{"id":"F2006B06236","name":"AD/PHZL/8 - Hub Spider - Replacement","slug":"ad-phzl-8-hub-spider-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47180,"registerId":"commonwealth-F2006B06236-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/8 - Hub Spider - Replacement","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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Propellers - Variable Pitch - Hartzell\n\n \n\nAD/PHZL/8 Hub Spider - Replacement NK\n\nApplicability: All HC12X20 models.\n\n \n\nRequirement: 1. Replace all Hartzell hub spiders having S/Nos. as follows: 1 to 4303, 4307 to 4316, 4318, 4319, 4321, 4323, 4324, 4325, 4328, 4329, 4332 to 4336 and 4341.\n\n \n\n2. Hub spiders with S/nos. other than those listed above may be used as replacements; or\n\n \n\nFAA AD 59-26-1; or ANO 107.1.11.0.1.7.\n\nCompliance: Before installation in an aircraft.\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 addressing a specific known defect in a specific propeller model. It has not expanded beyond its original purpose of mandating replacement of defective hub spiders."},"complexity_factors":["Single, specific mechanical component targeted (hub spider)","Clear serial number list with explicit ranges and individual numbers","Simple binary applicability (all HC12X20 models)","Straightforward compliance timing (before installation)","Only two alternative compliance pathways referenced","No nested definitions, conditional logic, or cross-references to other legislation sections","Document is essentially a 1-page safety bulletin format"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority (CASA) for certain aircraft propellers made by Hartzell.\n\n**What it does:**\n- **Targets:** All HC12X20 model propellers with specific serial numbers on their \"hub spiders\" (a critical component that connects the propeller blades to the hub).\n- **Requires:** Owners and operators must replace hub spiders with serial numbers between 1-4303, 4307-4316, 4318, 4319, 4321, 4323-4325, 4328, 4329, 4332-4336, and 4341.\n- **Alternative compliance:** You can also comply by following an equivalent American FAA directive (AD 59-26-1) or an older Australian order (ANO 107.1.11.0.1.7).\n- **When:** Before the propeller is installed in any aircraft.\n\n**Who it affects:** Aircraft owners, maintenance engineers, and operators using Hartzell HC12X20 variable-pitch propellers.\n\n**Why it matters:** Hub spiders are structural components. This directive prevents potentially dangerous propeller failures by removing suspect parts from service before they can cause accidents."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD itself does not indicate any amendment history or a change of scope within the supplied text. It sets a clear scope: it applies to all HC12X20 models and requires replacement of hub spiders with the listed serial numbers prior to installation, while permitting the listed alternative compliance paths."},"complexity_factors":["Enumerated list of specific serial numbers that must be checked and replaced (Requirement 1)","Presence of multiple alternative compliance paths that reference external directives (FAA AD 59-26-1; ANO 107.1.11.0.1.7) rather than only listing acceptable parts (Requirement 2)","Applicability to an entire model family (All HC12X20 models) requiring fleet-wide verification (Applicability)","Timing requirement limited to 'before installation' without specifying removal deadlines for parts already in service (Compliance)","Operational verification step implied: maintenance records/part identification must be consulted to confirm S/Ns prior to installation (Requirement 1; Compliance)"],"plain_english_summary":"This AD prohibits installation of certain Hartzell HC12X20 propeller hub spiders identified by listed serial numbers, requiring operators and maintenance organisations to replace any such hub spider before it is fitted. \n\nAffected operators must either install a hub spider with a non‑listed serial number or comply with FAA AD 59‑26‑1 or ANO 107.1.11.0.1.7 as an alternative, with attendant procurement, installation and scheduling costs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-8-hub-spider-replacement","history":"/api/acts/ad-phzl-8-hub-spider-replacement/history","analysis":"/api/acts/ad-phzl-8-hub-spider-replacement/analysis","conflicts":"/api/acts/ad-phzl-8-hub-spider-replacement/conflicts","importantCases":"/api/acts/ad-phzl-8-hub-spider-replacement/important-cases","documents":"/api/acts/ad-phzl-8-hub-spider-replacement/documents"}}