{"id":"F2006B11021","name":"AD/JT9D/28 - LPT Vane Hardware","slug":"ad-jt9d-28-lpt-vane-hardware","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56627,"registerId":"commonwealth-F2006B11021-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JT9D/28 - LPT Vane Hardware","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Pratt and Whitney Turbine Engines - JT9D Series\n\n \n\nAD/JT9D/28 LPT Vane Hardware 1/97\n\nApplicability: All Pratt and Whitney JT9D-7R4 series engines.\n\n \n\nRequirement: Replace certain 5th stage Low Pressure Turbine (LPT) vanes, and 3rd, 4th and 5th stage vane retention hardware in accordance with the technical requirements of FAA AD 96-17-11.\n\n \n\nCompliance: As detailed in the Requirement Document with an effective date of 2 January 1997.\n\n \n\nBackground: There have been reports of failures of LPT vane retention hardware which resulted in uncontained engine failures.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope is the set of engines and parts listed in the instrument itself: \"All Pratt and Whitney JT9D-7R4 series engines\" and specified vane stages/hardware. The document does not indicate any change to that scope from its stated applicability; it mandates the replacement actions described in FAA AD 96-17-11 and sets a compliance framework (Requirement; Applicability; Compliance)."},"complexity_factors":["Cross-reference to an external technical document (FAA AD 96-17-11) creates a dependency on another instrument for implementation details.","Scope limited to a specified engine family and specific vane stages (3rd–5th stage), which narrows applicability but requires technical know-how to identify affected parts.","Mandatory compliance with a fixed effective date requires operational planning by owners/operators (scheduling, procurement, maintenance capacity).","Practical implementation depends on availability of replacement parts and certified maintenance resources, which can vary by operator and region."],"plain_english_summary":"This AD mandates replacement of certain 5th‑stage LPT vanes and 3rd–5th stage vane retention hardware on Pratt & Whitney JT9D‑7R4 engines, following FAA AD 96‑17‑11. It targets operators of those engines to prevent reported vane‑retention failures that led to uncontained engine events. Compliance (by the AD effective date) imposes parts, labour and downtime costs on engine owners."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete safety directive addressing a specific mechanical failure mode in a specific engine series. It has not expanded beyond its original purpose of mandating hardware replacement to prevent uncontained engine failures."},"complexity_factors":["Very short document (under 200 words)","Only 4 substantive sections: Applicability, Requirement, Compliance, and Background","No defined terms section — technical terms (LPT, vane, retention hardware) are used without formal definitions","Single cross-reference to external FAA document (AD 96-17-11) for actual technical requirements","No conditional logic, exceptions, or nested provisions","Straightforward command structure: identify affected engines → replace specific parts → comply by specific date"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA).\n\n**What it does:**\nIt requires owners and operators of specific Pratt & Whitney jet engines (the JT9D-7R4 series) to replace certain parts in the engine's low-pressure turbine section. Specifically, they must swap out:\n- Certain 5th stage turbine vanes (stationary blades that guide airflow)\n- The retention hardware (bolts, brackets, or clips that hold vanes in place) for stages 3, 4, and 5\n\n**Who it affects:**\nAnyone operating aircraft with these specific Pratt & Whitney engines — typically older wide-body jets like early Boeing 747s.\n\n**Why it matters:**\nThe hardware holding these turbine vanes in place has been failing. When this hardware breaks, it can cause \"uncontained engine failures\" — meaning engine parts can break off and pierce the engine casing, potentially damaging the aircraft or injuring passengers. This directive prevents catastrophic engine failures by forcing replacement of the faulty parts before they fail.\n\n**Compliance deadline:**\nOperators had to follow the technical requirements set out in a US Federal Aviation Administration (FAA) directive (AD 96-17-11), with this Australian directive taking effect on 2 January 1997."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt9d-28-lpt-vane-hardware","history":"/api/acts/ad-jt9d-28-lpt-vane-hardware/history","analysis":"/api/acts/ad-jt9d-28-lpt-vane-hardware/analysis","conflicts":"/api/acts/ad-jt9d-28-lpt-vane-hardware/conflicts","importantCases":"/api/acts/ad-jt9d-28-lpt-vane-hardware/important-cases","documents":"/api/acts/ad-jt9d-28-lpt-vane-hardware/documents"}}