{"id":"F2026L00328","name":"AD/ENG/5 Amdt 10 – Turbine Engine Continuing Airworthiness Requirements","slug":"ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":107876,"registerId":"commonwealth-F2026L00328-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Engines - General","sectionType":"part","heading":"Engines - General","content":"# Engines - General\n\n| AD/ENG/5 Amdt 10 | Turbine Engine Continuing Airworthiness Requirements | 6/2026 |\n| ---------------- | ---------------------------------------------------- | ------ |\n\n| Applicability: | All turbine engines; other than engines installed in:1. Aircraft administered by an approved sports aviation body; and2. Aircraft issued with a limited category certificate of airworthiness under regulation 21.189 of the CASR; and3. Aircraft issued with an experimental certificate under regulation 21.195A of the CASR.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. OVERHAUL/INSPECTION PERIODS FOR TURBINE ENGINES1.1 Turbine engines must be overhauled or inspected at periods not exceeding:(a) those detailed in Requirements 1.2, 1.3 and 1.4 of this Directive; or(b) the recommended hours in service published by the engine manufacturer; or(c) those detailed in a system of maintenance approved under regulation 42M of the Civil Aviation Regulations 1988 (an approved system of maintenance).1.2 Honeywell TPE331 series engines must be:(a) overhauled at the periods specified in, and subject to the requirements of, the latest revision of the Honeywell Service Bulletin detailing TPE331 series engine time between overhaul (TBO) intervals and requirements that applies to the engine model (for the purpose of this AD, annual utilisation, or type of operation, are not requisites to establish a TBO period for Honeywell TPE331-1, -2, -3, -5, -6, -8, -10, -11, -12 series engines); or(b) inspected in accordance with, and subject to the requirements of, the latest version of a Honeywell published Continuous Airworthiness Maintenance Operation (CAM) program that applies to the engine model (for the purpose of this AD, annual utilisation, or type of operation, are not requisites to establish a TBO period for Honeywell TPE331-1, -2, -3, -5, -6, -8, -10, -11, -12 series engines); or(c) inspected and overhauled as detailed in an approved system of maintenance. |\n\n|             | 1.3 Pratt and Whitney Canada PT6A series engines, other than PT6A engines installed in aircraft conducting aerial agricultural operations or fire-fighting operations, must be:(a) overhauled at the periods specified in, and subject to the requirements of, the latest revision of the Pratt and Whitney Canada Service Bulletin detailing Pratt and Whitney Canada PT6A operating time between overhaul and hot section inspection frequency that applies to the engine model; or(b) overhaul at periods not to exceed 5,000 hours time in service, subject to compliance with the maintenance requirements detailed in Appendix A of this AD; or(c) inspected and overhauled as detailed in an approved system of maintenance.1.4 Pratt and Whitney Canada PT6A series engines installed in aircraft conducting aerial agricultural operations or fire-fighting operations must be:(a) overhauled at the periods as specified in, and subject to the requirements of, the latest revision of the Pratt and Whitney Canada Service Bulletin detailing Pratt and Whitney Canada PT6A operating time between overhaul and hot section inspection frequency that applies to the engine model; or(b) inspected in accordance with an engine on-condition program having regard to that detailed in Appendix B of this AD; or(c) inspected, overhauled and “on-condition” monitor as detailed in an approved system of maintenance.Previously issued Alternative Means of Compliances (AMOCs) or Exclusions to AD/ENG/5 Amdt 9 are considered acceptable for compliance with the equivalent requirements of this AD. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance  | No later than 30 June 2026This Amendment becomes effective on 31 March 2026                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background: | Amendment 10 of this AD has been issued to remove an obsolete reference to Pratt and Whitney Canada SIL PT6A-122 and replace it with a reference to Revision 10 (Pratt and Whitney Canada SIL No. GEN-055 R10 dated 13 November 2018), the latest version of this Service Information Letter as at the commencement of this AD.The AD is issued to address an unsafe situation relating to turbine engines by requiring turbine engines to be overhauled or inspected at specified intervals. The unsafe condition, if not addressed, could result in loss of power, uncontained release of debris, damage to the engine, and damage to the aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n\n| Background (continued): | This AD does not apply in relation to turbine engines installed in certain, specified aircraft. This AD addresses the engine certification requirement to publish instructions for the continued airworthiness of a type-certificated engine. In addition to listing the manufacturer’s published TBO or inspection periods, this AD also provides unique CASA initiated options for certain turbine engines. |\n| ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![David Punshon's signature.](image.001.jpeg)\n\nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n18 March 2026\n\n  \n\n| AD/ENG/5 Amdt 10 | PT6A Enhanced Maintenance Program | Appendix A |\n| ---------------- | --------------------------------- | ---------- |\n\nREQUIREMENTS\n\nThe PT6A engine maintenance program must be carried out in accordance with approved maintenance data and detailed in an approved system of maintenance. The system of maintenance must include, but need not be limited to, the following requirements:\n\n1. PT6A engines not previously maintained in accordance with a maintenance program reflecting the intent of the maintenance requirements detailed in this Appendix and with engine hours in service greater than 75% of the Pratt and Whitney Canada published Time Between Overhaul (TBO) period at the time of introduction, must be subject to a pro-rata TBO period based on the Pratt and Whitney Canada published TBO period.\n\n2. The engine must be on an Engine Condition Trend Monitoring (ECTM) program, including data collection, analysis and follow up actions. This program must be in accordance with the WebECTM® system or CAMP Systems International (CAMP), as required under revision 10 of Pratt and Whitney Canada SIL No. GEN-055 (PWC SIL No. GEN-055 R10 dated 13 November 2018), as existing at the commencement of this instrument, and include requirements for qualification and training for personnel conducting ECTM.\n\n3. Hot section inspections must be carried out at intervals not to exceed:\n\n(a) 1250 hours time in service; or\n\n(b) 1760 hours time in service subject to a boroscope inspection of the engine hot section for evidence of cracks, distortion, burning and coating loss at intervals not to exceed 610 hours time in service.\n\n4. All fuel nozzles must be cleaned and flow checked at intervals not to exceed 460 hours time in service.\n\n5. The engine oil filter element must be inspected for contamination at intervals not to exceed 220 hours time in service.\n\n6. The reduction gearbox chip detector must be inspected for contamination, or continuity, at intervals not to exceed 220 hours time in service.\n\n7. Engines with an annual utilisation of less than 500 hours per annum, an engine oil change must be carried out at intervals not to exceed 12 calendar months time in service.\n\n8. An inspection of the 1st stage compressor for evidence of Foreign Object damage (FOD), corrosion and contamination must be carried out at intervals not to exceed 220 hours time in service.\n\n9. A compressor power recovery wash must be carried out in response to trend monitoring parameter deviations, or at intervals not to exceed 220 hours time in service, or 3 calendar months, whichever occurs first.\n\n10. All life limited components must be replaced at engine manufacturer’s published life limits per AD/ENG/7.\n\n11. Critical components, as identified in the Pratt and Whitney Service Bulletin that applies to the engine model, must be inspected at intervals specified by the engine manufacturer.\n\n12. TBO of accessories must be per the recommendations of Pratt and Whitney Canada.\n\n13. The maintenance program must be reviewed and revised as required at periods not to exceed 2 years taking into consideration all major defects and defects that affect engine durability. Outcome of the review must be reported to CASA via CASA’s online Defect Reporting System (DRS) Portal or via Form 404 referring to AD/ENG/5.\n\n  \n\n| AD/ENG/5 Amdt 10 | PT6A Agricultural OperationsOn-Condition Maintenance Program | Appendix B |\n| ---------------- | ------------------------------------------------------------ | ---------- |\n\nREQUIREMENTS\n\nThe PT6A engine on-condition maintenance program must be carried out in accordance with approved maintenance data and detailed in an approved system of maintenance. The system of maintenance must include, but need not be limited to, the following requirements:\n\n1. The engine must be on an Engine Condition Trend Monitoring (ECTM) program, including data collection, analysis and follow up actions, qualification and training of personnel. This program must be in accordance with the WebECTM® system or CAMP Systems International (CAMP), as required under revision 10 of Pratt and Whitney Canada SIL No. GEN-055 (PWC SIL No. GEN-055 R10 dated 13 November 2018), and include requirements for qualification and training for personnel conducting ECTM.\n\n2. Hot section inspections must be carried out at intervals not to exceed 1510 hours time in service.\n\n3. All fuel nozzles must be cleaned and flow checked at intervals not to exceed 460 hours time in service.\n\n4. The engine oil filter element must be inspected for contamination at intervals not to exceed 220 hours time in service.\n\n5. The reduction gearbox chip detector must be inspected for contamination, or continuity, at intervals not to exceed 220 hours time in service.\n\n6. Engines with an annual utilisation of less than 500 hours per annum, an engine oil change must be carried out at intervals not to exceed 12 calendar months time in service.\n\n7. Engines not incorporating an engine air intake positive barrier air filter, an inspection of the 1st stage compressor for evidence of Foreign Object Damage (FOD), corrosion and contamination must be carried out at intervals not to exceed 220 hours time in service.\n\n8. All life limited components must be replaced at the engine manufacturer’s published life limits per AD/ENG/7.\n\n9. Critical components, as identified in the latest revision of the Pratt and Whitney Service Bulletin that applies to the engine model, must be inspected at intervals specified by Pratt and Whitney Canada.\n\n10. Engine work-scope during engine shop visits must have regard to the recommendations of Pratt and Whitney Canada, including minimum modification standards for engine durability; and\n\n11. TBO of accessories must have regard to the recommendations of Pratt and Whitney Canada.\n\n12. The on-condition program must be reviewed and revised as required at periods not exceeding 2 years taking into consideration all major defects and defects that affect engine durability. Outcome of the review must be reported to CASA via CASA’s online Defect Reporting System (DRS) Portal or via Form 404 referring to AD/ENG/5.","sortOrder":0},{"sectionNumber":"AD/ENG/5 Amdt 10","sectionType":"part","heading":"AD/ENG/5 Amdt 10","content":"## AD/ENG/5 Amdt 10","sortOrder":1},{"sectionNumber":"Turbine Engine Continuing Airworthiness ","sectionType":"part","heading":"Turbine Engine Continuing Airworthiness Requirements","content":"## Turbine Engine Continuing Airworthiness Requirements","sortOrder":2},{"sectionNumber":"6/2026","sectionType":"part","heading":"6/2026","content":"## 6/2026","sortOrder":3},{"sectionNumber":"PT6A Enhanced Maintenance Program","sectionType":"part","heading":"PT6A Enhanced Maintenance Program","content":"## PT6A Enhanced Maintenance Program","sortOrder":5},{"sectionNumber":"Appendix A","sectionType":"part","heading":"Appendix A","content":"## Appendix A","sortOrder":6},{"sectionNumber":"PT6A Agricultural OperationsOn-Condition","sectionType":"part","heading":"PT6A Agricultural OperationsOn-Condition Maintenance Program","content":"## PT6A Agricultural Operations  \nOn-Condition Maintenance Program","sortOrder":8},{"sectionNumber":"Appendix B","sectionType":"part","heading":"Appendix B","content":"## Appendix B","sortOrder":9}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This amendment is a technical update only — replacing an obsolete document reference with a current one. The scope remains consistent with the original intent of AD/ENG/5, which has always been to mandate turbine engine overhaul/inspection intervals. The directive continues to address the same engine types and operational categories as previous versions."},"complexity_factors":["Multiple overlapping compliance pathways (manufacturer's recommendations vs. directive-specific requirements vs. approved systems of maintenance)","Engine-specific carve-outs with different rules for Honeywell TPE331 vs. Pratt & Whitney PT6A series","Further bifurcation of PT6A rules based on aircraft operation type (aerial agricultural/fire-fighting vs. other operations)","Two detailed appendices (A and B) with 13 and 12 specific maintenance requirements respectively, including nested conditional requirements (e.g., hot section inspections at 1,250 hours OR 1,760 hours with boroscope inspections)","Cross-references to external documents: Civil Aviation Regulations 1988 (reg 42M), Civil Aviation Safety Regulations (CASR regs 21.189 and 21.195A), other ADs (AD/ENG/7), and specific manufacturer service bulletins","Defined technical terms requiring aviation expertise (TBO, ECTM, CAM, hot section inspection, boroscope inspection, life-limited components)","Temporal conditions (annual utilisation thresholds, calendar month limits, hours-in-service counting)","Grandfathering clause for previously approved Alternative Means of Compliance (AMOCs) from Amendment 9"],"plain_english_summary":"This AD mandates maximum time limits for turbine-engine overhauls and inspections on Australian-registered aircraft (excluding sports, limited-category and experimental aircraft) to prevent loss of power, uncontained failures, or debris damage. It allows compliance by following the engine maker’s schedule, using the AD’s specified schedules, or a CASA‑approved custom system; it includes specific compliance paths for Honeywell TPE331 and Pratt & Whitney PT6A engines (including an on‑condition option for agricultural/firebombing use). Amendment 10 updates a Pratt & Whitney reference document."},"flash_summary":{"complexity_score":7,"scope_assessment":{"changed":false,"description":"Amendment 10 updates references (replacing an obsolete Pratt & Whitney SIL citation with Revision 10) and sets out CASA-initiated maintenance options and enforcement details, but does not expand the AD's applicability beyond the previously excluded aircraft types. The instrument retains the substantive engine overhaul/inspection requirements while clarifying supporting service information (Background)."},"complexity_factors":["Multiple compliance pathways: manufacturer TBO, approved system of maintenance, or CASA-prescribed intervals (Requirement 1.1).","Engine-specific rules: special regimes for Honeywell TPE331 (Requirement 1.2) and PT6A series with separate enhanced (Appendix A) and on-condition agricultural programs (Appendix B) (Requirements 1.3–1.4).","Operational carve-outs and conditionality: different rules for aerial agricultural or fire-fighting operations (Requirement 1.3–1.4).","Mandatory engine condition trend monitoring (ECTM) with specified systems (WebECTM or CAMP) and training requirements (Appendix A ¶2; Appendix B ¶1).","Detailed inspection intervals and tasks (hot-section, fuel nozzles, oil filter, chip detector, FOD checks) creating frequent scheduled work (Appendices A & B).","Reporting and program-review obligations (biennial review and CASA Defect Reporting System/Form 404) impose administrative burden (Appendices A & B ¶13/12).","Dependence on external documents and revisions (manufacturer service bulletins, Pratt & Whitney SIL No. GEN-055 R10) introduces update and interpretation risk (Requirement 1.2; Background).","Retention of previously issued AMOCs/exclusions for prior amendment creates interaction with legacy approvals (Requirement text).","Applicability exclusions (sports aviation, limited category, experimental certificates) require operators to determine whether AD applies (Applicability).","Compliance timetable and effective dates create short lead-times for some operators (Compliance: effective 31 March 2026; compliance no later than 30 June 2026)."],"plain_english_summary":"This directive requires most turbine engines to be overhauled or inspected at specified intervals — by following manufacturer TBOs, an approved maintenance system, or CASA-specified schedules for Honeywell TPE331 and Pratt & Whitney PT6A engines. It targets aircraft operators and maintenance organisations who must carry out additional inspections, engine-condition monitoring (ECTM), component replacements and two-year program reviews. The stated purpose is to reduce risks like loss of power or uncontained engine debris by enforcing maintenance and reporting standards (Background; Requirements 1.1–1.4; Appendices A–B)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements","history":"/api/acts/ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements/history","analysis":"/api/acts/ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements/analysis","conflicts":"/api/acts/ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements/conflicts","importantCases":"/api/acts/ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements/important-cases","documents":"/api/acts/ad-eng-5-amdt-10-turbine-engine-continuing-airworthiness-requirements/documents"}}