{"id":"F2006B08673","name":"AD/CT58/15 - Inspection/Replacement of Rotating Parts","slug":"ad-ct58-15-inspection-replacement-of-rotating-parts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51777,"registerId":"commonwealth-F2006B08673-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nGeneral Electric Turbine Engines \\- CT58 Series","sortOrder":0},{"sectionNumber":"AD/CT 58/15 Inspection/Replacement of Ro","sectionType":"part","heading":"AD/CT 58/15 Inspection/Replacement of Rotating Parts 5/2002","content":"# AD/CT 58/15 Inspection/Replacement of Rotating Parts 5/2002\n\nDM\n\nApplicability: Models CT58-100-2, \\-110-1, 110-2, \\-140-1, \\-140-2, and T58-GE-3/-5/-8F/-10/-100\n\nseries turboshaft engines\n\nRequirement: 1. Inspect/replace the various rotating components in accordance with FAA AD 97-19-17 with the exception of engine cooling plates:\n\n    Stage 1 front cooling plates, P/N: 37C300055P101;\n    Stage 2 front cooling plates, P/N: 3000T88P02; and\n    Stage 2 aft cooling plates, P/N: 30002T27P01.\n\n2. For cooling plates listed in Requirement 1 above, and identified by serial number in GE Aircraft Engines CT58 Service Bulletin (SB) 72-188 (CEB-293), Revision 1, dated 15 July, 1997, replace with serviceable parts.\n\nNote 1: FAA AD 97-21-08 refers to Requirement 2 of this Airworthiness Directive.\n\nNote 2: GE Aircraft Engines Service Bulletins (SB) (CT58): A72-162 (CEB- 258), Revision 8, dated 16 June, 1997; 72-181 (CEB-284) Revision 2, dated 15\n\nJuly1997, and 72-188 (CEB-293) Revision 1, dated 15 July, 1997 refer.\n\nCompliance: For Requirement 1: Unless already accomplished, at the compliance periods required by FAA AD 97-19-17 from the effective date of this Airworthiness Directive.\n\nFor Requirement 2: Unless already accomplished, at the next exposure, or next light overhaul, whichever occurs first, but not to exceed 1,000 hours Time in Service (TIS) for engines installed on aircraft that have engaged in Repetitive Heavy Lift (RHL) operations, or 2,000 hours TIS for engines installed on aircraft that have never engaged in RHL operations, in accordance with CT58 Service Bulletin (SB) 72-188 (CEB-293) Revision 1, dated 15 July, 1997 from the effective date of this Airworthiness Directive.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This AD largely adopts FAA AD 97-19-17 for inspecting/replacing rotating parts but modifies scope for certain cooling plates: it excludes those cooling plates from the FAA AD procedure and imposes a separate mandatory replacement requirement tied to serial numbers listed in GE SB 72-188 Rev 1. It also adds differentiated compliance hour limits for RHL versus non-RHL operations, so the instrument changes the FAA-based scope for those cooling-plate items and the timing rules operators must follow."},"complexity_factors":["Cross-references to external mandatory documents: FAA AD 97-19-17 and FAA AD 97-21-08, and GE Service Bulletins (SB 72-162, 72-181, 72-188 Rev 1), requiring operators to consult multiple texts.","Exception carve-out: the AD adopts FAA AD procedures but explicitly excludes certain cooling plates and replaces that treatment with a separate serial-numbered replacement requirement.","Serial-number based scope for cooling plates (identified in SB 72-188 Rev 1), which requires tracking individual parts rather than only part numbers.","Differentiated compliance timing tied to operational use: shorter maximum Time in Service (1,000 TIS) for engines that have done Repetitive Heavy Lift (RHL) versus 2,000 TIS for others.","Timing rule complexity: Requirement 2 triggers at next exposure or next light overhaul, whichever occurs first, creating monitoring and scheduling obligations.","Applicability across multiple engine models (CT58-100-2, -110-1, -110-2, -140-1, -140-2 and T58-GE-3/-5/-8F/-10/-100), increasing the population of affected operators."],"plain_english_summary":"This Airworthiness Directive requires operators of aircraft fitted with General Electric CT58/T58 series turboshaft engines to inspect and, where necessary, replace specified rotating components by following FAA AD 97-19-17 procedures, except for certain engine cooling plates. Those cooling plates are singled out for replacement if their serial numbers appear in GE Service Bulletin 72-188 Rev 1. It matters because it creates mandatory maintenance deadlines, different hour limits depending on Repetitive Heavy Lift (RHL) use, and shifts inspection, replacement cost and scheduling obligations onto aircraft operators."},"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":4,"scope_assessment":{"changed":false,"description":"This AD appears focused on its original safety purpose — addressing specific rotating component failures in CT58 engines. The structure (applicability, requirement, compliance) follows standard AD format without apparent scope creep. The reference to external FAA ADs and manufacturer service bulletins is typical for aviation safety instruments rather than expansion beyond original intent."},"complexity_factors":["Multiple cross-references to external documents: FAA AD 97-19-17, FAA AD 97-21-08, and three separate GE Service Bulletins (SB 72-188, A72-162, 72-181) that operators must obtain and follow","Nested exception structure: Requirement 1 excludes specific part numbers, then Requirement 2 creates a separate compliance regime just for those excluded parts","Dual compliance timelines based on operational category: 1,000 hours TIS for Repetitive Heavy Lift (RHL) operations vs 2,000 hours TIS for non-RHL operations","Technical aviation terminology requiring specialized knowledge: 'Time in Service (TIS)', 'light overhaul', 'exposure', 'serviceable parts', part numbers with specific formats","Conditional compliance triggers: 'next exposure', 'next light overhaul', 'whichever occurs first' creating interdependent deadlines"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspections and timely replacement of certain rotating parts in specified General Electric CT58/T58 turboshaft engines to prevent cracks or failures that could lead to engine loss. It affects operators of helicopters and other aircraft using those engine models.\n\nIt also requires replacement of particular cooling-plate parts with listed serial numbers within shorter intervals for heavy‑lift operations, reflecting their higher fatigue risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ct58-15-inspection-replacement-of-rotating-parts","history":"/api/acts/ad-ct58-15-inspection-replacement-of-rotating-parts/history","analysis":"/api/acts/ad-ct58-15-inspection-replacement-of-rotating-parts/analysis","conflicts":"/api/acts/ad-ct58-15-inspection-replacement-of-rotating-parts/conflicts","importantCases":"/api/acts/ad-ct58-15-inspection-replacement-of-rotating-parts/important-cases","documents":"/api/acts/ad-ct58-15-inspection-replacement-of-rotating-parts/documents"}}