{"id":"F2006B08331","name":"AD/CESSNA 400/45 - Exhaust Tailpipe Support Kit - Installation","slug":"ad-cessna-400-45-exhaust-tailpipe-support-kit-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115738,"registerId":"commonwealth-F2006B08331-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/45 - Exhaust Tailpipe Support Kit - Installation","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)  Cessna 400 Series Aeroplanes\n\n \n\nAD/CESSNA 400/45 Exhaust Tailpipe Support Kit - Installation 10/75\n\nApplicability: Model 401 with S/Nos. 401-0001 to 401B0300. Model 402 with S/Nos. 402-0001 to 402B0300. Model 414 with S/Nos. 414-0001 to 414-0350. Model 421 with S/Nos.\n\n421-0001 to 421B0300.\n\n \n\nDocument: Cessna SL ME75-17, Category No. 111. Compliance: Before 1 January 1976.\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 directive prescribes a single, specific action (installation of the Exhaust Tailpipe Support Kit) for clearly enumerated models and serial-number ranges, to be completed by a fixed date. The supplied text contains no indication that the scope has been expanded or narrowed from an earlier version; it sets the requirement, the referenced installation document, and the compliance date and nothing in the text suggests a change from an earlier intent."},"complexity_factors":["Narrow applicability: specific models and serial-number ranges are listed (Applicability).","Fixed compliance deadline: an absolute date is set (Compliance: Before 1 January 1976).","Technical detail delegated to an external document (Cessna SL ME75-17, Category No. 111), requiring operators to obtain and follow that document.","No discretionary routes, waivers, or alternative compliance procedures are stated in the supplied text.","Logistical complexity for operators (sourcing kit and arranging installation) despite the directive's simple prescription."],"plain_english_summary":"### What this instrument does, in plain English\n\nThis is an airworthiness directive titled \"AD/CESSNA 400/45 — Exhaust Tailpipe Support Kit - Installation\". It requires that a specific Exhaust Tailpipe Support Kit be installed on certain Cessna 400-series aeroplanes identified by model and serial-number ranges. The requirement is set out in a referenced Cessna document (\"Cessna SL ME75-17, Category No. 111\") and must be complied with before 1 January 1976.\n\n- Who is affected: Owners/operators of the listed aeroplane models and serial numbers (see the directive's Applicability: \"Model 401 with S/Nos. 401-0001 to 401B0300; Model 402 with S/Nos. 402-0001 to 402B0300; Model 414 with S/Nos. 414-0001 to 414-0350; Model 421 with S/Nos. 421-0001 to 421B0300\").\n- What they must do: Obtain and install the Exhaust Tailpipe Support Kit according to the referenced Cessna service/document (\"Cessna SL ME75-17, Category No. 111\") and complete the work before the date specified (\"Compliance: Before 1 January 1976\").\n\n### Mechanism and how it works\n\n- The directive identifies affected aircraft by model and serial-number ranges (text under \"Applicability\").\n- Compliance is time-limited: the installation must be done on or before the stated compliance date (text under \"Compliance\").\n- The technical details, parts and installation procedure are given in the referenced document (\"Document: Cessna SL ME75-17, Category No. 111\"). The directive thus makes that external document the operative instruction for how to carry out the work.\n\n### Stated purpose and what the text actually says\n\n- The instrument is issued as part of the \"Schedule of Airworthiness Directives,\" which identifies mandatory maintenance or modification actions for airworthiness. The directive itself sets the mandatory action and deadline but does not include a narrative explanation in the text supplied here describing the specific problem it addresses.\n\n### Who pays, who decides, and who changes behaviour\n\n- Who pays: The owners/operators of the affected aircraft will bear the costs of acquiring the kit and having it installed (the directive requires them to perform the work; the text does not allocate funding).\n- Who decides: The Civil Aviation Safety Authority published the directive; compliance requires following the procedural details in the referenced Cessna document. There is no discretionary alternative or waiver described in the text provided.\n- Behaviour changes: Operators must schedule and complete the installation before the deadline and follow the referenced service documentation when performing the work.\n\n### Compliance burden, discretion and implementation risk\n\n- Compliance burden: Operators must locate the referenced Cessna document (\"Cessna SL ME75-17, Category No. 111\"), obtain the kit, and arrange installation before the specified date. The text does not quantify time or cost.\n- Bureaucratic discretion: The directive is prescriptive (lists specific models/serial numbers and a fixed compliance date). The text supplied does not set out any discretionary exemptions, alternative methods of compliance, or processes for approval of different procedures.\n- Implementation risks and trade-offs: The directive implicitly requires logistics (sourcing the kit and qualified maintenance labour) within the time window. If kits or parts are limited, operators could face scheduling delays. The directive ties compliance to a particular external document for technical detail, so errors or ambiguities in that document could affect correct implementation (see \"Document: Cessna SL ME75-17, Category No. 111\").\n\n### Market and contractual effects to note\n\n- Private operators lose some freedom to defer or substitute different modifications for the affected tailpipe support because the directive mandates a particular kit and references the manufacturer document for installation.\n- The cost and scheduling burden is concentrated on the listed aircraft owners/operators; the directive does not indicate any cost-sharing or subsidy.\n\n(References in text: \"Applicability\", \"Document: Cessna SL ME75-17, Category No. 111\", \"Compliance: Before 1 January 1976\".)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of mandating exhaust system modifications for the identified Cessna models."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 4 defined applicability ranges (serial number ranges for 4 aircraft models)","Single compliance requirement with one deadline","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","No conditional logic, exceptions, or nested provisions","Straightforward mandate: install specific part by specific date"],"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 Cessna 400-series aircraft to install an **exhaust tailpipe support kit** to prevent dangerous failures.\n\n**Who it affects:**\n- Owners and operators of specific Cessna models with particular serial numbers:\n  - **Model 401** (serial numbers 401-0001 to 401B0300)\n  - **Model 402** (serial numbers 402-0001 to 402B0300)\n  - **Model 414** (serial numbers 414-0001 to 414-0350)\n  - **Model 421** (serial numbers 421-0001 to 421B0300)\n\n**What it requires:**\n- Install a specific support kit for the exhaust tailpipe (the pipe that carries hot exhaust gases away from the engine), following Cessna Service Letter ME75-17.\n\n**Why it matters:**\n- Exhaust system failures can cause carbon monoxide poisoning (a deadly, odorless gas that can leak into the cabin), engine damage, or fire. This directive prevents those risks by strengthening the exhaust system.\n\n**Deadline:**\n- The work must be completed **before 1 January 1976** (note: this is a historical directive from 1975)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-45-exhaust-tailpipe-support-kit-installation","history":"/api/acts/ad-cessna-400-45-exhaust-tailpipe-support-kit-installation/history","analysis":"/api/acts/ad-cessna-400-45-exhaust-tailpipe-support-kit-installation/analysis","conflicts":"/api/acts/ad-cessna-400-45-exhaust-tailpipe-support-kit-installation/conflicts","importantCases":"/api/acts/ad-cessna-400-45-exhaust-tailpipe-support-kit-installation/important-cases","documents":"/api/acts/ad-cessna-400-45-exhaust-tailpipe-support-kit-installation/documents"}}