{"id":"F2012L00560","name":"AD/PHZL/74 Amdt 2 - Two Blade 'Y\" Shank Aluminium Hub","slug":"ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":88766,"registerId":"commonwealth-F2012L00560-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Propellers - Variable Pitch - Hartzell","sectionType":"division","heading":"Propellers - Variable Pitch - Hartzell","content":"### Propellers - Variable Pitch - Hartzell\n\n| AD/PHZL/74 Amdt 2 | Two Blade ‘Y” Shank Aluminium Hub | 6/2012 |\n| ----------------- | --------------------------------- | ------ |\n\n```html\n

Applicability:

1. () HC- () 2Y()- () propellers (also known as Y-shank propellers) that have a hub serial number with “A”, “E”, or no suffix, and installed on or previously installed on:

a. Piper PA-32 series aircraft with Textron Lycoming 540 series engines that are rated at 300HP or higher; or

b. Pilatus Britten Norman or Britten Norman BN-2 series aircraft (also known as Islander or Trislander) with Textron Lycoming 540 series engines; or

c. Any aircraft certified in the aerobatic category; or

d. Any aircraft routinely exposed to aerobatic manoeuvres; or

e. Any aircraft that has been used for agricultural operations whilst the applicable propeller was installed.

Note 1: This AD does not apply to propellers with the suffix letter “B” at the end of the hub serial number.

Note 2: Incorporation of a “B” suffix hub will provide terminating action for this Directive.

2. () HC- () 2Y()- () propellers S/N’s listed in Table 1:

Table 1. () HC- () 2Y()- () propellers with the following S/N’s

DN3607A

DN3609A

DN3613A

DN3615A

DN3628A

DN3630A

DN3641A

DN3940A

DN3944A

DN3949A

DN3962A

\n```\n\n| Requirement: | 1. Eddy Current Inspection:a. No Suffix: For propeller hubs without any serial number suffix carry out an Eddy Current Inspection (ECI) of the propeller hub fillet radius for cracks in accordance with Hartzell SB HC-SB-61-227 Revision 5 dated September 28, 2006 or later FAA approved revision.b. If no cracks are found then permanently mark the end of the hub serial number with the suffix “E” in accordance with Hartzell SB HC-SB-61-227 Revision 5 dated September 28, 2006 or later FAA approved revision.c. E Suffix: For propeller hubs with serial number suffix “E” carry out repetitive Eddy Current Inspections (ECI) of the propeller hub fillet radius for cracks in accordance with Hartzell SB HC-SB-61-227 Revision 5 dated September 28, 2006 or later FAA approved revision.d. Table 1: For propeller hubs with a serial number hub listed in Table 1 carry out initial and repetitive ECI as per Hartzell SB HC-SB-61-227 Revision 5 dated September 28, 2006 or later FAA approved revision.e. Propeller hubs that are cracked are to be replaced prior to further flight.2. Hub Replacement:a. A Suffix: “A” suffix hubs not listed by serial number in Table 1 shall be removed from service in accordance with Hartzell SB HC-SB-61-227 Revision 5 dated September 28, 2006 or later FAA approved revision.b. Table 1: All hubs listed by serial number in Table 1 shall be removed from service in accordance with Hartzell SB HC-SB-61-227 Revision 5 dated September 28, 2006 or later FAA approved revision.Propeller hubs removed from service as a result of this Directive shall have the hub serial number and type certificate number permanently removed.Previous credit is allowed for inspections, rework, and replacements that were done using the preceding revisions of Hartzell Propeller Inc. SB No. HC-SB-61-227, before the effective date of this AD. |\n| ------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Note 3: FAA AD 2001-23-08 Amdt 39-12505 refers.Later revisions to Hartzell Propeller Inc. SB No. HC-SB-61-227, Revision 2, dated May 8, 2000, approved by the United States Federal Aviation Administration (FAA) as an Alternative Method of Compliance (AMOC) to FAA 2001-23-08 Amdt39-12505, are considered acceptable for compliance with the equivalent Requirements of this AD. |\n\n| Compliance: | 1. Eddy Current Inspection:a. No Suffix: Unless previously carried out; within 50 propeller hours Time In Service (TIS) from the effective date of this Directive.b. E Suffix: At intervals not to exceed 100 propeller hours TIS from the last ECI.c. Table 1: Unless previously carried out within 50 propeller hours TIS, and thereafter at intervals not to exceed 100 hours from the last ECI. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | 2. Hub Replacement:a. A Suffix: Propellers with the suffix “A” at the end of the hub serial number excluding those S/N’s listed in Table 1 of applicability, are to be replaced as follows:i. PA-32 and BN-2 series aircraft; at next propeller overhaul but no later than 2000 hours propeller TIS or 31 December 2005, whichever comes first.ii. Aircraft certified in the aerobatic category or aircraft routinely exposed to aerobatic manoeuvres; at next propeller overhaul but not to exceed 1000 propeller hours TIS or 31 December 2005, whichever comes first. For propeller hubs exceeding 1000 hours time in service as of the original effective date of this Directive, remove from service within 15 propeller hours TIS.iii. Agricultural aircraft; at next propeller overhaul, but not to exceed 2000 hours propeller TIS or 31 December 2005, whichever comes first.b. Table 1: At next propeller overhaul but not to exceed 1000 hours propeller TIS or 31 December 2005, whichever comes first. For propeller hubs exceeding 1000 hours TIS as of the original effective date of this Directive, remove from service within 15 hours propeller TIS.Note 4: Installation of the “B” serial number suffix hub will require spinner bulkhead modification per Hartzell Manual 113B or Hartzell Manual 117D dependant on propeller type. |\n| | This Amendment becomes effective on 13 March 2012. |\n\n| Background: | There have been incidents of hub cracks in Hartzell two blade \"compact\" aluminum hub propellers. Existing methods using visual inspection has proven to be unsuccessful in detecting cracks. There have now been cases of blade separation. ECI is now considered the only reliable method for detecting cracks. Cracks typically initiate at the same point on the hub. The cracks originate in the hub at a point adjacent to the blade called the \"fillet radius\". As the cracks propagate toward the centre of the hub, their progression accelerates and results in failure of one hub half, which can then potentially, progress to blade separation.The original issue of this Airworthiness Directive became effective on 16 May 2002.Amendment 1 introduced a change to include aircraft that can be routinely exposed to aerobatic maneuvers. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Amendment 2 harmonizes the repetitive inspection interval with the latest revision of the manufacturers service bulletin which is approved as an AMOC with FAA AD 2001-23-08. |\n\n![](image.001.png)\n\nMike Higgins \nDelegate of the Civil Aviation Safety Authority\n\n9 March 2012","sortOrder":0},{"sectionNumber":"AD/PHZL/74 Amdt 2","sectionType":"part","heading":"AD/PHZL/74 Amdt 2","content":"## AD/PHZL/74 Amdt 2","sortOrder":1},{"sectionNumber":"Two Blade ‘Y” Shank Aluminium Hub","sectionType":"part","heading":"Two Blade ‘Y” Shank Aluminium Hub","content":"## Two Blade ‘Y” Shank Aluminium Hub","sortOrder":2},{"sectionNumber":"6/2012","sectionType":"part","heading":"6/2012","content":"## 6/2012","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Yes. The original AD (effective 16 May 2002) was modified by Amendment 1 to expand applicability to aircraft routinely exposed to aerobatic manoeuvres. Amendment 2 did not expand affected aircraft categories but harmonised the repetitive inspection interval with the latest Hartzell service bulletin and FAA AMOC; removal and replacement requirements remain tied to the listed S/Ns, suffixes and aircraft categories (Background; Amendment notes)."},"complexity_factors":["Technical inspection requirement: mandatory Eddy Current Inspection (ECI) of the hub fillet radius (Requirement 1; Compliance 1).","Multiple applicability criteria: serial‑number suffixes (no suffix, “E”, “A”, “B”) plus a specific Table 1 of serial numbers and several aircraft categories (Applicability para 1; Table 1).","Differentiated compliance timelines and removal deadlines by aircraft type (PA‑32/BN‑2, aerobatic, agricultural) and by hub listing in Table 1 (Compliance 2(a)(i–iii); 2(b)).","Terminating and remedial actions: marking hubs with suffix “E” after ECI, replacing cracked hubs before further flight, and ‘‘B’’ suffix installation as terminating action but requiring spinner bulkhead modification (Requirement 1a–e; Notes).","Interplay with external documents and approvals: references to Hartzell SB HC‑SB‑61‑227 (various revisions) and FAA AD/AMOC acceptances (Requirement notes; Background).","Historic amendments affecting scope and intervals (original AD, Amendment 1 and Amendment 2), creating legacy compliance credit rules (Background; Note 3).","Administrative details: permanent removal of hub serial/type certificate numbers when hubs are removed from service and allowance for prior‑done work using earlier SB revisions (Requirement 2; Previous credit)."],"plain_english_summary":"Requires Eddy Current Inspection (ECI) of the fillet radius and specified removal or replacement of certain Hartzell two‑blade Y‑shank aluminium propeller hubs. It applies to hubs identified by serial‑number suffix or listed serial numbers and to Piper PA‑32, BN‑2/Trislander, aerobatic (and routinely aerobatic‑exposed) and agricultural aircraft. Operators and owners pay for inspections, markings and any hub replacements; the regulator enforces the ECI requirement because visual checks failed to detect cracks that led to blade separation."},"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":6,"scope_assessment":{"changed":true,"description":"The original 2002 directive has expanded significantly through two amendments. Amendment 1 added aircraft 'routinely exposed to aerobatic manoeuvres' beyond just certified aerobatic aircraft. Amendment 2 harmonised inspection intervals with the manufacturer's latest service bulletin and FAA requirements, effectively outsourcing technical compliance standards to an external document (Hartzell SB HC-SB-61-227 Revision 5). The scope has shifted from a standalone Australian directive to one that tracks and incorporates US FAA alternative compliance methods."},"complexity_factors":["Multiple overlapping applicability categories (5 different aircraft/usage types plus specific serial numbers)","Different compliance requirements based on hub suffix status (no suffix, \"A\", \"E\", or \"B\")","Nested conditional logic: different inspection intervals and replacement deadlines depending on aircraft type, hub suffix, and whether hub appears in Table 1","Cross-references to external documents: Hartzell Service Bulletin HC-SB-61-227 Revision 5 and FAA AD 2001-23-08","Time-based compliance calculations using multiple variables (propeller hours TIS, calendar dates, overhaul schedules)","Technical terminology requiring aviation engineering knowledge (eddy current inspection, fillet radius, spinner bulkhead modification)","Amendment history tracking (original 2002 issue, Amendment 1 for aerobatic aircraft, Amendment 2 for harmonised intervals)"],"plain_english_summary":"This AD requires mandatory eddy‑current crack inspections and, where necessary, replacement of Hartzell two‑blade “Y‑shank” aluminium propeller hubs to prevent blade separation. It applies mainly to Piper PA‑32s with 300+ HP Lycomings, Britten Norman Islander/Trislander types, aerobatic and agricultural operations, and to hubs with serial suffixes “A”, “E” or no suffix (plus listed serial numbers); “B”‑suffix hubs are terminating action. Hubs that pass must be permanently marked; affected “A”‑suffix hubs face replacement deadlines."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub","history":"/api/acts/ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub/history","analysis":"/api/acts/ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub/analysis","conflicts":"/api/acts/ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub/conflicts","importantCases":"/api/acts/ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub/important-cases","documents":"/api/acts/ad-phzl-74-amdt-2-two-blade-y-shank-aluminium-hub/documents"}}