{"id":"F2006B06220","name":"AD/PHZL/60 Amdt 4 - Three Bladed Y Shank Aluminium Hubs","slug":"ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47129,"registerId":"commonwealth-F2006B06220-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Agricultural Aircraft","sectionType":"part","heading":"Agricultural Aircraft","content":"# Agricultural Aircraft\n\nFletcher FU24-950\n\nCessna A188 Agwagon modified by STC SA895SO\n\nPiper PA-36-285 and PA-36-300 (three bladed propellers only) PA-36-375","sortOrder":0},{"sectionNumber":"Aircraft with Textron Lycoming (L)TIO-54","sectionType":"part","heading":"Aircraft with Textron Lycoming (L)TIO-540 and Turbocharged IO-540 series engines","content":"# Aircraft with Textron Lycoming (L)TIO-540 and Turbocharged IO-540 series engines\n\nCessna 310 and 320 modified by Riley STC SA2082WE Gulfstream 700 (formerly Rockwell 700, Fuji FA-300-12) Helio H-700\n\nPiper PA-23-250, PA-E23-250 (with TIO-540 only)\n\nPiper PA-31 Navajo (with TIO-540 only)\n\nPiper PA-31-325 Navajo C/R\n\nPiper PA-31-350 Navajo “Chieftain” Piper PA-31P-350 Mohave\n\nPiper T-1020 (same as PA-31-350) Piper A-32(R)-301T Turbo Saratoga\n\nAerostar PA-60-600, PA-60-601, PA-60-601P PA-60-602P, and PA-60-700P\n\nRequirement: 1. Carry out a visual inspection of the hub using a 10X glass looking for signs of cracking or grease leakage. Replace any hub found cracked prior to further flight. Perform an eddy current or dye penetrant inspection in accordance with the procedures specified in Hartzell SB 165E on any of the above specified model and S/N propellers installed on any agricultural aircraft or Piper PA-31-325 Navajo C/R, Piper PA-31-350 Navajo “Chieftain”, Piper T-1020 (same as PA-31-350), PA-60-700P or Aerostar 700P aircraft.\n\n    2. For all other aircraft types listed in this Directive carry out a visual inspection of the hub using a 10X glass looking for signs of cracking or grease leakage. Replace any hub found cracked prior to further flight. Perform an eddy current or dye penetrant inspection IAW the procedures specified in Hartzell SB 165E.\n\n    3. For propellers installed on agricultural aircraft or Piper PA-31-325 Navajo C/R, Piper PA-31-350 Navajo “Chieftain”, Piper T-1020 (same as PA-31-350), PA-60- 700P or Aerostar 700P aircraft, replace pre 1983 style hubs with post 1983 hubs. If during overhaul, post 1983 style hubs are not available and the hub passes overhaul requirements then, the pre 1983 hub chamfer modification in accordance with Procedure 2 of Hartzell SB 165E may be incorporated. Hubs so modified are exempt from Requirements 1 and 2 of this Directive.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This amendment expands and sharpens mandatory actions compared with a simple inspection directive. It does three things beyond a basic inspection requirement: (a) mandates replacement of pre‑1983 hubs with post‑1983 hubs for a defined subset of aircraft, (b) prescribes a specific alternative modification (Procedure 2 of Hartzell SB 165E) as an exemption to routine inspection requirements when post‑1983 hubs are unavailable, and (c) explicitly applies eddy‑current/dye‑penetrant NDT to the listed propellers. Those elements extend the instrument from a passive inspection requirement to a prescriptive parts‑replacement and conditional‑modification regime, increasing the scope of obligations on operators and maintenance providers."},"complexity_factors":["Multiple lists of affected aircraft types (agricultural subset plus a larger Lycoming IO‑540 family list) creating conditional applicability","Three distinct requirements with overlapping but different applicability (Req 1 for agricultural + certain Pipers/Aerostar; Req 2 for other listed types; Req 3 limited to some types)","Cross‑reference to an external technical document (Hartzell Service Bulletin 165E) for inspection and modification procedures","A date‑cutoff distinction (pre‑1983 vs post‑1983 hubs) requiring parts history tracking","Conditional exemption path (chamfer modification at overhaul) that creates an exception to the inspection requirements","Technical testing modalities mandated (eddy current or dye penetrant) that require specialised equipment and trained personnel","References to STC‑modified aircraft and serial‑number‑specific propellers in at least one paragraph, adding traceability burden","No in‑instrument definitions of key terms such as “agricultural aircraft” or explicit timeframes for when inspections must be done, increasing interpretive complexity"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- It requires operators and maintenance organisations to inspect and, where necessary, replace or modify certain three‑bladed aluminium hubs on Hartzell Y‑shank propellers installed on a specific list of aircraft models.\n- Requirement 1 (for agricultural aircraft and a short list of Piper/Aerostar types):\n  - Do a visual inspection of the hub with a 10× magnifying glass for cracking or grease leakage. If cracked, replace the hub before next flight.\n  - Perform a non‑destructive test (eddy current or dye‑penetrant) following Hartzell Service Bulletin 165E.\n- Requirement 2 (for the other listed aircraft types):\n  - Same 10× visual inspection and replacement if cracked, and perform eddy current or dye‑penetrant inspection per Hartzell SB 165E.\n- Requirement 3 (for agricultural aircraft and the same limited Piper/Aerostar subset):\n  - Replace any hubs made before 1983 with post‑1983 style hubs.\n  - If a post‑1983 hub is not available at overhaul and the pre‑1983 hub meets overhaul criteria, the pre‑1983 hub may be modified (a chamfer modification per Procedure 2 of Hartzell SB 165E). Hubs modified this way are exempt from Requirements 1 and 2.\n\nAffected aircraft (by example, not exhaustive): Fletcher FU24‑950; Cessna A188 Agwagon with STC SA895SO; several Piper PA‑36 series (three‑blade props only); a list of aircraft with Lycoming (L)TIO‑540 and turbocharged IO‑540 series engines including some Cessna 310/320 STC modifications, Gulfstream 700 (FA‑300‑12), Helio H‑700, multiple Piper PA‑23/PA‑31 variants, Aerostar PA‑60 series, and others. The instrument expressly links certain requirements to the “agricultural aircraft” category and named Piper/Aerostar types.\n\n**Who this affects**\n\n- Aircraft owners/operators and maintenance organisations that operate the listed aircraft with the specified Hartzell three‑bladed Y‑shank aluminium hubs.\n- Maintenance technicians and facilities that perform eddy current or dye‑penetrant inspections (these require trained personnel and equipment).\n- Parts suppliers and overhaul shops because replacement post‑1983 hubs are mandated for certain aircraft or specific chamfer modification must be available.\n\n**Why it matters (stated purpose and practical effect)**\n\n- The instrument cites inspection and replacement to detect and remove hubs with cracking or grease leakage and to impose a design‑age upgrade (post‑1983 hubs) or an approved modification where that upgrade is not available. The stated purpose (safety) is to prevent hub failure that could lead to propeller separation or loss of control.\n\n**Costs, incentives and implementation effects**\n\n- Direct costs fall on operators: labour for inspections, NDT costs (eddy current/dye‑penetrant), and parts costs for replacement hubs. Overhaul shops also bear the cost of carrying out tests and any chamfer modification.\n- Availability risk: if post‑1983 hubs are in short supply, operators may face grounding delays or accept the chamfer modification route subject to overhaul acceptance, which may shift costs toward skilled overhaul services.\n- Compliance burden: NDT requires specialised equipment and trained technicians. Smaller operators or remote agricultural operators may need to travel or contract specialised shops.\n- Behavioural effect: operators will increase inspection frequency and replace or modify older hubs; some may retire or restrict use of affected propellers until compliance is achieved.\n- Market impact: increased demand for post‑1983 hubs or skilled overhaul services may raise prices or create supply bottlenecks; conversely, exemption by modification can reduce pressure on scarce parts.\n\n**Tradeoffs and risks**\n\n- Safety benefit (removal of cracked hubs / improved hub design) versus direct monetary and operational costs for inspection and replacement.\n- Reliance on Hartzell SB 165E centralises the compliance method: it provides a single technical standard (clarifies how to test/modify), but also concentrates dependence on the manufacturer’s procedures.\n- The chamfer modification creates a conditional compliance path that reduces the immediate need to stock post‑1983 hubs, but it places judgement on overhaul acceptance and may shift risk to maintenance organisations.\n\n**Who pays, who decides, and what changes in behaviour**\n\n- Who pays: aircraft owners/operators and authorised maintenance organisations pay for inspections, NDT, parts and modifications.\n- Who decides: approved maintenance organisations and certificated inspectors decide whether a hub passes inspection or must be replaced, and whether the chamfer modification is appropriate when post‑1983 hubs are unavailable.\n- Behaviour change: more frequent inspection and testing, replacement of pre‑1983 hubs on named types, possible grounding or limited operational availability until compliance is achieved.\n\n**Where the requirements appear (mechanical citation)**\n\n- Visual inspection + 10× glass + replace if cracked: Requirement 1 & Requirement 2.\n- Eddy current or dye‑penetrant testing IAW Hartzell SB 165E: Requirement 1 & 2.\n- Replace pre‑1983 hubs with post‑1983 hubs for specified types; allow chamfer modification per Procedure 2 SB 165E as temporary/alternative compliance and exempt modified hubs from Requirements 1 & 2: Requirement 3."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This appears to be a focused safety directive targeting a specific mechanical defect in a defined set of aircraft propeller hubs. The scope remains tightly constrained to the original safety issue (Y-shaped aluminium hub cracking) and has not expanded beyond this technical airworthiness matter."},"complexity_factors":["Multiple aircraft type categories with different compliance requirements (agricultural vs. non-agricultural)","Nested conditional logic: different inspection requirements based on aircraft type, with further exceptions for overhaul scenarios","Cross-reference to external technical document (Hartzell SB 165E) without reproducing its contents","Specific serial number and model year distinctions (pre-1983 vs. post-1983 hubs)","Exemption clause that modifies earlier requirements based on modification compliance","Inconsistent formatting and apparent copy-paste errors in the source text (duplicate headings, fragmented lines)"],"plain_english_summary":"This mandatory Airworthiness Directive orders owners/operators of certain three‑bladed Y‑shaped aluminium propeller hubs to inspect for cracks or grease leaks and to replace any cracked hubs before flight, using eddy‑current or dye‑penetrant inspections per Hartzell Service Bulletin 165E. It targets agricultural aircraft (crop‑sprayers) and specific twin‑engine types fitted with these hubs. It matters because fatigue cracks can cause catastrophic hub failure, so the rule prevents in‑flight loss of control by catching and replacing compromised hubs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs","history":"/api/acts/ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs/history","analysis":"/api/acts/ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs/analysis","conflicts":"/api/acts/ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs/conflicts","importantCases":"/api/acts/ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs/important-cases","documents":"/api/acts/ad-phzl-60-amdt-4-three-bladed-y-shank-aluminium-hubs/documents"}}