{"id":"F2010L02455","name":"AD/PW4000/17 - Turbine Exhaust Case","slug":"ad-pw4000-17-turbine-exhaust-case","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":84392,"registerId":"commonwealth-F2010L02455-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pratt and Whitney Turbine Engines - PW40","sectionType":"division","heading":"Pratt and Whitney Turbine Engines - PW4000 Series","content":"### Pratt and Whitney Turbine Engines - PW4000 Series\n\n| AD/PW4000/17 | Turbine Exhaust Case | 19/2010 |\n| ------------ | -------------------- | ------- |\n\n| Applicability: | Pratt and Whitney PW4000 engines as specified by models in FAA AD 2003-26-09.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Unless already accomplished perform the initial inspections in accordance with the technical requirements of FAA AD 2003-26-09.Repeat the inspections in accordance with the technical requirements of FAA AD 2003-26-09.Later revisions to PW ASB PW4G-112-A72-257, Revision 1, dated 22 August 2003, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2003-26-09, are considered acceptable for compliance with the equivalent Requirements of this AD.                                                                                                                           |\n| Compliance:    | As specified in the Requirement Document with a revised effective date of20 September 2010.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n|                | This Airworthiness Directive becomes effective on 20 September 2010.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background:    | There have been of reports of engine high pressure turbine (HPT) assembly hardware being damaged as a result of thermal distress from oil igniting after leaking from the No. 3 bearing compartment. This AD is issued to prevent thermal distressed HPT assembly hardware from remaining in service, which could result in a cracked HPT stage 1 disc and HPT stage 1-2 air seal and an uncontained engine failure.CASA appreciates that although this AD may not be applicable to any aircraft presently registered in Australia, it will ensure applicability for aircraft entering the Australian register in the future with this engine configuration. |\n\n![](image.001.png)\n\nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n9 September 2010","sortOrder":0},{"sectionNumber":"AD/PW4000/17","sectionType":"part","heading":"AD/PW4000/17","content":"## AD/PW4000/17","sortOrder":1},{"sectionNumber":"Turbine Exhaust Case","sectionType":"part","heading":"Turbine Exhaust Case","content":"## Turbine Exhaust Case","sortOrder":2},{"sectionNumber":"19/2010","sectionType":"part","heading":"19/2010","content":"## 19/2010","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD adopts the inspection requirements of FAA AD 2003-26-09 and accepts an AMOC via a Pratt & Whitney service bulletin revision; it does not expand or narrow those technical requirements. CASA explicitly notes the AD may not apply to current Australian-registered aircraft but ensures the same requirements will apply to any future registrants with these engines (Requirement; Background)."},"complexity_factors":["References an external instrument (FAA AD 2003-26-09) for the technical inspection requirements rather than reproducing them (Applicability; Requirement) — operators must consult another document to know exact tasks.","Accepts later revisions to a Pratt & Whitney service bulletin as an Alternate Method of Compliance (AMOC), introducing regulator discretion over acceptable compliance pathways (Requirement).","Mandates recurring inspections (Requirement), creating ongoing operational and cost implications rather than a one-off action.","Sets a fixed effective date (20 September 2010) which creates a clear compliance timeline (Compliance).","Background notes limited present applicability to Australian-registered aircraft but preserves applicability for future registrants, affecting who must comply in practice (Background).","Technical subject matter (turbine exhaust case, HPT assembly, oil ignition risks) is specialized; although not detailed here, compliance requires technical maintenance capability and possibly parts/overhaul scheduling (Background; Requirement)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Pratt & Whitney PW4000 engines listed in FAA AD 2003-26-09 to carry out the initial and recurring turbine exhaust case inspections specified in that FAA AD. CASA accepts a later PW service bulletin revision (PW4G-112-A72-257 Rev 1) as an alternate method of compliance. It takes effect 20 September 2010 and applies to operators of the listed engines, who must schedule and pay for the inspections to address oil-ignition thermal damage risks."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a clear, narrow safety purpose. It has not expanded beyond its original intent of addressing the specific turbine exhaust case thermal distress issue identified in the FAA's original 2003 directive."},"complexity_factors":["Short, single-purpose safety directive (approximately 300 words)","Only 1 defined term implicitly referenced (FAA AD 2003-26-09)","Simple conditional structure: 'Unless already accomplished, do X'","Heavy reliance on external technical documents (FAA AD and Pratt & Whitney service bulletin) rather than spelling out inspection procedures in the text itself","No nested exceptions or complex legislative cross-references — references only to US aviation safety rules","Clear, single compliance date with straightforward applicability criteria"],"plain_english_summary":"This AD mandates inspections of the turbine exhaust case on certain Pratt & Whitney PW4000 engines to detect heat damage from No. 3 bearing oil leaks that can lead to cracked turbine discs and uncontained engine failure. \n\nIt affects operators and maintenance organisations using these engines (common on some Boeing and Airbus types) and requires initial and recurring inspections per FAA AD 2003-26-09, with FAA‑approved alternative methods acceptable — preventing potentially catastrophic, debris‑causing failures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw4000-17-turbine-exhaust-case","history":"/api/acts/ad-pw4000-17-turbine-exhaust-case/history","analysis":"/api/acts/ad-pw4000-17-turbine-exhaust-case/analysis","conflicts":"/api/acts/ad-pw4000-17-turbine-exhaust-case/conflicts","importantCases":"/api/acts/ad-pw4000-17-turbine-exhaust-case/important-cases","documents":"/api/acts/ad-pw4000-17-turbine-exhaust-case/documents"}}