{"id":"F2006B06210","name":"AD/PHZL/37 - Hard Alloy Blades - Inspection","slug":"ad-phzl-37-hard-alloy-blades-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47098,"registerId":"commonwealth-F2006B06210-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/37 - Hard Alloy Blades - Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPropellers \\- Variable Pitch \\- Hartzell\n\nAD/PHZL/37 Hard Alloy Blades \\- Inspection 7/74\n\nApplicability: All blades identified with the letter “H” after the blade design number as follows: T10173H( )-( ), T10176H( )-( ), T10178H( )-( ) and T10282H ( )-( ), excluding the\n\nfollowing Serial numbered propellers:\n\nHC-B3TN-2, S/N AG-275 and above. HC-B3TN-3, S/N BU-4624 and above.\n\nHC-B3TN-5, S/N BV-2210, BV-2213, BV-2214, BV-2216 and above.\n\nHC-B3TN-7, S/N CV-7 and above. HC-B3TF-7, S/N EX-3 and above. HC-B4TN-3, S/N EA-255 and above. HC-B4TN-5, S/N CD-62 and above.\n\nDocument: Hartzell SB No. 105A.\n\nCompliance: For blades with less than 1000 hours time in service, within 100 hours time in service after 31 July 1974.\n\nNote: Blades with more than 1000 hours time in service are not affected by this Directive.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope is clear and narrow in the source text: it applies only to the listed Hartzell blade part numbers with an “H” suffix, excludes specified serial-number ranges, and applies only to blades with less than 1,000 hours TIS (Applicability; Note). The directive does not expand or contract that scope elsewhere in the text provided; it also sets a single time window for compliance for affected blades (Compliance)."},"complexity_factors":["Narrow technical identification: specific blade design numbers with an “H” suffix and multiple serial-number exclusions (Applicability).","Time-based compliance window tied to individual blade hours (Compliance, Note).","Cross-reference to an external manufacturer document (Hartzell SB No. 105A) for inspection procedure rather than prescribing procedures in the directive itself (Document).","Lack of remedial steps in the directive: directive requires inspection but does not specify corrective actions to follow if defects are found (Document, implicit).","Administrative burden of verifying part numbers, serial numbers and time-in-service records to determine applicability (Applicability, Compliance)."],"plain_english_summary":"This AD requires operators and maintenance organisations to inspect specific Hartzell alloy propeller blades identified by an “H” suffix (with some serial-number ranges excluded) if each blade has under 1,000 hours TIS. Inspections must follow Hartzell Service Bulletin No. 105A and be completed within 100 hours TIS after 31 July 1974, imposing scheduling, record-checking and inspection costs on affected operators."},"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 narrow, specific scope. It has not expanded beyond its original purpose of inspecting specific Hartzell propeller blades for a identified safety concern."},"complexity_factors":["Single, specific technical requirement (visual inspection)","Clear applicability criteria using model numbers and serial number cut-offs","Simple binary compliance condition (hours-based exemption)","No defined terms section, no cross-references to other legislation","Short document (approximately 150 words)","Single compliance deadline with straightforward calculation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Hartzell aircraft propeller blades to conduct inspections.\n\n**What it does:**\n- Orders visual inspections of certain \"hard alloy\" propeller blades made by Hartzell\n- These blades are identified by having an \"H\" in their model number (specific models listed: T10173H, T10176H, T10178H, and T10282H series)\n\n**Who it affects:**\n- Aircraft owners, operators, and maintenance organisations using these specific Hartzell propeller blades\n- Exemptions apply to newer propellers with serial numbers above certain thresholds (these were manufactured with improved designs)\n\n**The safety issue:**\n- The directive references Hartzell Service Bulletin 105A, suggesting a potential defect or wear pattern in these blades that could compromise flight safety\n\n**Compliance deadline:**\n- For blades with **less than 1,000 flight hours**: inspect within 100 flight hours after 31 July 1974\n- Blades with **more than 1,000 flight hours** are exempt (presumably because they've already proven durability or the defect manifests early)\n\n**Why it matters:**\nPropeller blade failures can cause catastrophic accidents. This directive ensures potentially defective blades are identified before they fail, protecting pilots, passengers, and people on the ground."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-37-hard-alloy-blades-inspection","history":"/api/acts/ad-phzl-37-hard-alloy-blades-inspection/history","analysis":"/api/acts/ad-phzl-37-hard-alloy-blades-inspection/analysis","conflicts":"/api/acts/ad-phzl-37-hard-alloy-blades-inspection/conflicts","importantCases":"/api/acts/ad-phzl-37-hard-alloy-blades-inspection/important-cases","documents":"/api/acts/ad-phzl-37-hard-alloy-blades-inspection/documents"}}