{"id":"F2006B08279","name":"AD/CESSNA 340/33 - Exhaust System Components - Inspection","slug":"ad-cessna-340-33-exhaust-system-components-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115596,"registerId":"commonwealth-F2006B08279-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 340/33 - Exhaust System Components - Inspection","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 340 Series Aeroplanes\n\nAD/CESSNA 340/33 Exhaust System Components \\- Inspection 1/99 TX\n\nApplicability: Model 340A aeroplanes, serial numbers 215 through 1817 that have had an exhaust system WYE tube changed since 01 May 1998.\n\nRequirements: 1. Establish the part number of the exhaust system WYE tube fitted to the aircraft by search of the aircraft records or by physical examination of the component.\n\n2. Remove and replace exhaust system WYE tubes P/N 9910299-25 or P/N 9910299- 26 with exhaust system WYE tubes P/N 9910299-8 (for P/N 9910299-25) or P/N 9910299-9 (for P/N 9910299-26) or any other WYE tube that is approved by the aircraft manufacturer.\n\nNote: US FAA Priority Letter 98-24-14 dated 13 November 1998 refers.\n\nCompliance: 1. Before further flight after receipt of this Airworthiness Directive.\n\n2. Before further flight if defective components are identified.\n\nThis Airworthiness Directive becomes effective on 20 November 1998.\n\nBackground: The FAA has received reports of five instances where the engine exhaust components in the WYE tube installed on certain Cessna aircraft were manufactured without welds. These non-welded areas lead to leaks in the exhaust system on the turbocharged engine installations on these aeroplanes. The heat from the leaks in the exhaust system have caused aluminium fuel lines located immediately behind the firewall to burst. This condition has come about due to a quality control problem at a sub contractor. Cessna has returned all existing inventory to the sub contractor, however it is known that approximately 25 WYE tubes have been distributed to the field since May 1998. This Directive issues instructions to identify and remove from service the defective components. This defect is considered to be an urgent safety of flight issue and hence the inspection must be completed before further flight.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in a specific aircraft component. The document is a standalone safety directive with no evidence of scope creep from its original purpose of grounding aircraft with defective exhaust components."},"complexity_factors":["Single, specific mechanical component targeted (WYE tube)","Narrow applicability: only one aircraft model (Cessna 340A), specific serial number range, and conditional on maintenance history since 1 May 1998","Simple binary compliance: identify part number → replace if matches listed defective parts","No nested exceptions, conditional logic, or cross-references to other legislation beyond a single FAA reference note","Clear, immediate compliance deadline (before further flight)","Only 2 defined part numbers to identify and 2 replacement options specified"],"plain_english_summary":"This AD grounds certain Cessna 340A aeroplanes (S/N 215–1817) until owners/operators inspect the exhaust WYE tube — or check records — if it was changed since 1 May 1998. \n\nIt addresses WYE tubes made without proper welds that can leak exhaust, overheat and burst nearby aluminium fuel lines. If the installed part is P/N 9910299-25 or -26, it must be removed and replaced before further flight."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope is limited and specific: it targets certain Cessna 340A serial numbers that had a WYE tube changed after 1 May 1998 and mandates identification and replacement of specified part numbers. The instrument does not expand to other models, serials, or components beyond the stated WYE tubes."},"complexity_factors":["Narrow applicability: applies only to Model 340A serial numbers 215–1817 with a WYE tube changed since 1 May 1998 (Applicability).","Identification step requires record search or physical inspection to determine part number (Requirements 1).","Replacement mandate names specific part numbers and allows only manufacturer‑approved alternatives, creating reliance on manufacturer approval processes (Requirements 2).","Immediate compliance required: inspection/replacement must occur before further flight, increasing operational disruption risk (Compliance).","Potential supply/logistics constraint if replacement WYE tubes are scarce given limited affected population (Background/Requirements).","Enforcement and liability rest with operators; costs (inspection, removal/installation, aircraft downtime) are borne by operators (Requirements/Compliance).","Reference to FAA Priority Letter indicates coordination with overseas authority but does not change domestic procedural steps (Note)."],"plain_english_summary":"This directive requires operators of Cessna 340A aeroplanes (serials 215–1817) that had a WYE exhaust tube changed since 1 May 1998 to identify the fitted part and, if it is P/N 9910299-25 or -26, replace it with the specified P/N 9910299-8 or -9 or a manufacturer-approved equivalent before the next flight. Operators must pay for inspection and any replacement; the regulator enforces compliance because faulty (non‑welded) WYE tubes can leak and overheat nearby aluminium fuel lines."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-340-33-exhaust-system-components-inspection","history":"/api/acts/ad-cessna-340-33-exhaust-system-components-inspection/history","analysis":"/api/acts/ad-cessna-340-33-exhaust-system-components-inspection/analysis","conflicts":"/api/acts/ad-cessna-340-33-exhaust-system-components-inspection/conflicts","importantCases":"/api/acts/ad-cessna-340-33-exhaust-system-components-inspection/important-cases","documents":"/api/acts/ad-cessna-340-33-exhaust-system-components-inspection/documents"}}