{"id":"F2006B11446","name":"AD/P166/2 - Engine Oil System Piping - Re-Routing","slug":"ad-p166-2-engine-oil-system-piping-re-routing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57389,"registerId":"commonwealth-F2006B11446-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/P166/2 - Engine Oil System Piping - Re-Routing","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/P166/2 Engine Oil System Piping - Re-Routing 8/61\n\nApplicability: S/Nos. prior to 362.\n\n \n\nDocument: Piaggio Change Order No. 66-2. 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":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive focused on a specific technical modification for a specific aircraft type. It represents the standard, narrow scope of an individual Airworthiness Directive and shows no evidence of scope creep beyond its original safety purpose."},"complexity_factors":["Extremely short document (under 150 words of substantive content)","Only 2 defined applicability criteria (aircraft model and serial number range)","Single compliance requirement referencing an external technical document","No conditional logic, exceptions, or nested provisions","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","Standardised AD format with minimal regulatory drafting"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific **Piaggio P166 series aircraft** to modify their engine oil system piping.\n\n**What it does:**\n- Orders a physical change to how engine oil pipes are routed in these aircraft\n- Requires compliance with **Piaggio Change Order No. 66-2** (the manufacturer's official modification instruction)\n\n**Who it affects:**\n- Owners and operators of Piaggio P166 aeroplanes with **serial numbers prior to 362**\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety requirements. Non-compliance means the aircraft cannot legally fly.\n- The \"forthwith\" compliance requirement means this must be done **immediately** — not at the next scheduled maintenance.\n- The re-routing likely addresses a safety defect in the original oil system design (such as fire risk, chafing, or failure-prone routing).\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A mandatory regulatory notice requiring aircraft modifications, inspections, or operating limitations to address unsafe conditions.\n- **Change Order:** The manufacturer's official engineering instruction for modifying an aircraft.\n- **Forthwith:** Immediately; without delay."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive sets a specific, narrowly drawn requirement: reroute engine oil system piping on Piaggio P166 aeroplanes with serial numbers prior to 362 and do so in accordance with Piaggio Change Order No. 66-2, to be completed forthwith (Applicability; Document; Compliance). The text contains no indication that the applicability or substantive reach of the requirement has been expanded or narrowed compared with a prior version; therefore there is no evidence in this instrument of a change in scope from any earlier stated intent."},"complexity_factors":["Narrow and clear applicability (serial numbers prior to 362) reduces scope complexity.","Mandatory immediate compliance (‘Forthwith’) increases operational urgency but not legal complexity.","Technical implementation detail is delegated to an external document (Piaggio Change Order No. 66-2), requiring operators to obtain and apply that document.","AD text contains no exceptions, compliance schedule, or alternative methods of compliance, which simplifies legal interpretation but shifts technical judgement to maintainers.","Potential practical complexity arising from maintenance capacity, parts availability and aircraft downtime, none of which are specified in the text."],"plain_english_summary":"Owners and operators of Piaggio P166 aeroplanes with serial numbers prior to 362 must immediately reroute the engine oil system piping in accordance with Piaggio Change Order No. 66-2.  \n\nThis mandatory, forthwith requirement affects aircraft owners/operators (who bear costs and downtime) and the maintenance organisations that will perform the work, and it shifts implementation detail and scheduling burden to those parties."}},"importantCases":[],"_links":{"self":"/api/acts/ad-p166-2-engine-oil-system-piping-re-routing","history":"/api/acts/ad-p166-2-engine-oil-system-piping-re-routing/history","analysis":"/api/acts/ad-p166-2-engine-oil-system-piping-re-routing/analysis","conflicts":"/api/acts/ad-p166-2-engine-oil-system-piping-re-routing/conflicts","importantCases":"/api/acts/ad-p166-2-engine-oil-system-piping-re-routing/important-cases","documents":"/api/acts/ad-p166-2-engine-oil-system-piping-re-routing/documents"}}