{"id":"F2006B04607","name":"AD/BELL 222/15 - Main Rotor Yoke","slug":"ad-bell-222-15-main-rotor-yoke","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44359,"registerId":"commonwealth-F2006B04607-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 222/15 - Main Rotor Yoke","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)  Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters\n\n \n\nAD/BELL 222/15 Main Rotor Yoke 7/89\n\nApplicability: All helicopters fitted with main rotor yoke P/N 222-011-102-101.\n\n \n\nRequirement: Modify yoke assembly in accordance with Bell Alert Service Bulletin 222-88-51. Compliance:               Prior to issue for Australian Certificate of Airworthiness.\n\nBackground:  Investigation of a cracked main rotor yoke has determined that the crack resulted from fretting. A yoke assembly modification has been developed that will add a buffer pad under the yoke bushings and replace the existing bushings with a larger flange version. The flapping bearing buffer pads are also replaced with larger diameter pads.\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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"No change indicated. The AD targets all helicopters fitted with P/N 222-011-102-101 and mandates the particular yoke modification per Bell Alert Service Bulletin 222-88-51 prior to issue of an Australian Certificate of Airworthiness. The text sets a narrowly targeted corrective action in response to a documented fretting-related crack and does not expand scope beyond that corrective measure."},"complexity_factors":["Narrow applicability: applies only to helicopters fitted with main rotor yoke P/N 222-011-102-101 (Applicability).","Mandated modification must follow a manufacturer Alert Service Bulletin (Requirement), creating dependence on external technical instructions.","Compliance timing is administratively linked to issuance of the Australian Certificate of Airworthiness (Compliance), affecting scheduling and regulatory checks.","Technical intervention: adds buffer pads and replaces bushings and flapping-bearing pads (Background), requiring specific parts and certified maintenance actions.","Verification burden on operators and the regulator at CofA issuance (proof of modification/inspection).","Potential supply and maintenance-cost impacts for owners/operators who must procure parts and perform the modification.","Limited discretion: the AD prescribes a specific fix rather than alternative corrective actions, constraining operator choices."],"plain_english_summary":"Requires a one-off modification of the Bell 222 main rotor yoke (P/N 222-011-102-101) in line with Bell Alert Service Bulletin 222-88-51, to be completed before an Australian Certificate of Airworthiness is issued. The change — adding buffer pads and larger-flange bushings and flapping-bearing pads — responds to a fretting-related crack; owners/operators must arrange and pay for the work and schedule it to obtain the certificate."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific helicopter model. It has not expanded beyond its original purpose of mandating a safety modification to prevent main rotor yoke failures."},"complexity_factors":["Single, specific applicability criterion (one part number)","Single mandatory action with clear reference to external technical document (Bell Alert Service Bulletin)","No defined terms section","No conditional logic or exceptions","Straightforward compliance deadline (prior to airworthiness certification)","Total length: approximately 150 words of substantive content"],"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 does:** It requires a specific safety modification to Bell 222 series helicopters. The fix addresses a dangerous cracking problem in the main rotor yoke (the critical component that connects the rotor blades to the helicopter's mast). The cracking was caused by \"fretting\" — a form of wear damage from repeated rubbing between metal parts.\n\n**Who must comply:** Anyone who operates or maintains a Bell 222 helicopter fitted with main rotor yoke part number 222-011-102-101.\n\n**What must be done:** Install buffer pads under the yoke bushings, replace the existing bushings with larger-flanged versions, and replace the flapping bearing buffer pads with larger diameter ones — following the exact instructions in Bell Alert Service Bulletin 222-88-51.\n\n**When it must be done:** Before the helicopter can be issued with (or continue to hold) an Australian Certificate of Airworthiness — essentially, before it can legally fly in Australia.\n\n**Why it matters:** A cracked main rotor yoke can lead to catastrophic rotor failure and loss of the aircraft. This AD prevents that by mandating a proven engineering fix."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-222-15-main-rotor-yoke","history":"/api/acts/ad-bell-222-15-main-rotor-yoke/history","analysis":"/api/acts/ad-bell-222-15-main-rotor-yoke/analysis","conflicts":"/api/acts/ad-bell-222-15-main-rotor-yoke/conflicts","importantCases":"/api/acts/ad-bell-222-15-main-rotor-yoke/important-cases","documents":"/api/acts/ad-bell-222-15-main-rotor-yoke/documents"}}