{"id":"F2006B06567","name":"AD/RB211/7 - Low Pressure Compressor Rotor (Fan) Shafts Inspection","slug":"ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48327,"registerId":"commonwealth-F2006B06567-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/RB211/7 - Low Pressure Compressor Rotor (Fan) Shafts Inspection","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/RB211/7 Low Pressure Compressor Rotor (Fan) Shafts Inspection\n\n\n6/82\n\n \n\nApplicability: RB211-524B3-02, -524B4-02 and -524D4-19 engines and variants incorporating LP compressor rotor shaft/ shaft assemblies part numbers LK75179, LK75180, LK75181 or LK87852.\n\n \n\nDocument: Rolls Royce RB211 Alert Service Bulletin RB211-72-A6820, Rev. 1. Compliance:  In accordance with the requirement document.\n\nBackground: Inspection of a new L.P. compressor shaft at Rolls Royce revealed a circumferential crack in an outside radius of the stepped part of the shaft. The crack may be associated with a heat treatment process and this Directive is issued to require certain suspect shafts to be inspected.\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 Airworthiness Directive maintains its original narrow, targeted scope. It addresses a specific manufacturing defect in specific engine models with specific part numbers. There is no evidence of scope creep; the directive remains precisely focused on the identified safety issue with the LP compressor rotor shafts."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 4 specific part numbers to identify affected components","Single compliance pathway (follow the referenced service bulletin)","No defined terms section — all technical terms are standard aviation/engineering terminology","No conditional logic, exceptions, or nested provisions","Single background fact pattern with straightforward causal link (heat treatment → crack → inspection required)","Cross-reference to only one external technical document (the Rolls-Royce service bulletin)"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific inspections on certain aircraft engines.\n\n**What it does:**\n- Requires inspection of the **low-pressure compressor rotor (fan) shafts** on specific Rolls-Royce RB211 jet engines\n- Targets engines with particular shaft part numbers (LK75179, LK75180, LK75181, or LK87852)\n\n**Why it matters:**\n- Rolls-Royce discovered a **circumferential crack** (a crack running around the circumference of a part) in a new compressor shaft during manufacturing inspection\n- The crack appears linked to a **heat treatment process** (a manufacturing step that hardens metal)\n- This directive prevents potentially dangerous engine failures by catching defective shafts before they cause accidents\n\n**Who it affects:**\n- Operators of aircraft using RB211-524B3-02, -524B4-02, or -524D4-19 engines (and their variants)\n- Maintenance organisations servicing these engines\n\n**What must happen:**\n- Compliance follows Rolls-Royce Alert Service Bulletin RB211-72-A6820, Revision 1\n- This means mechanics must follow the manufacturer's specific inspection procedures exactly as written in that technical document"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive imposes inspection requirements on the specific engines and shaft part numbers identified; it does not expand or narrow scope beyond the listed applicability and the manufacturer’s requirement document. There is no indication in the text that the AD alters an earlier scope or departs from its stated purpose (Background: inspection revealed crack; Compliance: in accordance with the requirement document)."},"complexity_factors":["Narrow applicability: specific engine models and four shaft part numbers are listed (Applicability: RB211-524B3-02, -524B4-02 and -524D4-19; part numbers LK75179, LK75180, LK75181, LK87852).","Delegated compliance: the AD requires action “In accordance with the requirement document” (Document: Rolls Royce RB211 Alert Service Bulletin RB211-72-A6820, Rev. 1), so technical detail and procedures are in the manufacturer bulletin rather than the AD text.","Technical inspection requirement: inspections for a circumferential crack in an outside radius of a stepped shaft section imply use of appropriate non‑destructive inspection methods and qualified personnel (Background: inspection revealed circumferential crack).","Traceability and parts identification: compliance depends on accurately identifying affected shaft part numbers and engine variants, increasing administrative and logistical steps for operators.","Binary compliance outcome: AD prescribes inspection (and implicit follow‑on actions per the bulletin) rather than phased monitoring, reducing regulatory ambiguity but requiring immediate operational responses."],"plain_english_summary":"This Airworthiness Directive requires inspection of certain low‑pressure compressor (fan) shafts on specified Rolls‑Royce RB211‑524 engine models. Operators of engines with part numbers LK75179, LK75180, LK75181 or LK87852 must carry out inspections in accordance with Rolls‑Royce Alert Service Bulletin RB211‑72‑A6820 Rev.1 because a circumferential crack was found in a new shaft (possible heat‑treatment issue). The rule mechanically mandates inspection per the manufacturer document and applies only to the listed engines and shaft part numbers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection","history":"/api/acts/ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection/history","analysis":"/api/acts/ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection/analysis","conflicts":"/api/acts/ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection/conflicts","importantCases":"/api/acts/ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection/important-cases","documents":"/api/acts/ad-rb211-7-low-pressure-compressor-rotor-fan-shafts-inspection/documents"}}