{"id":"F2006B06562","name":"AD/RB211/31 - Engine Mount Bush - Replacement","slug":"ad-rb211-31-engine-mount-bush-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48310,"registerId":"commonwealth-F2006B06562-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\n![](image.001.png)  \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 CAR 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\nRolls Royce Turbine Engines \\- RB211 Series","sortOrder":0},{"sectionNumber":"AD/RB211/31 Engine Mount Bush - Replacem","sectionType":"part","heading":"AD/RB211/31 Engine Mount Bush - Replacement 6/2002","content":"# AD/RB211/31 Engine Mount Bush \\- Replacement 6/2002\n\nApplicability: Rolls Royce RB211 Series engines as listed in the Requirement document. Requirement: Action per Rolls Royce SB RB.211-71-D437.\n\nNote: The Requirement document has been classified as mandatory by UK-CAA.\n\nCompliance: As detailed in the Requirement document with a revised effective date of 13 June 2002.\n\nThis Airworthiness Directive becomes effective on 13 June 2002.\n\nBackground: Engine thrust loads are transmitted to the aircraft through the front mount support link, which contains a spherical bush. Cracking of this bush can compromise the thrust load path which can compromise aircraft safety. This directive mandates the replacement of these bushes.\n\n![Signature of James Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 1 May 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 22 May 2002.","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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD does not change the corrective action or the range of affected engines; it mandates replacement per the referenced service bulletin. The only procedural alteration in the text is a revised effective date (13 June 2002). No expansion or narrowing of scope is stated in the supplied document."},"complexity_factors":["External normative reference: compliance is through Rolls‑Royce SB RB.211‑71‑D437 (classified mandatory by UK‑CAA), creating a dependency on that document for technical detail and timing.","Technical maintenance task: replacing a spherical engine mount bush is an engineering procedure needing specialised parts, tooling and qualified personnel.","Applicability tracking: the AD applies to specific RB211 engine models, requiring accurate fleet identification and record checks.","Scheduling and operational impact: the AD sets an effective date (13 June 2002) and compliance timeline that operators must integrate into maintenance schedules.","Regulatory force: issued under CAR 1998 subregulation 39.1(1) by a CASA delegate, converting the requirement into a legal obligation with enforcement risk for non‑compliance."],"plain_english_summary":"**Mandates replacement of the spherical front-mount engine bushes on specified Rolls‑Royce RB211 engines by requiring compliance with Rolls‑Royce Service Bulletin RB.211‑71‑D437 (classified mandatory by UK‑CAA).** CASA issued this Airworthiness Directive effective 13 June 2002 and requires operators and maintenance organisations to carry out the replacement per the Requirement document. The AD responds to reported cracking that can break the thrust load path; operators pay and must schedule the maintenance to meet the compliance timing and regulatory obligation."},"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 a specific engine family. It does not expand beyond the original safety issue of cracked engine mount bushes."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly referenced (the 'Requirement document' = Rolls-Royce SB RB.211-71-D437)","No nested conditional logic or exceptions","Single, unambiguous compliance pathway: follow the external service bulletin","No cross-references to other legislation beyond subregulation 39.1(1) of CAR 1998 (cited once as enabling power)","Clear applicability limited to specific engine series"],"plain_english_summary":"This CASA Airworthiness Directive mandates replacement of the front mount spherical bearing (engine mount bush) on certain Rolls‑Royce RB211 engines after cracks were found. Operators of aircraft fitted with these RB211 engines must comply with Rolls‑Royce Service Bulletin RB.211‑71‑D437 (adopted as mandatory by the UK CAA). The AD took effect 13 June 2002."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-31-engine-mount-bush-replacement","history":"/api/acts/ad-rb211-31-engine-mount-bush-replacement/history","analysis":"/api/acts/ad-rb211-31-engine-mount-bush-replacement/analysis","conflicts":"/api/acts/ad-rb211-31-engine-mount-bush-replacement/conflicts","importantCases":"/api/acts/ad-rb211-31-engine-mount-bush-replacement/important-cases","documents":"/api/acts/ad-rb211-31-engine-mount-bush-replacement/documents"}}