{"id":"F2006B06566","name":"AD/RB211/6 Amdt 4 - Low Pressure Compressor Rotor (Fan) Axial Retention","slug":"ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48324,"registerId":"commonwealth-F2006B06566-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/RB211/6 Amdt 4 - Low Pressure Compressor Rotor (Fan) Axial Retention","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Rolls Royce Turbine Engines - RB211 Series\n\n \n\nAD/RB211/6\n\nAmdt 4\n\n\nLow Pressure Compressor Rotor (Fan) Axial Retention\n\n\n9/87\n\n \n\nApplicability: RB211-524 series engines and modules as listed in Rolls Royce SB RB211-72-6576 R7.\n\n \n\nRequirement: Rolls Royce SB RB211-72-6576 Rev 7.\n\n \n\nNote: FAA AD 82-12-05 Amdt 39-4398 refers.\n\n \n\nCompliance: In accordance with the Requirement Document.\n\n \n\nBackground: This Directive has been amended to reflect the manufacturers latest revision to the Requirement Document. This revision amends the engine models and modules effectivity listing.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original purpose: ensuring axial retention of the low pressure compressor rotor in RB211 engines. Amendment 4 simply updates the affected engine models and modules list to match the manufacturer's latest service bulletin revision. There is no scope creep — the directive continues to address the same safety issue (fan rotor retention) on the same engine family."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 substantive sections: Applicability, Requirement, Note, and Compliance","Single cross-reference to FAA AD 82-12-05 (informational only)","No defined terms section — relies entirely on external Rolls-Royce service bulletin","No conditional logic or nested exceptions — compliance is straightforward 'follow the service bulletin'","Technical content is delegated to external manufacturer document (SB RB211-72-6576 R7)"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance or inspection actions on aircraft engines.\n\n**What it does:**\n- Requires owners and operators of certain **Rolls-Royce RB211-524 jet engines** to follow a specific Rolls-Royce service bulletin (SB RB211-72-6576 Revision 7).\n- The service bulletin deals with **\"Low Pressure Compressor Rotor (Fan) Axial Retention\"** — essentially, making sure the big front fan of the engine stays properly secured and doesn't shift forward or backward during flight.\n\n**Who it affects:**\n- Airlines and aircraft operators using RB211-524 series engines (commonly found on older Boeing 747s and Lockheed L-1011s).\n- Maintenance organisations servicing these engines.\n\n**Why it matters:**\n- Fan blade or rotor failures can cause catastrophic engine damage, potentially leading to loss of aircraft control. This directive ensures a known design weakness is addressed before it causes an accident.\n- **Compliance is mandatory** — operators cannot legally fly these engines without following the specified inspection or modification requirements.\n\n**Key details:**\n- This is **Amendment 4** (the fourth update to this directive), reflecting the manufacturer's latest revision to the service bulletin.\n- The amendment updates which specific engine models and modules are affected.\n- Operators must comply according to the timelines and procedures in the Rolls-Royce service bulletin itself."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment updates the Directive to reflect the manufacturer's latest revision of the Requirement Document; that revision amends the engine models and modules included in the effectivity listing, thereby changing which specific engines/modules the AD captures. (Background; Applicability)"},"complexity_factors":["The AD mandates compliance by reference to an external Requirement Document (Rolls-Royce SB RB211-72-6576 Rev 7), so the AD’s substantive technical detail is not in the AD itself (Requirement; Compliance).","Applicability is limited to specific engine models/modules listed in the Service Bulletin; determining whether an engine is captured requires consulting that Service Bulletin (Applicability; Background).","The AD does not set out timing, specific tasks, or enforcement details — those are handled in the Requirement Document or other regulatory material (Requirement; Compliance).","The amendment updates effectivity listings (which engines/modules are affected), creating potential need to re-check fleet applicability each time the Requirement Document is revised (Background).","There is a cross-reference to an FAA AD, introducing an additional external document for comparative review (Note)."],"plain_english_summary":"This AD makes compliance with Rolls‑Royce Service Bulletin RB211‑72‑6576, Revision 7 mandatory for specified RB211‑524 engines and listed modules, requiring operators to follow the manufacturer’s procedures addressing low‑pressure compressor (fan) axial retention. It updates effectivity to reflect the SB’s latest revision. Affected owners/operators must arrange and pay for the inspections, repairs or modifications the SB prescribes; the AD enforces the SB by reference and cites a related FAA AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention","history":"/api/acts/ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention/history","analysis":"/api/acts/ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention/analysis","conflicts":"/api/acts/ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention/conflicts","importantCases":"/api/acts/ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention/important-cases","documents":"/api/acts/ad-rb211-6-amdt-4-low-pressure-compressor-rotor-fan-axial-retention/documents"}}