{"id":"F2009L03432","name":"AD/T53/23 - Combustion Chamber Housings","slug":"ad-t53-23-combustion-chamber-housings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":141038,"registerId":"commonwealth-F2009L03432-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AlliedSignal (Lycoming) Turbine Engines ","sectionType":"division","heading":"AlliedSignal (Lycoming) Turbine Engines - T53 Series","content":"### AlliedSignal (Lycoming) Turbine Engines - T53 Series\n\n| AD/T53/23 | Combustion Chamber Housings | 10/2009 |\n| --------- | --------------------------- | ------- |\n\n| Applicability: | Honeywell International Inc. T5313B, T5317A, T5317A-1, T5317B, and T5317BCV turboshaft engines with combustion chamber housing (CCH), part numbers (P/Ns)1-130-610-05, 1-130-610-12, and 1-130-610-17, installed.Note 1: These engines are installed on, but not limited to, Bell 205 and 210 Series and Kaman K-1200 helicopters.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. For CCH, P/N 1-130-610-05 and 1-130-610-12, inspect the area between points A and B around the entire housing circumference in Figure 1 of this AD for weld repairs and cracks.2. If as a result of the Requirement 1 inspection:a. Any cracks are found - replace the CCH.b. If any weld repairs are found - replace the CCH.Honeywell International Inc. Alert Service Bulletin (ASB) T53-A0142,Revision 1, dated 14 September 2006, contains additional guidance on replacing the CCH.3. For CCH, P/N 1-130-610-05 and 1-130-610-12, inspect the area between points A and B around the entire housing circumference in Figure 1 of this AD for cracks.Honeywell International Inc. Standard Practices Manual 70-20-02, SP 1302, contains additional guidance on visual inspection.4. If you find any cracks, replace the CCH.Honeywell International Inc. ASB T53-A0142, Revision 1, contains additional guidance on replacing the CCH. |\n\n|             | Figure 1. Visual Inspection of CCH5. Perform an ultrasonic inspection on the CCH. Use Honeywell International Inc. Service Bulletin (SB) No. T53-0144, Revision 4, dated 31 March 2008, section 3. Accomplishment Instructions and the SB Appendix to perform the ultrasonic inspection.6. Repeat the ultrasonic inspection on the CCH using Honeywell International Inc. SB No. T53-0144, Revision 4, section 3. Accomplishment Instructions and the SB Appendix.Optional Terminating ActionInstallation of a CCH P/N 1-130-610-19 or 1-130-610R16, or an FAA approved equivalent part, terminates the inspection requirements of this AD.Note 2: FAA AD 2009-15-13 Amdt 39-15976 dated 14 July 2009 refers. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | For Requirement 1 - Within 50 hours time-in-service (TIS) after the effective date of this AD.For Requirement 2.a. - Before further flight.For Requirement 2.b. - Within 100 hours TIS after the visual inspection.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n\n|             | For Requirement 3 - Within every 50 hours time-since-last inspection.For Requirement 4 - Before further flight.For Requirement 5:For CCH, P/N 1-130-610-05 and 1-130-610-12, within 500 hours TIS or next hot section inspection, whichever occurs first after the effective date of this AD, but not to exceed 6 months after the effective date of this AD.For CCH, P/N 1-130-610-17, perform at the first overhaul, but do not exceed 5,000 hours or 11,000 cycles, after the effective date of this AD, whichever occurs first.For Requirement 6:Within every 1,200 flights, defined as the cumulative number of landings, since the last inspection; orWithin every 200 flights, if the last inspection had ultrasonic findings as defined in paragraph 3.A.(2) or paragraph 3.A.(3) of Honeywell International Inc. SBNo. T53-0144, Revision 4. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Airworthiness Directive becomes effective on 24 September 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Background: | This AD results from eight instances of cracks in CCHs. Two of the instances resulted in an engine shutdown during flight. The issuing of this AD is intended to detect cracks in the CCH, which could result in rupture of the CCH, leading to loss of engine power and damage to the helicopter.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n\n![](image.003.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n12 August 2009","sortOrder":0},{"sectionNumber":"AD/T53/23","sectionType":"part","heading":"AD/T53/23","content":"## AD/T53/23","sortOrder":1},{"sectionNumber":"Combustion Chamber Housings","sectionType":"part","heading":"Combustion Chamber Housings","content":"## Combustion Chamber Housings","sortOrder":2},{"sectionNumber":"10/2009","sectionType":"part","heading":"10/2009","content":"## 10/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in specific engine models. The document follows standard aviation safety regulatory format and does not appear to have expanded beyond its original safety purpose."},"complexity_factors":["Multiple part numbers (3) and engine models (5) with different inspection requirements","Nested conditional logic: different compliance timelines based on part number, inspection findings, and time-in-service vs. flight cycles","Cross-references to 4 external documents (Honeywell Service Bulletins and Standard Practices Manual)","Dual inspection methods required (visual AND ultrasonic) with different repeat intervals","Terminating action creates an alternative compliance path","Mixed units of measurement: hours time-in-service (TIS), flight cycles/landings, calendar months, and overhaul intervals"],"plain_english_summary":"This AD requires operators of certain Honeywell T53 turboshaft engines (T5313B, T5317 variants) fitted with combustion chamber housings p/n 1-130-610-05/12/17 to perform visual and ultrasonic inspections and replace any cracked or improperly welded housings before flight. Recurrent inspections are mandated until the housing is replaced.\n\nInstalling the improved CCH (p/n 1-130-610-19 or 1-130-610R16) terminates the inspection requirements. Non‑compliance risks catastrophic in‑flight engine failure."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The AD's measures (recurring inspections, mandatory replacement on defect, and an optional terminating action) directly implement the stated purpose of detecting and removing cracked CCHs after reported failures (Background). It does not broaden applicability beyond the listed engine types and P/Ns, though it permits terminating compliance by installing specified alternate parts (Optional Terminating Action)."},"complexity_factors":["Multiple affected part numbers and engine models (Applicability).","Two inspection modalities (visual and ultrasonic) with different procedures and thresholds (Requirements 1, 3, 5).","Different compliance triggers and intervals (hours TIS, flights/landings, overhaul limits, and conditional repeat intervals) increase scheduling complexity (Compliance).","Mandatory replacement on detection of cracks or weld repairs, plus an optional terminating action by fitting alternate P/Ns (Requirement 2; Optional Terminating Action).","Dependency on external Honeywell service documents (ASB T53-A0142; SB T53-0144) for inspection technique and acceptance criteria (Requirements 1–6).","Safety provenance and conditional escalation: issued after eight crack instances, two in-flight shutdowns, which justify recurring surveillance (Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of Honeywell T53 turboshaft engines fitted with specific combustion chamber housings (P/Ns 1-130-610-05, -12, -17) to carry out recurring visual and ultrasonic inspections and to replace any housing found with cracks or weld repairs. An optional terminating action allows fitment of new housings (P/N 1-130-610-19 or 1-130-610R16) to stop the inspections. The directive aims to detect and remove cracked housings after reported failures (Requirements 1–6; Background; Optional Terminating Action). Operators bear inspection, replacement and downtime costs; CASA mandates timing and intervals (Compliance)."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-t53-23-combustion-chamber-housings","history":"/api/acts/ad-t53-23-combustion-chamber-housings/history","analysis":"/api/acts/ad-t53-23-combustion-chamber-housings/analysis","conflicts":"/api/acts/ad-t53-23-combustion-chamber-housings/conflicts","importantCases":"/api/acts/ad-t53-23-combustion-chamber-housings/important-cases","documents":"/api/acts/ad-t53-23-combustion-chamber-housings/documents"}}