{"id":"F2006B06208","name":"AD/PHZL/32 - Propeller Modification - Installation of Spring Back-up Kit","slug":"ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47094,"registerId":"commonwealth-F2006B06208-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/32 - Propeller Modification - Installation of Spring Back-up Kit","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/32 Propeller Modification - Installation\n\nof Spring Back-up Kit\n\n\n7/72\n\n \n\nApplicability: Models HC-E2YK-2RB, HC-E2YR-2RB and HC-E2YL-2( ) propellers fitted with 8465-7R, 7663-4 or J7663-4 non counterweighted blades.\n\n \n\nDocument: 1. Hartzell SL No. 62; or\n\n \n\n2. FAA AD 71-21-9.\n\n \n\nCompliance: At next reconditioning completed after 29 September, 1972.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The directive imposes a new mandatory maintenance/modification obligation for the listed propeller models when fitted with the specified non-counterweighted blades by requiring installation of a spring back-up kit (Applicability; Compliance). The directive therefore changes the maintenance obligations applicable to owners/operators of those propellers by adding a specific modification requirement to be completed at the next reconditioning after 29 September 1972 (Compliance)."},"complexity_factors":["Narrow technical scope: applies only to specific Hartzell propeller models and specific blade part numbers (Applicability).","Key procedural and technical details are external: compliance requires consulting Hartzell SL No. 62 or FAA AD 71-21-9 for exact instructions and parts (Document).","Time-based compliance rule tied to maintenance events: obligation is deferred until the next reconditioning after a specified historical date, which requires operators to interpret maintenance schedules (Compliance).","Minimal procedural detail in the text: no penalty, no alternative compliance path, and no parts/labour estimates included (Document; Compliance).","Technical terminology (model and part numbers) requires expert interpretation by maintenance personnel and regulators (Applicability)."],"plain_english_summary":"This Airworthiness Directive requires installation of a spring back-up kit on specified Hartzell variable‑pitch propellers (models HC‑E2YK‑2RB, HC‑E2YR‑2RB, HC‑E2YL‑2( )) when fitted with listed non‑counterweighted blades, to be done at the next propeller reconditioning completed after 29 September 1972. It affects owners/operators of those propellers (who will bear kit and installation costs); technical instructions are in Hartzell Service Letter No. 62 or FAA AD 71‑21‑9."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1972. It has not expanded beyond its original narrow purpose of mandating a specific hardware modification to specific propeller models."},"complexity_factors":["Very short document (approximately 150 words)","Only 3 defined model numbers and 3 blade types in applicability section","Single compliance requirement with clear deadline","No nested exceptions or conditional logic","No cross-references to other legislation beyond two source documents","Straightforward imperative structure: 'do X by Y date'"],"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 or operators of specific Hartzell propeller models to install a 'spring back-up kit' to prevent mechanical failure.\n\n**Who it affects:**\n- Aircraft fitted with specific Hartzell variable-pitch propeller models: **HC-E2YK-2RB, HC-E2YR-2RB, and HC-E2YL-2( )**\n- Specifically those using blade types: **8465-7R, 7663-4, or J7663-4** (non-counterweighted blades)\n\n**What it requires:**\n- Installation of a spring back-up kit (a mechanical safety backup) as detailed in Hartzell Service Letter No. 62 or the equivalent US FAA directive (AD 71-21-9)\n\n**When it must be done:**\n- By the **next reconditioning** of the propeller after **29 September 1972**\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety mandates. Non-compliance means the aircraft cannot legally fly. This particular directive addresses a design flaw in certain propeller blades that could lead to catastrophic failure if not corrected."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit","history":"/api/acts/ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit/history","analysis":"/api/acts/ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit/analysis","conflicts":"/api/acts/ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit/conflicts","importantCases":"/api/acts/ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit/important-cases","documents":"/api/acts/ad-phzl-32-propeller-modification-installation-of-spring-back-up-kit/documents"}}