{"id":"F2006B06688","name":"AD/RRT-S/7 - Airflow Control Bleed Valve - Removal of Mod. 5866","slug":"ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48730,"registerId":"commonwealth-F2006B06688-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/RRT-S/7 - Airflow Control Bleed Valve - Removal of Mod. 5866","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 - Spey Series\n\n \n\nAD/RRT-S/7 Airflow Control Bleed Valve - Removal of Mod. 5866 11/83\n\nApplicability: 511-5W, 511-8, 511-14, 511-14W, 555-15/555-15H/555-15N/555/15P. Featuring Mod. 5866 (SB Sp 72-916).\n\n \n\nRequirement: Rolls Royce SB No. SP72-964 (Modification 6040).\n\n \n\nCompliance: Before installation in an aircraft following next shop visit after 30th November 1983.\n\n \n\nBackground: Compliance with this Directive will supersede AD/RRT-S/6 which has been raised to alert operators of the possibilities of power stagnation and excessive TGT excursions associated with engine accelerations from low power settings.\n\nIncorporation of modification 6040 should prevent these stagnations caused by bleed valve mechanism stiction.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific engine models. It remains focused on its original purpose of preventing power stagnation through hardware modification. No scope creep is evident."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined technical references (SB SP72-964 and Modification 6040)","Single, clear compliance requirement with one deadline","No nested exceptions or conditional logic","Straightforward applicability list (6 engine variants)","Minimal cross-referencing (only references predecessor AD/RRT-S/6 and one Service Bulletin)"],"plain_english_summary":"This CASA Airworthiness Directive mandates removal of Rolls‑Royce Spey engine modification Mod.5866 and replacement with Mod.6040 per Rolls‑Royce Service Bulletin SP72‑964 for affected 511 and 555 series engines that currently carry Mod.5866. It responds to incidents of low‑power stagnation and excessive TGT excursions that risk engine failure or loss of control. Compliance is required before installation or at the next shop visit after 30 Nov 1983; it supersedes the earlier warning."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive narrows to a specific mandated modification for listed engine models and replaces the earlier advisory AD/RRT‑S/6 with a required fix; it does not broaden applicability beyond the originally affected Spey variants listed in the instrument."},"complexity_factors":["Very narrow technical scope — applies only to specific Rolls‑Royce Spey variants listed (clear applicability).","Single, discrete mandated action — install SB SP72‑964 (Mod. 6040).","Fixed compliance trigger — ‘next shop visit after 30 Nov 1983’ creates a clear scheduling point but requires coordination with maintenance cycles.","Supersedes a prior directive (AD/RRT‑S/6) — introduces a change-management step for operators to note replacement of previous guidance.","Technical cause identified (bleed‑valve mechanism stiction) — requires shop‑level mechanical intervention rather than operational restrictions.","Document is short and prescriptive, reducing interpretive compliance burden."],"plain_english_summary":"This airworthiness directive requires specified Rolls‑Royce Spey engines fitted with Mod. 5866 to receive Rolls Royce Service Bulletin SP72‑964 (Modification 6040) at the next shop visit after 30 November 1983. It is intended to prevent power stagnation and excessive turbine gas temperature (TGT) excursions caused by bleed‑valve stiction. Operators and maintenance organisations must perform and pay for the modification before the engine is next installed; the directive supersedes AD/RRT‑S/6."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866","history":"/api/acts/ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866/history","analysis":"/api/acts/ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866/analysis","conflicts":"/api/acts/ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866/conflicts","importantCases":"/api/acts/ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866/important-cases","documents":"/api/acts/ad-rrt-s-7-airflow-control-bleed-valve-removal-of-mod-5866/documents"}}