\nBackground: The manufacturer has determined that a contributing factor in the recent failure of a pillow block was loss of torque on the retaining nut.\n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1353},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope addressing the specific safety defect in the main rotor pillow block retaining nut torque on the specified helicopter models."},"complexity_factors":["Refers to external technical document (Bell Alert SB No 205-87-25) without reproducing its contents","Two-part compliance schedule with alternative deadlines ('whichever occurs first')","Technical aviation terminology requiring domain knowledge (e.g., 'time in service', 'pillow block')"],"plain_english_summary":"This directive orders owners and operators of specific Bell 205 helicopters to inspect and modify the **main rotor pillow block** (a bearing housing that supports the rotor shaft) to prevent catastrophic failure.\n\n**Who is affected:** Anyone operating Bell 205A or 205A-1 helicopters with serial numbers 30001 through 30332.\n\n**What must be done:** Follow the manufacturer's safety bulletin (Alert SB No 205-87-25) in two stages:\n* **Part 1:** Inspect the pillow block retaining nut torque every 25 flight hours until the modification is complete\n* **Part 2:** Complete the permanent modification within 300 flight hours (or by 30 June 1987, whichever comes first)\n\n**Why it matters:** A helicopter lost its main rotor because the pillow block retaining nut came loose. This directive prevents the same deadly failure from happening again."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-205-53-main-rotor-pillow-block","history":"/api/acts/ad-bell-205-53-main-rotor-pillow-block/history","analysis":"/api/acts/ad-bell-205-53-main-rotor-pillow-block/analysis","conflicts":"/api/acts/ad-bell-205-53-main-rotor-pillow-block/conflicts","importantCases":"/api/acts/ad-bell-205-53-main-rotor-pillow-block/important-cases","documents":"/api/acts/ad-bell-205-53-main-rotor-pillow-block/documents"}}