{"id":"F2006B07259","name":"AD/T5508D/2 - Compressor Bleed Bands","slug":"ad-t5508d-2-compressor-bleed-bands","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49165,"registerId":"commonwealth-F2006B07259-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\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/2 Compressor Bleed Bands 7/200","sectionType":"part","heading":"AD/T5508D/2 Compressor Bleed Bands 7/2003","content":"# AD/T5508D/2 Compressor Bleed Bands 7/2003\n\nApplicability: Honeywell (Avco Lycoming) T5508D engines fitted with Part Number (P/N) 2-160- 147-02 retaining plate spacers and P/N 2-161-182-01 compressor air bleed bands.\n\nRequirement: Replace P/N 2-160-147-02 retaining plate spacers with P/N 2-160-561-01 retainers in accordance with Avco Lycoming Service Bulletin (S/B) 5508-0007, and\n\nReplace P/N 2-161-182-01 compressor air bleed bands with P/N 2-161-182-03 compressor air bleed bands in accordance with Avco Lycoming S/B 5508-0007.\n\nNote: FAA AD 76-12-05 refers.\n\nCompliance: Prior to issue of an Australian certificate of airworthiness.\n\nThis Airworthiness Directive becomes effective on 10 July 2003.\n\nBackground: Failure of the bleed band can lead to power loss from the engine. Replacement of certain parts will allow proper operation of the bleed band system.\n\n![Signature of Jim Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 26 May 2003\n\n![](image.001.png)","sortOrder":1}],"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":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in specific engine models through prescribed part replacements. There is no evidence of scope creep."},"complexity_factors":["Very short document (under 300 words)","Only 2 specific part replacements required","Single compliance trigger (prior to certificate of airworthiness)","No defined terms section","No cross-references to other legislation (only references a service bulletin and FAA AD for information)","No conditional logic or exceptions","Straightforward applicability test (specific engine model + specific part numbers)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires replacement of two specific parts on Honeywell T5508D engines—old retaining plate spacers (2-160-147-02) and old compressor air bleed bands (2-161-182-01) with their updated counterparts—to eliminate a known bleed-band failure mode that can cause engine power loss. It affects owners, operators, and maintainers of these engines and must be done before Australian airworthiness certification."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope aligns with its stated safety purpose: it targets T5508D engines fitted with the listed part numbers and requires specified replacements before Australian certification. There is no expansion beyond replacing those parts per Avco Lycoming S/B 5508-0007 to address bleed-band failure (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Narrow technical applicability: applies only to T5508D engines fitted with the specified P/Ns (Applicability).","Prescriptive mandatory part-for-part replacements with exact P/Ns, limiting operator flexibility (Requirement).","Procedural reliance on an external service bulletin (Avco Lycoming S/B 5508-0007) for installation instructions (Requirement).","Compliance timing tied to issuance of an Australian certificate of airworthiness, affecting operators seeking certification (Compliance).","Regulatory basis uses delegated AD power under CASR 1998 subreg 39.1(1), creating administrative enforceability (first paragraph).","Safety rationale is specific and technical: the bleed-band failure risk (Background).","Practical implementation issues for operators include parts availability, procurement and labour costs (implicit from Requirement and Compliance).","Cross-reference to FAA AD 76-12-05 introduces inter-jurisdictional linkage to prior regulatory action (Note).","Specified effective date and mandatory compliance deadline create a clear but non-negotiable implementation timeline (Compliance; effective date)."],"plain_english_summary":"This Airworthiness Directive mandates replacement of specific parts on Honeywell (Avco Lycoming) T5508D engines: replace retaining plate spacers P/N 2-160-147-02 with P/N 2-160-561-01 and bleed bands P/N 2-161-182-01 with P/N 2-161-182-03, following Avco Lycoming S/B 5508-0007 (Applicability; Requirement). CASA’s delegate issues the AD under CASR 1998 subreg 39.1(1); operators must bear the cost and comply before an Australian certificate of airworthiness is issued because bleed-band failure can cause engine power loss (first paragraph; Compliance; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-t5508d-2-compressor-bleed-bands","history":"/api/acts/ad-t5508d-2-compressor-bleed-bands/history","analysis":"/api/acts/ad-t5508d-2-compressor-bleed-bands/analysis","conflicts":"/api/acts/ad-t5508d-2-compressor-bleed-bands/conflicts","importantCases":"/api/acts/ad-t5508d-2-compressor-bleed-bands/important-cases","documents":"/api/acts/ad-t5508d-2-compressor-bleed-bands/documents"}}