{"id":"F2006B04381","name":"AD/BELL 205/45 Amdt 4 - Main Rotor Yoke","slug":"ad-bell-205-45-amdt-4-main-rotor-yoke","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44206,"registerId":"commonwealth-F2006B04381-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 205/45 Amdt 4 - Main Rotor Yoke","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nBell Helicopter Textron 205 Series Helicopters\n\nAD/BELL 205/45\n\nAmdt 4\n\n  \nMain Rotor Yoke 9/91\n\nApplicability: All helicopters fitted with main rotor yoke P/N 204-011-102- (all dash numbers).\n\nRequirement: 1. Inspect the main rotor yoke in-situ in accordance with the Accomplishment Instructions in Bell Alert SB No. 205-90-36 Revision A, dated 23 March 1990.\n\n2. Remove the yoke assembly from the main rotor hub assembly and inspect the yoke in accordance with FAA AD 79-20-05, Amendment 39-3662.\n\nCompliance: As detailed in the Requirement Documents.\n\nBackground: Amendment 3 implemented the additional inspections of ASB 205-87-28, which was issued as a result of fatigue cracks being found in service. It required that visual inspections of the main rotor yoke be performed daily and every 1200 hours/24 months. These are additional to the more detailed 2400 hourly inspection specified in FAA AD 79-20-05.\n\nAmendment 4 specifies Bell Alert SB 205-90-36 which supersedes Alert SB\n\n205-87-28, and adds an additional yoke spindle inspection at 1200 hours/24 month intervals. Inspections done to amendment 3 may be considered for the purposes of determining when next inspections are due.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of ensuring main rotor yoke airworthiness through inspection. While it updates the specific technical requirements (replacing one service bulletin with another and adding a spindle inspection), it does not expand beyond the original purpose of preventing fatigue crack failures in this specific component."},"complexity_factors":["Short, single-purpose document (1 page)","Only 2 defined part numbers referenced (P/N 204-011-102 and SB numbers)","Simple two-step requirement structure","Minimal conditional logic (only transition provision for Amendment 3 compliance)","Heavy reliance on external documents (FAA AD and Bell service bulletins) which are not reproduced in the text"],"plain_english_summary":"This safety directive requires Bell 205 operators to perform mandated inspections of the main rotor yoke (part 204-011-102), using updated Bell and FAA procedures. Amendment 4 replaces the older service bulletin and adds a spindle inspection every 1,200 flight hours or 24 months.\n\nIt affects all owners/operators of Bell 205s with that yoke and aims to catch fatigue cracks that could cause catastrophic rotor failure; prior compliant inspections under Amendment 3 remain valid."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 4 expands the AD by superseding the earlier Bell Alert (205-87-28) with Bell Alert SB 205-90-36 and adding a 1200‑hour/24‑month spindle inspection. It retains the existing 2400‑hour detailed inspection (FAA AD 79-20-05) and allows prior inspections to be considered when determining next due inspections."},"complexity_factors":["References and dependence on external service documents (Bell Alert SB 205-90-36 and FAA AD 79-20-05) (Requirement)","Multiple overlapping inspection intervals to track (daily, 1200 hours/24 months, 2400 hours) (Background / Requirement)","Different inspection modes: in‑situ inspections versus removal and detailed inspection of the yoke (Requirement)","Crediting prior inspections for scheduling requires historical records and administrative checks (Background)","Technical inspection standards require qualified maintenance personnel and may cause aircraft downtime and repair costs (Requirement)"],"plain_english_summary":"This directive applies to Bell 205 helicopters with main rotor yoke P/N 204-011-102‑(all dash numbers). It requires operators to perform in‑place inspections following Bell Alert SB 205-90-36 and, where directed, remove the yoke for the detailed FAA AD 79-20-05 inspection. Amendment 4 adds a 1200‑hour/24‑month spindle inspection and allows earlier inspections to be credited when scheduling the next check. Operators/owners fund inspections and repairs; CASA requires compliance and enforcement, increasing inspection frequency and record‑keeping."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-205-45-amdt-4-main-rotor-yoke","history":"/api/acts/ad-bell-205-45-amdt-4-main-rotor-yoke/history","analysis":"/api/acts/ad-bell-205-45-amdt-4-main-rotor-yoke/analysis","conflicts":"/api/acts/ad-bell-205-45-amdt-4-main-rotor-yoke/conflicts","importantCases":"/api/acts/ad-bell-205-45-amdt-4-main-rotor-yoke/important-cases","documents":"/api/acts/ad-bell-205-45-amdt-4-main-rotor-yoke/documents"}}