{"id":"F2009L03414","name":"AD/TPE 331/29 - Combustion Section - Plenum Chamber Forward Drain Boss - Inspection - CANCELLED","slug":"ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":140992,"registerId":"commonwealth-F2009L03414-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AlliedSignal (Garrett/AiResearch) Turbin","sectionType":"division","heading":"AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series","content":"### AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series\n\n| AD/TPE 331/29 | Combustion Section - Plenum Chamber Forward Drain Boss - Inspection | 10/2009 |\n| ------------- | ------------------------------------------------------------------- | ------- |\n\n| Requirement: | CANCELLED.                                                                                                                                                                |\n| ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|              | This AD is cancelled on 24 September 2009.                                                                                                                                |\n| Background:  | This unique Australian AD specified action in accordance with Airesearch SBNo. 72-0373 within 25 hours time in service after February 1983. The AD is no longer required. |\n\n![](image.001.png)\n\nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n14 August 2009","sortOrder":0},{"sectionNumber":"AD/TPE 331/29","sectionType":"part","heading":"AD/TPE 331/29","content":"## AD/TPE 331/29","sortOrder":1},{"sectionNumber":"Combustion Section - Plenum Chamber Forw","sectionType":"part","heading":"Combustion Section - Plenum Chamber Forward Drain Boss - Inspection","content":"## Combustion Section - Plenum Chamber Forward Drain Boss - Inspection","sortOrder":2},{"sectionNumber":"10/2009","sectionType":"part","heading":"10/2009","content":"## 10/2009","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1946},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":true,"description":"The instrument has transitioned from mandating specific engine inspections to actively cancelling that requirement, effectively removing all compliance obligations for affected operators."},"complexity_factors":["Single administrative action (cancellation)","No defined terms or interpretive provisions","No conditional logic, cross-references, or exceptions","Extremely brief (under 150 words)"],"plain_english_summary":"This document cancels a previous aviation safety rule that required owners and operators of specific AlliedSignal (Garrett/AiResearch) TPE 331 series turbine engines to inspect the **forward drain boss** (a drainage fitting) on the combustion section's plenum chamber.\n\n**What this means:**\n- **Who is affected:** Anyone operating aircraft with TPE 331 series turbine engines (commonly used in regional airliners and utility aircraft).\n- **What changed:** The requirement to perform a specific inspection within 25 hours of service time—based on an old manufacturer service bulletin—is now completely removed.\n- **Why it matters:** This eliminates a compliance burden and maintenance cost for operators, as the safety concern that originally prompted the inspection is no longer considered a risk.\n\nThe cancellation took effect on 24 September 2009."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled","history":"/api/acts/ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled/history","analysis":"/api/acts/ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled/analysis","conflicts":"/api/acts/ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled/conflicts","importantCases":"/api/acts/ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled/important-cases","documents":"/api/acts/ad-tpe-331-29-combustion-section-plenum-chamber-forward-drain-boss-inspection-cancelled/documents"}}