{"id":"F2006B06281","name":"AD/PMC/22 - Counterweight Attachment - Modification","slug":"ad-pmc-22-counterweight-attachment-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47335,"registerId":"commonwealth-F2006B06281-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PMC/22 - Counterweight Attachment - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Propellers - Variable Pitch - McCauley\n\n \n\nAD/PMC/22 Counterweight Attachment - Modification 10/71\n\nApplicability: Models 2AF36C39, D2AF36C48, D2AF34C52, 2AF34C55 and 2AF36C89.\n\n \n\nDocument: 1. McCauley SB No. 93 and Revisions 93-1 and 93-2; or\n\n \n\n2. FAA AD 71-18-2.\n\n \n\nCompliance: Before installation on an aircraft following next reconditioning completed after 31 December 1971.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused specifically on counterweight attachment modifications for five McCauley propeller models. It has not expanded beyond its original technical scope."},"complexity_factors":["Very short document (approximately 150 words)","Only 5 specific propeller models listed in applicability","Single compliance requirement with clear deadline (post-31 December 1971 reconditioning)","Two alternative reference documents provided for compliance (McCauley SB or FAA AD)","No defined terms section","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","No conditional logic or nested exceptions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires a specific modification to certain McCauley propeller models to fix a problem with how counterweights are attached.\n\n**What it does:**\n- Mandates a design change to the counterweight attachment on five specific McCauley variable-pitch propeller models\n- Requires compliance before these propellers can be installed on aircraft after their next reconditioning (overhaul) completed after 31 December 1971\n\n**Who it affects:**\n- Owners and operators of aircraft with McCauley propellers models: 2AF36C39, D2AF36C48, D2AF34C52, 2AF34C55, and 2AF36C89\n- Aircraft maintenance organisations that recondition these propellers\n\n**Why it matters:**\nCounterweights on variable-pitch propellers are critical safety components that help control blade angle. A faulty attachment could lead to propeller failure, potentially causing loss of control or engine damage. This AD ensures the modification is applied to prevent accidents.\n\n**How to comply:**\nFollow either:\n- McCauley Service Bulletin No. 93 (including revisions 93-1 and 93-2), **or**\n- FAA Airworthiness Directive 71-18-2 (the US equivalent safety order)"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument's scope is defined in the text: it applies to the listed McCauley propeller models (Applicability), requires compliance using the two named documents (Document), and fixes the timing of compliance to the next reconditioning completed after 31 December 1971 (Compliance). Based on the supplied text alone, the scope as written is consistent with those stated elements and does not indicate a change from a different original scope within the instrument itself."},"complexity_factors":["Reference to external technical documents (McCauley SB No. 93 and revisions; FAA AD 71-18-2) creates dependency on those texts for full technical instructions (Document).","Conditional timing rule — compliance tied to 'next reconditioning completed after 31 December 1971' — requires implementers to track reconditioning dates and completion status (Compliance).","Applicability is limited to a specific list of propeller models, so implementers must determine whether a given unit is one of the listed models (Applicability).","The instrument is prescriptive but silent on alternative means of compliance or exemptions, which can create uncertainty for edge cases (Document; Compliance).","Technical work requires qualified maintenance capability, so practical compliance involves skilled labour, parts and workshop resources (implicit from requirement to follow service bulletin)."],"plain_english_summary":"Requires modification of the counterweight attachment on specified McCauley variable‑pitch propellers, to be carried out according to McCauley Service Bulletin No. 93 (and revisions) or FAA AD 71‑18‑2.  \n\nThe work is required at each propeller’s first reconditioning completed after 31 December 1971. It therefore affects aircraft owners/operators and overhaul organisations, who must perform and pay for the prescribed modification and follow the named technical documents; the instrument does not provide alternatives or funding."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pmc-22-counterweight-attachment-modification","history":"/api/acts/ad-pmc-22-counterweight-attachment-modification/history","analysis":"/api/acts/ad-pmc-22-counterweight-attachment-modification/analysis","conflicts":"/api/acts/ad-pmc-22-counterweight-attachment-modification/conflicts","importantCases":"/api/acts/ad-pmc-22-counterweight-attachment-modification/important-cases","documents":"/api/acts/ad-pmc-22-counterweight-attachment-modification/documents"}}