{"id":"F2006B06229","name":"AD/PHZL/72 - Counterweight Clamp Bolt Hole","slug":"ad-phzl-72-counterweight-clamp-bolt-hole","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47158,"registerId":"commonwealth-F2006B06229-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/72 - Counterweight Clamp Bolt Hole","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/72 Counterweight Clamp Bolt Hole 12/98\n\nApplicability: Hartzell Propeller Inc. HC-E4A-3(A,I,J) series propellers, with serial numbers HJ1 through HJ1040, that have been previously overhauled or have had a counterweight clamp bolt removed for any reason.\n\nRequirement: Unless previously accomplished:\n\nPerform a one time inspection of the propeller blade counterweight clamps for thread damage in the bolt holes in accordance the Accomplished Instructions of the Hartzell Propeller Inc. Alert Service Bulletin (ASB) No. HC-ASB-61-237, dated 17 July,1998. The replacement or re-assembly of propeller blade counterweight clamps is to be carried out in accordance with ASB No. HC-ASB-61-237, dated 17 July 1998.\n\nCompliance: 1. For propellers with 2,500 or more hours time in service (TIS) since last overhaul, inspect within 300 hours TIS, or 45 days after the effective date of this AD, whichever occurs first.\n\n2. For all other propellers inspect within 600 hours TIS, or 90 days after the effective date of this AD, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 5 November 1998.\n\nBackground: There has been previous reports of thread damage caused by bolt hole failure and thread damage by cross threading, this damage has lead to counterweight separation in flight.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope matches its stated purpose: inspect the specified serial range of HC‑E4A‑3 propellers that were overhauled or had the clamp bolt removed to address reported thread/bolt‑hole failures leading to counterweight separation (Applicability; Requirement; Background). No expansion or narrowing of the affected population is indicated in the text."},"complexity_factors":["Narrow applicability: specific model and serial range (Hartzell HC‑E4A‑3(A,I,J); serials HJ1–HJ1040) — limits population but requires serial checks (Applicability).","Conditional trigger: only applies if propeller was previously overhauled or had the counterweight clamp bolt removed — requires accurate maintenance history (Applicability).","Variable compliance windows tied to time‑in‑service (TIS) since last overhaul — two different schedules (≥2,500 hours vs. others) create scheduling complexity (Compliance).","Technical procedure delegated to manufacturer document (Hartzell ASB HC‑ASB‑61‑237) — agencies require adherence to external technical instructions (Requirement).","Who bears costs: owners/operators must arrange inspection and any replacement/re‑assembly, so direct maintenance cost and aircraft downtime fall on them (Requirement / Compliance).","Compliance burden concentrated in maintenance providers: shops must perform inspections to ASB standard and maintain records, potentially creating short‑term workload peaks (Requirement / Compliance).","Short deadlines for higher‑TIS units (300 hours or 45 days) can create scheduling pressure and substitution effects (operators may defer other work or prioritize affected aircraft) (Compliance).","Administrative clarity: the AD prescribes a specific one‑time action and method reference, leaving limited regulator discretion on how to comply but relying on ASB detail for technical choices (Requirement)."],"plain_english_summary":"Requires a one‑time inspection of counterweight clamp bolt holes for thread damage on Hartzell HC‑E4A‑3(A,I,J) propellers (serials HJ1–HJ1040) that have been overhauled or had the counterweight clamp bolt removed. Inspections and any replacement/re‑assembly must follow Hartzell Alert Service Bulletin HC‑ASB‑61‑237.\n\nCompliance deadlines depend on time‑in‑service since last overhaul: ≥2,500 hours — inspect within 300 hours or 45 days; all others — inspect within 600 hours or 90 days. The stated aim is to prevent counterweight separation caused by thread/bolt‑hole damage."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: addressing a specific mechanical defect in a specific propeller model series. It has not expanded beyond its original safety purpose of preventing counterweight separation due to bolt hole thread damage."},"complexity_factors":["Single, clearly defined applicability (specific propeller model and serial number range)","Only 2 compliance pathways based on hours since overhaul (simple binary condition)","Single requirement: one-time inspection plus reference to external technical document (Hartzell ASB)","No nested exceptions or conditional sub-clauses","Short document (under 300 words)","Only one defined term used ('TIS' — Time in Service, explained in context)","No cross-references to other legislation or regulations beyond the enabling authority (Civil Aviation Regulations 1998, Part 39)"],"plain_english_summary":"This CASA Airworthiness Directive mandates a one-time inspection of the counterweight clamp bolt hole for thread damage on specific Hartzell propellers (HC‑E4A‑3, S/N HJ1–HJ1040). It targets operators and maintainers—particularly if the propeller was overhauled or the clamp bolt removed—because damaged threads have allowed counterweights to detach in flight.\n\nInspections and any repairs must follow Hartzell ASB HC‑ASB‑61‑237 (Jul 1998). Compliance deadlines vary by hours‑in‑service (high‑use vs. others)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-72-counterweight-clamp-bolt-hole","history":"/api/acts/ad-phzl-72-counterweight-clamp-bolt-hole/history","analysis":"/api/acts/ad-phzl-72-counterweight-clamp-bolt-hole/analysis","conflicts":"/api/acts/ad-phzl-72-counterweight-clamp-bolt-hole/conflicts","importantCases":"/api/acts/ad-phzl-72-counterweight-clamp-bolt-hole/important-cases","documents":"/api/acts/ad-phzl-72-counterweight-clamp-bolt-hole/documents"}}