{"id":"F2006B06298","name":"AD/PMC/43 - Blade Shank Corrosion","slug":"ad-pmc-43-blade-shank-corrosion","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47391,"registerId":"commonwealth-F2006B06298-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PMC/43 - Blade Shank Corrosion","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 \\- McCauley\n\nAD/PMC/43 Blade Shank Corrosion 8/89\n\nApplicability: All McCauley Hubs P/No 41D5926 with blade P/No SS-135-6 or Hub P/No D-1093 with blade P/No SS-135-6M or SS-138-6.\n\nRequirement: Disassemble and inspect the hub and blade shank for fatigue cracks using an approved magnetic particle inspection technique.\n\nNote 1. The technique detailed in CAO 108-8 is an approved technique. Note 2. FAA AD 54-12-02 refers.\n\nCompliance: Unless already accomplished; by 31 August 1989. Thereafter reinspect at intervals not exceeding 100 hours time in service.\n\nBackground: To ensure fatigue cracking is detected before loss of a blade occurs, a recurring magnetic particle inspection is required. Affected propellers are fitted to Boeing Stearman aircraft and may be fitted to other older style aircraft.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive with a narrow, well-defined scope targeting specific propeller models for corrosion inspection. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear applicability criteria","Only 2 defined part number combinations to identify affected equipment","Straightforward compliance timeline (one fixed date + recurring interval)","No nested exceptions, conditional logic, or cross-references to other legislation sections","Minimal length (approximately 150 words)","Only references external standards (CAO 108-8, FAA AD 54-12-02) as helpful notes rather than binding conditions"],"plain_english_summary":"This is a **safety directive** issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific aircraft propellers to be inspected for dangerous corrosion and cracking.\n\n**What it does:**\n- Orders owners and operators of certain McCauley variable-pitch propellers to take them apart and check for **fatigue cracks** (tiny cracks that grow with repeated stress and can cause metal to break) in the hub and blade shank areas.\n- Mandates using **magnetic particle inspection** (a specialised technique using magnetic fields and iron particles to reveal hidden cracks in metal parts).\n\n**Who it affects:**\n- Owners and operators of aircraft fitted with specific McCauley propeller models:\n  - Hub part number 41D5926 with blade SS-135-6, OR\n  - Hub part number D-1093 with blades SS-135-6M or SS-138-6\n- These propellers are commonly found on **Boeing Stearman** aircraft and similar older-style planes.\n\n**What must be done:**\n- **Initial inspection:** Complete by 31 August 1989 (if not already done)\n- **Ongoing inspections:** Every 100 hours of flight time thereafter\n\n**Why it matters:**\nFatigue cracks in propeller blades can lead to **blade failure during flight** — a catastrophic safety risk. This directive ensures cracks are found before they cause a blade to break off."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's stated purpose is to detect fatigue cracking before blade loss and it prescribes inspections of specifically identified hub/blade part numbers to achieve that goal (Background; Applicability; Requirement). The directive does not expand the scope beyond those identified parts or beyond requiring recurring inspections at a specified interval; therefore the operational scope as set out in the instrument aligns with the stated intent and is not changed."},"complexity_factors":["Narrow technical applicability specified by exact part numbers (Applicability).","Single, well-defined required action: disassemble and magnetic-particle inspect blade shank for fatigue cracks (Requirement).","Mandatory use of an approved inspection technique (CAO 108-8 referenced) which imposes a method constraint (Note 1).","Fixed compliance timeline and recurring inspection interval (initial by 31 August 1989; thereafter ≤100 hours TIS) (Compliance).","Cross-reference to external documents (CAO 108-8 and FAA AD) that may require consult of other materials (Note 1, Note 2)."],"plain_english_summary":"This directive requires owners, operators and maintainers of aircraft fitted with specified McCauley propeller hubs and blades to disassemble the hub and perform an approved magnetic-particle inspection (CAO 108-8 referenced) of blade shanks to detect fatigue cracks. Initial inspections were due by 31 Aug 1989 (if not already done) and must be repeated at intervals no greater than 100 hours TIS. It imposes inspection costs, downtime and the need for qualified providers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pmc-43-blade-shank-corrosion","history":"/api/acts/ad-pmc-43-blade-shank-corrosion/history","analysis":"/api/acts/ad-pmc-43-blade-shank-corrosion/analysis","conflicts":"/api/acts/ad-pmc-43-blade-shank-corrosion/conflicts","importantCases":"/api/acts/ad-pmc-43-blade-shank-corrosion/important-cases","documents":"/api/acts/ad-pmc-43-blade-shank-corrosion/documents"}}