{"id":"F2006B06225","name":"AD/PHZL/67 - Propeller Blade Cracking","slug":"ad-phzl-67-propeller-blade-cracking","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47144,"registerId":"commonwealth-F2006B06225-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/67 - Propeller Blade Cracking","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/67 Propeller Blade Cracking 11/96 DM\n\nApplicability: All Hartzell HC-B3TN, HC-B5MP, HC-E4A and HC-D4N series propellers equipped with propeller blades identified by serial number and listed in the Requirement Document and were manufactured between March 1992 and June 1996. These propellers are installed on but not limited to the following aircraft;\n\nAir Tractor AT-502, AT-503 and AT-802 series Antonov AN-28 series\n\nAyres S2R series\n\nDouglas DC-3 (STC modified)\n\nAerospatiale (Nord) 262 (Mohawk) series (STC Modified) Norman Aeroplanes NAC-6 series\n\nPilatus PC-7 mk II, PC-9 and PC 12 series PZL PZL-M18 (STC Modified)\n\nShorts Brothers plc S-312 Tucano (Military), SD3 and C-23 (Military) series Twin Commander 690 and 695 series (STC Modified)\n\nRequirement: To prevent propeller blade separation caused by propeller blade shank cracks emanating from forging flaws, action in accordance with Hartzell Alert Service Bulletin HC-ASB-61-220 dated July 8/96.\n\nNote: FAA AD 96-15-04 Amdt 39-9697 refers.\n\nCompliance: 1. For propellers installed on agricultural or acrobatic aircraft such as Air Tractor\n\nAT-502, AT-503 and AT-802 series, Ayres S2R series, Norman Aeroplanes NAC- 6 series, Pilatus PC-7 mk II or PC-9 series, PZL PZL-M18 and Shorts Brothers plc S-312 Tucano (Military); unless previously carried out, within 10 hours time in service from an effective date of 23 August 1996.\n\n    2. For all other propellers regardless of aircraft installation; unless previously carried out, comply within 60 hours time in service from an effective date of 23 August 1996.\n\n    3. For propellers that have not complied with the requirements of this Directive, which experience a sudden or unusual vibration; prior to further flight effective from 23 August 1996.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nBackground: A Shorts Tucano propeller suffered an in-flight blade failure approximately 150 mm (6 inches) from the blade butt. Subsequent investigation of the blade stub confirmed a forging flaw was responsible for the blade failure. As it is unknown whether other blades manufactured from the same blade lot may be affected, all blades will require inspection.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific manufacturing defect in a defined batch of propellers. The scope remains tightly focused on the original safety issue identified — the forging flaw causing blade cracking — with no evidence of scope creep or expansion beyond the initial safety imperative."},"complexity_factors":["Multiple applicability criteria requiring cross-referencing with an external Requirement Document for serial numbers","Tiered compliance deadlines based on aircraft operational category (agricultural/acrobatic vs. other)","Conditional compliance trigger for sudden vibration (immediate grounding requirement)","Reference to external technical document (Hartzell Alert Service Bulletin) for actual inspection procedures","Cross-reference to corresponding FAA Airworthiness Directive (96-15-04) for additional context"],"plain_english_summary":"This CASA Airworthiness Directive mandates urgent inspections of certain Hartzell propeller blades (manufactured Mar 1992–Jun 1996) for forging‑flaw cracks that can cause in‑flight blade failure. It affects operators of aircraft fitted with those props (crop‑sprayers, military trainers, etc.), requires inspections per Hartzell HC‑ASB‑61‑220 within 10 hours for high‑stress use or 60 hours for others, and grounds aircraft immediately if unusual vibration occurs."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This directive stays within the original technical purpose: identify and remediate propeller blades from a specific manufacture period/lot suspected of a forging flaw to prevent shank cracking and blade separation. It does not materially broaden scope beyond addressing those blades and the installations listed; it cross‑references the manufacturer service bulletin for the precise inspection and corrective actions rather than adding new substantive obligations."},"complexity_factors":["Applicability depends on blade serial numbers listed in an external Requirement Document (cross‑reference required)","Manufacture date range condition (March 1992 to June 1996) in addition to serial numbers","Multiple propeller series covered (HC‑B3TN, HC‑B5MP, HC‑E4A, HC‑D4N) and a long list of aircraft types, including STC‑modified installations","Three different compliance timing conditions (10 hours for specified aircraft groups, 60 hours for others, immediate inspection after sudden/unusual vibration)","Cross‑references to Hartzell Alert Service Bulletin HC‑ASB‑61‑220 for inspection/repair procedure and to FAA AD 96‑15‑04","Operational consequences (grounding before further flight in certain circumstances) tied to inspection outcomes"],"plain_english_summary":"**What this instrument does**\n\n- This is an airworthiness directive requiring inspection and any follow-up action on certain Hartzell variable‑pitch propeller blades because some blades made in a specific period may have a forging flaw that can lead to cracking and blade separation.\n\n- The directive applies to Hartzell HC‑B3TN, HC‑B5MP, HC‑E4A and HC‑D4N series propellers that have blade serial numbers listed in the Requirement Document and that were manufactured between March 1992 and June 1996. Those propellers are fitted to — but not limited to — a list of aircraft types (for example, Air Tractor AT‑502/503/802, Shorts Tucano, Pilatus PC‑7 mk II/PC‑9/PC‑12, Antonov AN‑28, Douglas DC‑3 where modified, and others, including some STC‑modified installations).\n\n- It requires operators to carry out the inspection procedure set out in Hartzell Alert Service Bulletin HC‑ASB‑61‑220 (dated 8 July 1996) to detect shank cracks originating from forging flaws. The directive cross‑references FAA AD 96‑15‑04.\n\n**When the inspections must be done**\n\n- For propellers on agricultural or acrobatic aircraft listed (Air Tractor AT‑502/503/802, Ayres S2R, Norman NAC‑6, Pilatus PC‑7 mk II/PC‑9, PZL M‑18, Shorts Tucano): within 10 hours time‑in‑service from the effective date (23 August 1996), unless already done.\n\n- For all other affected propellers: within 60 hours time‑in‑service from the effective date, unless already done.\n\n- If an affected propeller that has not been inspected experiences a sudden or unusual vibration: it must be inspected before further flight.\n\n**Why it matters (stated purpose and practical effect)**\n\n- Purpose claimed by the directive: to prevent propeller blade separation caused by shank cracks that originate from forging flaws. A blade failure in a Shorts Tucano (blade fractured about 150 mm from the butt) prompted the inspections.\n\n- Who pays: aircraft owners/operators and their maintenance organisations bear the direct costs of inspections, any removals, repairs or blade replacements, and potential aircraft downtime.\n\n- Who decides: the Civil Aviation Safety Authority (by issuing the directive) mandates compliance; the technical method to inspect is prescribed by Hartzell's Alert Service Bulletin; maintenance organisations and certificated mechanics perform the inspections and corrective work.\n\n- Behaviour change required: operators must inspect identified blades within tight timeframes, ground aircraft for inspection after unusual vibration, and follow Hartzell's prescribed inspection/repair procedures. This reduces operational flexibility for affected operators until compliance is achieved.\n\n**Implementation, costs and trade‑offs**\n\n- Compliance burden is procedural: find serial numbers, schedule and perform inspections, and carry out any repair or replacement actions specified by the service bulletin. The short compliance windows (10 or 60 flight hours) create urgency and can cause near‑term grounding and scheduling disruption, especially for high‑utilisation operators.\n\n- Resource risks: availability of qualified maintenance personnel, inspection equipment and replacement blades may limit how quickly operators can comply and increase short‑term costs. If replacements are required, there will be material and labour expense.\n\n- Concentration of benefits and diffusion of costs: the safety benefit (reduced risk of catastrophic blade separation) is concentrated in avoided accidents, while costs are concentrated on the relatively smaller set of operators using the affected blades. There is no indication here of alternative mitigation options; the directive prescribes the inspection method developed by the manufacturer.\n\n- Regulatory and commercial interactions: the directive cross‑references the manufacturer service bulletin and an FAA AD, so operators must follow a combination of regulator mandate and manufacturer technical procedure. That reduces discretion for operators about inspection technique but aligns regulatory and manufacturer requirements.\n\n**Mechanics to watch for in practice**\n\n- Operators need to check the Requirement Document (where affected serial numbers are listed) to determine if their blades are in scope.\n\n- Short inspection deadlines may create immediate operational costs and opportunity costs (missed flights, rescheduling). If inspections find cracks, repair or replacement will increase direct costs and downtime.\n\n- The directive does not itself describe the inspection technique in full; it mandates compliance with the Hartzell Alert Service Bulletin, so the service bulletin’s detail determines the technical work and parts required.\n\n(Reference: AD/PHZL/67 Propeller Blade Cracking; Hartzell Alert Service Bulletin HC‑ASB‑61‑220; FAA AD 96‑15‑04.)"},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-67-propeller-blade-cracking","history":"/api/acts/ad-phzl-67-propeller-blade-cracking/history","analysis":"/api/acts/ad-phzl-67-propeller-blade-cracking/analysis","conflicts":"/api/acts/ad-phzl-67-propeller-blade-cracking/conflicts","importantCases":"/api/acts/ad-phzl-67-propeller-blade-cracking/important-cases","documents":"/api/acts/ad-phzl-67-propeller-blade-cracking/documents"}}