{"id":"F2006B05090","name":"AD/CESSNA 180/77 - Aeroquip Engine Exhaust Mufflers","slug":"ad-cessna-180-77-aeroquip-engine-exhaust-mufflers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45067,"registerId":"commonwealth-F2006B05090-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 180/77 - Aeroquip Engine Exhaust Mufflers","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 180, 182 and Wren 460 Series Aeroplanes\n\nAD/CESSNA 180/77 Aeroquip Engine Exhaust Mufflers 7/98 DM\n\nApplicability: Cessna 182S model aircraft incorporating Aeroquip engine exhaust mufflers part number (P/N) 71379-1254017-8.\n\nRequirement: Replace the Aeroquip mufflers in accordance with Cessna Special Service Project SSP98-78-03.\n\nNote: FAA Airworthiness Directive 98-01-14 refers.\n\nCompliance: Effective 6 May 1998; before further flight.\n\nThis airworthiness directive becomes effective on 6 May 1998.\n\nBackground: This directive has been issued to require the removal from service of certain part number Aeroquip engine exhaust mufflers to prevent carbon monoxide contamination of the cabin heating system or the aircraft cabin. The requirement follows advice of certain mufflers produced by Aeroquip may have inadequate or failed welded joints.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive implements the stated original purpose: remove and replace specified Aeroquip mufflers on Cessna 182S aircraft to prevent carbon monoxide contamination by requiring replacement per the manufacturer’s service project. The applicability, required action, and compliance timing align with that purpose as described in the Background, so the legal scope does not change from the instrument’s stated objective."},"complexity_factors":["Narrow applicability: applies only to Cessna 182S aircraft fitted with a single specified Aeroquip muffler part number (Applicability).","Single technical action required: replace the part according to a single manufacturer instruction (Requirement).","Immediate compliance timeline: mandatory 'before further flight' from a specific effective date (Compliance).","Dependence on manufacturer procedure: the technical method is delegated to Cessna Special Service Project SSP98-78-03 (Requirement).","Cross-reference to another regulator's AD (FAA AD 98-01-14), which could require checking an external document (Note).","Operational logistics: potential short-term supply and scheduling burdens for operators, despite simple legal requirement (Compliance; Requirement)."],"plain_english_summary":"The directive mandates removal and replacement of a specific Aeroquip exhaust muffler (P/N 71379-1254017-8) on Cessna 182S aircraft, using Cessna Special Service Project SSP98-78-03, to prevent carbon monoxide entering the cabin or heating system. It is compulsory, effective 6 May 1998, must be done before further flight, and costs are borne by the aircraft owners/operators; enforcement is under the Civil Aviation Safety Authority and it cross‑references FAA AD 98‑01‑14."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive with a narrow, specific safety purpose. It has not expanded beyond its original intent of addressing a specific defective part on specific aircraft models."},"complexity_factors":["Very short document (under 200 words)","Single, unambiguous applicability criterion (specific aircraft model + specific part number)","Single mandatory action (replace mufflers per specified service bulletin)","No defined terms section","No cross-references to other legislation (only references to FAA directive and Cessna service bulletin for technical guidance)","No conditional logic or exceptions","Clear, immediate compliance deadline ('before further flight')"],"plain_english_summary":"This is a **safety order** issued by Australia's Civil Aviation Safety Authority (CASA) that applies to specific Cessna aircraft.\n\n**What it does:**\n- **Targets:** Cessna 182S model planes that have Aeroquip engine exhaust mufflers with part number 71379-1254017-8 installed.\n- **Requires:** Owners/operators must replace these specific mufflers following a Cessna service bulletin (SSP98-78-03).\n- **Why:** Some of these mufflers were made with faulty welds that could crack or fail. If exhaust leaks into the cabin heating system, it can pump **carbon monoxide** (a deadly, odorless gas) into the cockpit.\n\n**Who must act:**\n- Anyone operating a Cessna 182S with the affected muffler part number.\n\n**When:**\n- Immediately — before the aircraft flies again after 6 May 1998.\n\n**Why it matters:**\nCarbon monoxide poisoning in flight can incapacitate or kill pilots and passengers. This directive is an emergency safety measure to prevent accidents caused by defective exhaust components."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-180-77-aeroquip-engine-exhaust-mufflers","history":"/api/acts/ad-cessna-180-77-aeroquip-engine-exhaust-mufflers/history","analysis":"/api/acts/ad-cessna-180-77-aeroquip-engine-exhaust-mufflers/analysis","conflicts":"/api/acts/ad-cessna-180-77-aeroquip-engine-exhaust-mufflers/conflicts","importantCases":"/api/acts/ad-cessna-180-77-aeroquip-engine-exhaust-mufflers/important-cases","documents":"/api/acts/ad-cessna-180-77-aeroquip-engine-exhaust-mufflers/documents"}}