{"id":"F2006B11010","name":"AD/JT9D/17 Amdt 2 - Fan Containment Shield","slug":"ad-jt9d-17-amdt-2-fan-containment-shield","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56610,"registerId":"commonwealth-F2006B11010-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JT9D/17 Amdt 2 - Fan Containment Shield","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPratt and Whitney Turbine Engines \\- JT9D Series\n\nAD/JT9D/17\n\nAmdt 2\n\n  \nFan Containment Shield 8/90\n\nApplicability: JT9D \\- 7R4D, D1, E, E1, E4, H1 series engines.\n\nRequirement: Install an improved fan containment shield in accordance with the requirements of PWA SB No JT9D - 7R4 - 72 - 312 Rev 6.\n\nNote 1: Compliance with the requirements of a previous revision of the Requirement document is considered as compliance with the Requirements of this Directive.\n\nNote 2: FAA AD 87-23-05 R1 refers.\n\nCompliance: At next scheduled engine shop visit, but no later than 31 December 1990.\n\nBackground: This amendment reflects advice that additional procedures are available which permit alternative methods of installing the improved fan containment shield. These alternative procedures are published in subsequent revisions to Requirement document PWA SB No JT9D-7R4-72-312. Rev 2.\n\nEngines already in compliance with the Requirements of CAO 106 AD/JT9D/17 Amdt 1 are considered to be in compliance with the Requirements of this Amendment.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of AD/JT9D/17. It does not expand applicability to new engine models or introduce new safety issues. The amendment's sole purpose is to incorporate alternative installation procedures and clarify that compliance with the previous version remains valid. This is a technical refinement within the original safety intent."},"complexity_factors":["Very short document (under 300 words)","Only 4 defined applicability criteria (specific engine model numbers)","Single primary requirement with clear reference to external technical document","Simple compliance deadline structure (next shop visit OR hard date)","Two straightforward grandfathering provisions (previous compliance counts, alternative methods permitted)","No nested conditional logic or cross-references to other legislation beyond a single FAA AD reference for context"],"plain_english_summary":"This CASA Airworthiness Directive mandates installation of an improved fan containment shield on certain Pratt & Whitney JT9D engines (affecting operators and maintenance organisations) to prevent debris from a fan-blade failure damaging the aircraft or harming occupants. \n\nCompliance follows Pratt & Whitney Service Bulletin JT9D-7R4-72-312 (Rev 6 or later), is due by the next engine overhaul but no later than 31 Dec 1990; prior Amendment 1 compliance remains acceptable and alternative methods in later revisions are permitted."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment does not alter the core requirement (install an improved fan containment shield) or the listed engine types, but it broadens acceptable installation methods by recognising additional procedures published in subsequent revisions of PWA SB No JT9D‑7R4‑72‑312 (Background). It also explicitly treats compliance with an earlier amendment as compliant with this amendment (Note 1), so the practical scope of acceptable compliance methods has expanded while the substantive obligation remains the same."},"complexity_factors":["Narrow technical scope: single retrofit action (install improved fan containment shield)","Limited applicability: specific JT9D sub‑series listed (clarity reduces complexity)","Compliance timing tied to operational maintenance schedule (next shop visit) plus a calendar backstop (31 Dec 1990)","Dependence on an external document (PWA SB No JT9D‑7R4‑72‑312 Rev 6) for procedural detail","Equivalence and change management: accepts earlier SB revisions and allows later revisions to provide alternative procedures (creates version‑control complexity)","Cross‑reference to FAA AD increases multi‑jurisdictional compliance considerations"],"plain_english_summary":"This airworthiness directive requires operators of Pratt & Whitney JT9D‑7R4D, D1, E, E1, E4 and H1 series engines to have an improved fan containment shield fitted in accordance with PWA Service Bulletin JT9D‑7R4‑72‑312 Rev 6. Compliance must occur at the next scheduled engine shop visit and no later than 31 December 1990. The amendment accepts earlier compliance under prior revisions and notes that later revisions may include alternative installation procedures, so engine owners pay for the retrofit and maintenance providers must follow the specified service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt9d-17-amdt-2-fan-containment-shield","history":"/api/acts/ad-jt9d-17-amdt-2-fan-containment-shield/history","analysis":"/api/acts/ad-jt9d-17-amdt-2-fan-containment-shield/analysis","conflicts":"/api/acts/ad-jt9d-17-amdt-2-fan-containment-shield/conflicts","importantCases":"/api/acts/ad-jt9d-17-amdt-2-fan-containment-shield/important-cases","documents":"/api/acts/ad-jt9d-17-amdt-2-fan-containment-shield/documents"}}