{"id":"F2006B07260","name":"AD/T5508D/3 - 1st Stage Turbine Disk","slug":"ad-t5508d-3-1st-stage-turbine-disk","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49169,"registerId":"commonwealth-F2006B07260-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 CASR 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\nHoneywell International Turbine Engines \\- T5508D Series","sortOrder":0},{"sectionNumber":"AD/T5508D/3 1st Stage Turbine Disk 7/200","sectionType":"part","heading":"AD/T5508D/3 1st Stage Turbine Disk 7/2003","content":"# AD/T5508D/3 1st Stage Turbine Disk 7/2003\n\nApplicability: Honeywell T5508D engines fitted with first stage turbine disk part number (P/N) 2- 120-030-43.\n\nRequirement: Unless previously accomplished:\n\n    Carry out a visual and fluorescent penetrant inspection of the first turbine rotor assembly, P/N 2-120- 030-43, in accordance with the Accomplishment Instructions contained in Avco Lycoming Service Bulletin (SB) 5508-0031, Revision 1.\n    Remove and replace with new parts, bolts P/N 2-100-079-05 and their associated locking plates P/N 2-100-078-01, in accordance with the Accomplishment Instructions contained in Avco Lycoming SB 5508-0031, Revision 1.\n    Remove from service and replace with a serviceable part, all first turbine disks that exhibit fretting on the disk to shaft mating face and/or a crack indication during inspection.\n\nNote: FAA AD 86-19-13 Amdt. 39-5374 refers.\n\nCompliance: 1. Within the next 50 hours time in service after the effective date of this Directive.\n\n    2. When accomplishing the inspections of Requirement 1 of this Directive.\n\n    3. Prior to further flight.\n\nThis Airworthiness Directive becomes effective on 10 July 2003.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive applies specifically to T5508D engines with first-stage disk P/N 2-120-030-43 and prescribes inspections, part replacements and removals as set out. The text includes a reference to FAA AD 86-19-13 but does not indicate any expansion or narrowing of scope beyond those stated requirements."},"complexity_factors":["Narrow applicability — single engine model and specific part number (Applicability).","Technical inspection method required (visual and fluorescent penetrant) — requires qualified personnel and facilities (Requirement 1).","Mandatory parts replacement (bolts P/N 2-100-079-05 and locking plates P/N 2-100-078-01) following a manufacturer's service bulletin (Requirement 2).","Immediate operational impact for defective parts — disks with fretting/cracks must be removed prior to further flight (Requirement 3; Compliance 3).","Short compliance window for inspections (within 50 hours TIS) creates scheduling and logistic pressure (Compliance 1).","Dependency on Avco Lycoming SB 5508-0031 Revision 1 for accomplishment instructions — limits interpretation flexibility (Requirement).","Cross-reference to an FAA AD (Note) may require coordination for international operators."],"plain_english_summary":"Mechanically, this Airworthiness Directive requires operators of Honeywell T5508D engines fitted with first-stage turbine disk P/N 2-120-030-43 to perform a visual and fluorescent‑penetrant inspection, replace specified bolts and locking plates, and remove any disk showing fretting or crack indications. The work must follow Avco Lycoming Service Bulletin 5508-0031 Revision 1 and be done within 50 hours time‑in‑service (inspections) or before further flight (removals). The AD is issued by CASA under CASR subregulation 39.1(1)."},"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":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific safety defect in a specific engine part. It has not expanded beyond its original purpose of addressing unsafe turbine disk conditions."},"complexity_factors":["Single, clearly defined applicability (one engine model, one part number)","Three straightforward requirements with no nested conditions or exceptions","Simple compliance timeline (50 hours, at time of inspection, prior to flight)","Only one cross-reference (to FAA AD and Honeywell service bulletin)","No defined terms section — technical terms are explicit part numbers or standard aviation terminology","Total length is approximately 300 words"],"plain_english_summary":"This AD requires owners/operators of aircraft with Honeywell T5508D engines (first-stage turbine disk p/n 2-120-030-43) to inspect the turbine rotor (visual and fluorescent penetrant), replace specified bolts and locking plates, and remove from service any disks showing fretting or cracks. It matters because disk failure can cause catastrophic engine loss. Inspections are required within 50 flight hours of the AD (effective 10 July 2003); cracked/worn parts must be replaced before flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-t5508d-3-1st-stage-turbine-disk","history":"/api/acts/ad-t5508d-3-1st-stage-turbine-disk/history","analysis":"/api/acts/ad-t5508d-3-1st-stage-turbine-disk/analysis","conflicts":"/api/acts/ad-t5508d-3-1st-stage-turbine-disk/conflicts","importantCases":"/api/acts/ad-t5508d-3-1st-stage-turbine-disk/important-cases","documents":"/api/acts/ad-t5508d-3-1st-stage-turbine-disk/documents"}}