{"id":"F2006B05328","name":"AD/P166/34 - Landing Gear Selector Valve - Modification","slug":"ad-p166-34-landing-gear-selector-valve-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45793,"registerId":"commonwealth-F2006B05328-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/P166/34 - Landing Gear Selector Valve - 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/P166/34 Landing Gear Selector Valve - Modification 11/68\n\nApplicability: All model P166 fitted with selector valve P/N 5-5233 which does not have the suffix Rev. A on valve name plate.\n\n \n\nDocument: 1. Piaggio SB No. 166-56; or\n\n \n\n2. RAI AD 68-173/P166-31, Rev. 1.\n\n \n\nCompliance: Within 100 hours time in service after 28 November 1968.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD's scope is narrowly targeted and consistent with its stated mechanical purpose: mandate the modification of a specific selector valve part number lacking a particular name‑plate suffix. It neither expands to other components nor broadens applicability beyond the identified aircraft and part number (Applicability; Document; Compliance)."},"complexity_factors":["Narrow applicability: applies only to Piaggio P.166 aeroplanes fitted with selector valve P/N 5-5233 lacking ‘Rev. A’ on the name plate (Applicability).","Single mandated action: requires a single modification rather than a multipart regulatory regime (title/Applicability).","External technical dependency: the AD relies on two external technical documents for the work specification (Piaggio SB No. 166-56; RAI AD 68-173/P166-31, Rev. 1) (Document).","Time-bound compliance: sets a short, specific compliance window (within 100 hours TIS after 28 Nov 1968), which creates scheduling pressure (Compliance).","Regulatory enforcement context: issued under Civil Aviation Regulations 1998, Part 39 — compliance is mandatory and must be recorded (Header)."],"plain_english_summary":"This AD mandates that Piaggio P.166 aircraft fitted with landing‑gear selector valve P/N 5‑5233 whose name plate lacks the suffix \"Rev. A\" must have that valve modified per Piaggio SB No.166‑56 or RAI AD 68‑173/P166‑31 Rev.1. The work must be done within 100 hours TIS after 28 November 1968. It affects owners/operators (who fund and schedule the work) and qualified maintenance organisations or authorised personnel who perform the modification."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued in 1968. It has not expanded beyond its original narrow purpose of addressing a specific defective aircraft component."},"complexity_factors":["Single, clearly defined applicability criterion (specific part number without Rev. A suffix)","Simple binary compliance condition (100 hours time in service from specified date)","No defined terms section or interpretation provisions","No cross-references to other legislation beyond two technical reference documents","No conditional logic, exceptions, or nested provisions","Extremely short document (approximately 150 words of substantive content)"],"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 aircraft** to modify a faulty landing gear component.\n\n**What it does:**\n- **Targets:** All Piaggio P166 model aircraft fitted with a specific landing gear selector valve (part number 5-5233) that does **not** have \"Rev. A\" marked on its nameplate.\n- **Requires:** Modification or replacement of this valve to prevent potential landing gear failures.\n- **Deadline:** Aircraft must be fixed within **100 hours of flying time** after 28 November 1968.\n\n**Why it matters:**\nThe landing gear selector valve controls whether the wheels go up or down. A defective valve could cause the landing gear to malfunction — potentially leading to a wheels-up landing or other serious incident. This AD forces operators to fix the problem before it causes an accident.\n\n**Who must follow this:**\nAnyone operating, maintaining, or owning affected Piaggio P166 aircraft in Australia. Non-compliance is illegal and the aircraft cannot legally fly until fixed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-p166-34-landing-gear-selector-valve-modification","history":"/api/acts/ad-p166-34-landing-gear-selector-valve-modification/history","analysis":"/api/acts/ad-p166-34-landing-gear-selector-valve-modification/analysis","conflicts":"/api/acts/ad-p166-34-landing-gear-selector-valve-modification/conflicts","importantCases":"/api/acts/ad-p166-34-landing-gear-selector-valve-modification/important-cases","documents":"/api/acts/ad-p166-34-landing-gear-selector-valve-modification/documents"}}