{"id":"F2006B08707","name":"AD/DART/21 - Torque Pressure Indication","slug":"ad-dart-21-torque-pressure-indication","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51895,"registerId":"commonwealth-F2006B08707-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DART/21 - Torque Pressure Indication","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 - Dart Series\n\n \n\nAD/DART/21 Torque Pressure Indication 11/87\n\nApplicability: All Dart RDa-6, RDa-7 series engines incorporating Mod. 1867. Requirement:  1. Action in accordance with Rolls Royce SB Da 77-A12; or\n\n2. AD/RRT/37. Compliance: Forthwith.\n\nBackground: Reissue of AD/RRT/37.\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\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 standard, narrow airworthiness directive focused on a specific technical issue with specific engine models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (engine models and modification status)","Simple binary compliance path (follow SB or previous AD)","No nested conditions, exceptions, or cross-references to other legislation beyond the single reference to AD/RRT/37","Single operative requirement with immediate effect","No interpretation section or defined terms"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft engines.\n\n**What it does:**\nThis directive (AD/DART/21) requires immediate action on certain Rolls-Royce Dart turbine engines used in aircraft. Specifically, it applies to Dart RDa-6 and RDa-7 series engines that have been modified with \"Mod. 1867\" (a specific engine modification).\n\n**What must be done:**\nOperators must either:\n- Follow the instructions in Rolls-Royce Service Bulletin Da 77-A12 (official technical instructions from the manufacturer); OR\n- Comply with a previous directive called AD/RRT/37\n\n**When:** \"Forthwith\" — meaning immediately, without delay.\n\n**Why it matters:**\nThis directive was reissued to replace an earlier safety order (AD/RRT/37). Airworthiness Directives are legally binding — aircraft cannot fly legally if they don't comply. This likely addresses a safety issue with how torque pressure is indicated on these engines, which is critical for pilots to monitor engine performance and prevent damage or failure.\n\n**Who it affects:**\nAirlines, charter operators, or private owners operating aircraft with these specific Rolls-Royce Dart engines."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD states it is a reissue of AD/RRT/37 (Background). The applicability and requirements in the published text apply to the same set of engines (RDa-6 and RDa-7 with Mod. 1867) and require compliance with the same referenced service bulletin or the prior AD (Applicability; Requirement). Based on the instrument text, the scope of affected engines and required actions is continued rather than expanded or narrowed."},"complexity_factors":["Narrow technical applicability limited to RDa-6 and RDa-7 engines with Mod. 1867 (Applicability)","Mandates compliance with an externally referenced service bulletin or an alternative AD rather than prescribing technical steps in the text (Requirement)","Immediate compliance required (\"Forthwith\") increases operational scheduling complexity (Compliance)","Reissue of a previous AD creates a short traceability chain to AD/RRT/37 (Background)","Limited internal procedural detail in the AD; reliance on external technical documents adds dependency complexity"],"plain_english_summary":"This mandatory airworthiness directive applies to Rolls‑Royce Dart RDa‑6 and RDa‑7 engines with Mod.1867 and requires immediate compliance with Rolls‑Royce Service Bulletin Da 77‑A12 or the alternative AD/RRT/37 to address torque/pressure indication issues. Engine owners/operators bear the cost and scheduling burden; maintenance organisations or certifying engineers choose and carry out the specified corrective route."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dart-21-torque-pressure-indication","history":"/api/acts/ad-dart-21-torque-pressure-indication/history","analysis":"/api/acts/ad-dart-21-torque-pressure-indication/analysis","conflicts":"/api/acts/ad-dart-21-torque-pressure-indication/conflicts","importantCases":"/api/acts/ad-dart-21-torque-pressure-indication/important-cases","documents":"/api/acts/ad-dart-21-torque-pressure-indication/documents"}}