{"id":"F2006B11447","name":"AD/P166/20 - Hydraulic Pressure Gauges - Replacement","slug":"ad-p166-20-hydraulic-pressure-gauges-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57391,"registerId":"commonwealth-F2006B11447-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/P166/20 - Hydraulic Pressure Gauges - Replacement","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/P166/20 Hydraulic Pressure Gauges - Replacement 8/62\n\nApplicability: All model P166. Document:  Piaggio SB P166-27. Compliance:  Forthwith.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive. It has not expanded beyond its original purpose of addressing a specific airworthiness concern with hydraulic pressure gauges on P166 aircraft."},"complexity_factors":["Extremely short document — approximately 100 words of substantive content","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Simple, unqualified command: replace the gauges immediately","Single applicability criterion (all P166 models)","No exceptions, exemptions, or conditional logic"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires the **immediate replacement of hydraulic pressure gauges** on all Piaggio P166 series aeroplanes (a type of Italian-made twin-engine aircraft used in Australia).\n\n**Who it affects:** \n- **Owners and operators** of Piaggio P166 aircraft\n- **Maintenance engineers** who service these planes\n\n**Why it matters:** Hydraulic pressure gauges are critical safety instruments. They tell pilots if the aircraft's hydraulic systems (which control things like landing gear, brakes, and flight controls) are working properly. A faulty gauge could mean a pilot doesn't realise there's a problem until it's too late. This directive acts \"forthwith\" — meaning **do it immediately**, not at the next scheduled service.\n\n**The technical basis:** The directive references \"Piaggio SB P166-27\" — that's a Service Bulletin from the manufacturer (Piaggio) identifying a defect or unsafe condition with these gauges."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied text does not indicate any change in scope from an earlier instrument. It states applicability (all model P166), refers to a service bulletin for technical details, and requires immediate compliance. No information in the provided text suggests the AD widens or narrows scope relative to an earlier directive; therefore there is no basis in the supplied material to conclude the scope has changed."},"complexity_factors":["Universal applicability to the entire P166 fleet increases operational reach but simplifies eligibility determination (\"Applicability: All model P166.\").","Immediate compliance requirement increases operational urgency and scheduling complexity (\"Compliance: Forthwith.\").","Technical details are delegated to an external document (Piaggio SB P166-27), so implementers must obtain and interpret that bulletin to know exact parts and procedures (\"Document: Piaggio SB P166-27.\").","The AD text provided contains no stated technical rationale, failure data, or alternatives, which increases the need for implementers to rely on the service bulletin or regulator guidance (absence of explanatory material in the supplied text).","Enforceability is straightforward (issued under CASA's Schedule of Airworthiness Directives), but the AD provides no built-in exemptions or compliance sequencing, which leaves little formal discretion for operators within the text supplied."],"plain_english_summary":"What this directive does (mechanically)\n\n- The Airworthiness Directive AD/P166/20 requires the replacement of the hydraulic pressure gauges on Piaggio P166 aeroplanes. (See: \"AD/P166/20 Hydraulic Pressure Gauges - Replacement\".)\n- The directive applies to every Piaggio P166 model. (See: \"Applicability: All model P166.\")\n- The AD points operators to the detailed technical instructions in Piaggio Service Bulletin P166-27. (See: \"Document: Piaggio SB P166-27.\")\n- The timeframe for compliance is immediate: operators must carry out the replacement \"forthwith.\" (See: \"Compliance: Forthwith.\")\n\nWho decides and who must act\n\n- The Civil Aviation Safety Authority issues this directive under the Schedule of Airworthiness Directives. Its issuance makes the replacement mandatory for affected aircraft. (See header: \"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES\" and the AD title.)\n- Aircraft owners and operators of Piaggio P166 models are the parties required to comply with the AD (the AD is applicable to \"All model P166\"). They must follow the technical steps in the referenced Piaggio service bulletin to perform the replacement. (See: \"Document: Piaggio SB P166-27.\")\n\nWhy the document matters (what it changes for operators and maintenance providers)\n\n- The AD creates an immediate, mandatory maintenance task: replacing one component (the hydraulic pressure gauge) across the entire P166 fleet. That changes maintenance scheduling, parts procurement and labour allocation for affected operators.\n- Because the AD refers to an external service bulletin for technical instructions, implementers must consult that Piaggio SB to know which parts to fit and the exact replacement procedure. (See: \"Document: Piaggio SB P166-27.\")\n\nLimitations of the provided text\n\n- The AD text provided does not state the technical or safety reason for the replacement. The text gives the action required, the affected fleet, and the reference to the service bulletin, but not the underlying fault, failure mode, or incident that prompted the AD. (No explanatory rationale appears in the supplied text.)\n\nPractical effects, incentives and trade-offs (source-grounded)\n\n- Who pays: Aircraft owners/operators will bear costs for parts and labour to replace the hydraulic pressure gauges because the AD makes the replacement mandatory for all P166 models. (Inferred from: \"Applicability: All model P166.\" and the nature of an AD.)\n- Compliance burden and timing: The instruction to comply \"forthwith\" imposes urgency; operators may need to interrupt operations or schedule immediate maintenance slots to complete replacements. (See: \"Compliance: Forthwith.\")\n- Where to get technical detail: The AD delegates the exact technical specification and procedures to Piaggio SB P166-27; implementers must obtain and follow that service bulletin to complete the work. The AD by itself does not provide part numbers or detailed steps. (See: \"Document: Piaggio SB P166-27.\")\n- Enforcement and discretion: The AD is issued under CASA's Schedule of Airworthiness Directives, which makes compliance mandatory; the supplied text does not include any exemptions, alternative methods of compliance, or timelines beyond \"forthwith.\" (See header and compliance line.)\n\nConcrete implementation risks and opportunity costs (source-grounded)\n\n- Operational disruption: Immediate compliance may cause short-term aircraft downtime and reallocation of maintenance resources.\n- Procurement and logistics: Operators must source replacement gauges and schedule qualified maintenance personnel; the AD itself does not supply parts or logistics guidance — that will be found in the referenced service bulletin. (See: \"Document: Piaggio SB P166-27.\")\n\nSections cited: \"AD/P166/20 Hydraulic Pressure Gauges - Replacement\", \"Applicability: All model P166.\", \"Document: Piaggio SB P166-27.\", \"Compliance: Forthwith.\", and the CASA Schedule header."}},"importantCases":[],"_links":{"self":"/api/acts/ad-p166-20-hydraulic-pressure-gauges-replacement","history":"/api/acts/ad-p166-20-hydraulic-pressure-gauges-replacement/history","analysis":"/api/acts/ad-p166-20-hydraulic-pressure-gauges-replacement/analysis","conflicts":"/api/acts/ad-p166-20-hydraulic-pressure-gauges-replacement/conflicts","importantCases":"/api/acts/ad-p166-20-hydraulic-pressure-gauges-replacement/important-cases","documents":"/api/acts/ad-p166-20-hydraulic-pressure-gauges-replacement/documents"}}