{"id":"F2009L00191","name":"AD/PA-23/46 Amdt 1 - Exhaust System - Inspection and Modification","slug":"ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76639,"registerId":"commonwealth-F2009L00191-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Piper PA-23 (Apache and Aztec) Series Ae","sectionType":"division","heading":"Piper PA-23 (Apache and Aztec) Series Aeroplanes","content":"### Piper PA-23 (Apache and Aztec) Series Aeroplanes\n\n| AD/PA-23/46 Amdt 1 | Exhaust System - Inspection and Modification | 2/2009 |\n| ------------------ | -------------------------------------------- | ------ |\n\n| Applicability: | All models Piper PA-23-250 and PA-E23-250 aircraft with serial numbers 27-2505 and up, equipped with non-supercharged engines.                                                                                                                                                                                                           |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Visually inspect engine exhaust system and alternate air heat shroud in accordance with FAA AD 72-14-05 (amdt 39-1943).2. Adjust and align ball joint stack assemblies and supports in accordance with Piper SB No. 319.Note: FAA AD 72-14-05 (amdt 39-1943) paragraph b. refers.                                                     |\n| Compliance:    | At each scheduled inspection for issue of a maintenance release following the date of effectivity of this amendment.                                                                                                                                                                                                                     |\n|                | This Amendment becomes effective on 12 February 2009.                                                                                                                                                                                                                                                                                    |\n| Background:    | This AD was originally issued in 1971. It specified once-only inspection and modification of the exhaust system in accordance with Piper SB No. 319 within 100 hours time in service after July 1971.This amendment matches FAA AD 72-14-05, including the FAA requirement for periodic inspection at intervals not to exceed 100 hours. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n23 December 2008","sortOrder":0},{"sectionNumber":"AD/PA-23/46 Amdt 1","sectionType":"part","heading":"AD/PA-23/46 Amdt 1","content":"## AD/PA-23/46 Amdt 1","sortOrder":1},{"sectionNumber":"Exhaust System - Inspection and Modifica","sectionType":"part","heading":"Exhaust System - Inspection and Modification","content":"## Exhaust System - Inspection and Modification","sortOrder":2},{"sectionNumber":"2/2009","sectionType":"part","heading":"2/2009","content":"## 2/2009","sortOrder":3}],"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The amendment expands scope relative to the original AD by converting the prior once-only inspection/modification into a recurring inspection regime at intervals not to exceed 100 flight hours, aligning with FAA AD 72-14-05 (Background). This shifts recurring inspection and adjustment costs and labour onto aircraft owners/operators and ties compliance timing to scheduled maintenance releases (Compliance)."},"complexity_factors":["Cross-reference to external FAA AD 72-14-05 and Piper SB No. 319 creates dependency on external documents for procedural detail (Requirement).","Change from a single retrofit to recurring inspections at intervals not to exceed 100 hours increases ongoing compliance burden and costs for operators (Background; Compliance).","Applicability limited by model, serial-number floor and engine type narrows scope but requires accurate aircraft identification (Applicability).","Timing tied to each scheduled maintenance-release may create variability in inspection intervals depending on operators' maintenance schedules (Compliance).","Requirement includes both visual inspection and mechanical adjustment/alignment of ball-joint assemblies, requiring qualified maintenance labour and potential parts (Requirement).","Effective date and amendment history require operators to reconcile prior compliance actions with the new recurring requirement (Background; Amendment effective date).","Recordkeeping and proof of compliance likely needed for continued airworthiness certification and releases (implicit in Compliance)."],"plain_english_summary":"This amendment requires owners/operators of specified Piper PA-23-250 and PA-E23-250 aeroplanes (serials 27-2505 and up, non-supercharged) to visually inspect the engine exhaust system and alternate-air heat shroud and to adjust/align ball-joint stack assemblies/supports to the standards in FAA AD 72-14-05 and Piper Service Bulletin No. 319. Compliance must occur at each scheduled maintenance-release inspection and adopts a recurring inspection interval not to exceed 100 flight hours, changing the requirement from a one‑off check to ongoing maintenance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The amendment maintains the original scope (exhaust system safety for specific Piper aircraft). The only change is operational: converting a one-time inspection requirement into a recurring inspection requirement to align with FAA standards. This is a procedural tightening, not scope expansion."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements (visual inspection and adjustment)","Minimal defined terms (relies on external references to FAA AD and Piper Service Bulletin)","Simple compliance trigger (at each scheduled inspection)","No nested exceptions or conditional logic","Single amendment updating a 1971 directive with straightforward change from one-time to recurring inspection"],"plain_english_summary":"This CASA Airworthiness Directive mandates recurring inspections and corrective alignment of the engine exhaust and alternate-air heat shroud on certain Piper Apache/Aztec (PA-23-250/PA-E23-250, SN 27-2505+) with non‑supercharged engines, effective from 12 Feb 2009 to match updated FAA standards. It converts a 1971 one‑time fix into regular checks (≤100 flight hours) to prevent exhaust failures that can cause carbon monoxide cabin leaks or engine damage. Affects aircraft owners, operators and maintenance engineers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification","history":"/api/acts/ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification/history","analysis":"/api/acts/ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification/important-cases","documents":"/api/acts/ad-pa-23-46-amdt-1-exhaust-system-inspection-and-modification/documents"}}