{"id":"F2006B11445","name":"AD/P166/19 - Carburettor Air Mixer Valve - Inspection and Modification","slug":"ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57387,"registerId":"commonwealth-F2006B11445-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/P166/19 - Carburettor Air Mixer Valve - Inspection and 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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Piaggio P166 Series Aeroplanes\n\n \n\nAD/P166/19 Carburettor Air Mixer Valve - Inspection\n\nand Modification\n\n\n7/62\n\n \n\nApplicability: Aeroplanes equipped with carburettor air mixer valve having a cylinder shaped valve body.\n\n \n\nDocument: Piaggio SB P166-19. Compliance: Modification - Forthwith.\n\nInspection - At intervals not exceeding 200 hours time in service.\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 standard, narrow Airworthiness Directive targeting a specific mechanical component on a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section — uses plain technical language","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple binary applicability test (cylinder-shaped valve body = yes/no)","Straightforward compliance requirements with clear timeframes","Single source document referenced (Piaggio SB P166-19)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for specific Piaggio P166 series aircraft.\n\n**What it does:**\n- Requires owners/operators of affected aeroplanes to **inspect and modify** a specific part called the \"carburettor air mixer valve\" (a component that mixes air and fuel in the engine's carburettor system).\n- The valve in question has a distinctive **cylinder-shaped body**.\n\n**Who it affects:**\n- Anyone operating Piaggio P166 series aircraft that have this specific type of carburettor air mixer valve installed.\n\n**What must be done:**\n- **Modification:** Must be carried out **immediately** (\"forthwith\" means without delay).\n- **Inspection:** Must be repeated **every 200 hours** of flight time (\"time in service\" means actual operating hours, not calendar time).\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. Non-compliance can ground an aircraft or result in penalties. This particular AD addresses a potential safety issue with the carburettor air mixer valve that could affect engine performance or safety.\n\n**Source document:** The technical details are found in Piaggio Service Bulletin P166-19."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"There is no information in the provided text indicating that the scope of the directive has changed from an earlier instrument or from the original intent. The AD explicitly applies to Piaggio P166 series aeroplanes with the specified cylinder-shaped carburettor air mixer valve and mandates an immediate modification plus inspections every 200 hours, consistent with a single, focused airworthiness directive. Any change-of-scope evidence would need to appear in preceding or amending documents, which are not present in the supplied text."},"complexity_factors":["Narrow applicability limited to Piaggio P166 series aeroplanes with a cylinder-shaped carburettor air mixer valve (Applicability).","Two clear mandatory actions with simple timing: an immediate modification (forthwith) and recurring inspections at intervals not exceeding 200 hours TIS (Compliance).","Reliance on an external technical document (Piaggio SB P166-19) for procedural detail creates a single dependency but does not add statutory complexity (Document).","Implementation uncertainty from absence of technical detail and parts/labour estimates in the AD text (Document), which can complicate practical scheduling and cost estimation.","Regulatory enforcement is direct and prescriptive, leaving limited discretionary interpretation for operators beyond scheduling within the stated timing."],"plain_english_summary":"If you operate a Piaggio P166 fitted with the cylindrical carburettor air‑mixer valve, this AD requires you to have that valve modified forthwith and then inspected at intervals not exceeding 200 hours TIS, following Piaggio Service Bulletin P166‑19. Owners/operators bear the costs and downtime; maintenance organisations must perform the work per the SB. The measure addresses a valve condition the regulator deems a safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification","history":"/api/acts/ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification/history","analysis":"/api/acts/ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification/analysis","conflicts":"/api/acts/ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification/important-cases","documents":"/api/acts/ad-p166-19-carburettor-air-mixer-valve-inspection-and-modification/documents"}}