{"id":"F2006B04891","name":"AD/CERES/2 Amdt 1 - Propeller Counterweights - Modification","slug":"ad-ceres-2-amdt-1-propeller-counterweights-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44698,"registerId":"commonwealth-F2006B04891-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CERES/2 Amdt 1 - Propeller Counterweights - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 9/1999,Aircraft below 5700 kg,C.A.C. CA-28 (Ceres) Series Aeroplanes,Propeller Counterweights - Modification,2 Amdt 1\ntitle: Airworthiness Directive - AD/CERES/2 Amdt 1 - Propeller Counterweights - Modification\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  C.A.C. CA-28 (Ceres) Series Aeroplanes\n\n \n\nAD/CERES/2\n\nAmdt 1\n\n\nPropeller Counterweights - Modification 9/99\n\n \n\nApplicability: All models fitted with high solidity propeller P/N 284402. Document:  Ceres SB No. 33.\n\nCompliance: Before Propeller Installation.\n\n \n\nNote: Modifications performed in accordance with AD/CA-28/2 satisfy the requirements of this Directive.\n\n \n\nThis Amendment becomes effective on 9 September 1999.\n\n \n\nBackground The original issue of this Airworthiness Directive became effective in Issue AL 8/62.\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\nFederal Register of Legislative Instruments F2006B04891\n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1563},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Amendment 1 (1999) maintains the original scope established in 1962 (Issue AL 8/62). It continues to address the same specific propeller counterweight modification requirement for the same aircraft type without expanding applicability or adding new substantive requirements beyond the original safety intent."},"complexity_factors":["Extremely brief document (less than 200 words)","Single applicability criterion based on specific propeller part number","One-sentence compliance requirement with no conditional exceptions","No defined terms or interpretation section","Single alternative compliance pathway referenced (AD/CA-28/2)"],"plain_english_summary":"**What this is:** A mandatory safety instruction (called an *Airworthiness Directive*) issued by the aviation regulator requiring a specific mechanical fix on vintage aircraft propellers.\n\n**Who it affects:** Owners and operators of **C.A.C. CA-28 (Ceres)** series aeroplanes—agricultural aircraft built in Australia during the 1950s and 1960s—**but only if** fitted with a specific type of propeller (high solidity propeller part number 284402).\n\n**What you must do:** Before installing one of these propellers on the aircraft, you must modify the propeller counterweights (balancing weights) according to the manufacturer's Service Bulletin No. 33. \n\n**Alternative compliance:** If you've already carried out modifications under a previous directive (AD/CA-28/2), that satisfies this requirement—you don't need to do it again.\n\n**Why it matters:** Propeller counterweights are critical for safe operation. This rule prevents unsafe propeller installations that could lead to mechanical failure in flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ceres-2-amdt-1-propeller-counterweights-modification","history":"/api/acts/ad-ceres-2-amdt-1-propeller-counterweights-modification/history","analysis":"/api/acts/ad-ceres-2-amdt-1-propeller-counterweights-modification/analysis","conflicts":"/api/acts/ad-ceres-2-amdt-1-propeller-counterweights-modification/conflicts","importantCases":"/api/acts/ad-ceres-2-amdt-1-propeller-counterweights-modification/important-cases","documents":"/api/acts/ad-ceres-2-amdt-1-propeller-counterweights-modification/documents"}}