{"id":"F2006B08702","name":"AD/DART/16 - Combustion Chamber Air Casing","slug":"ad-dart-16-combustion-chamber-air-casing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51883,"registerId":"commonwealth-F2006B08702-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DART/16 - Combustion Chamber Air Casing","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/16 Combustion Chamber Air Casing 11/87\n\nApplicability: All Dart RDa-6, RDa-7 series engines.\n\n \n\nRequirement: 1. Action in accordance with Rolls Royce SB Da 72-A471; or\n\n \n\n2. AD/RRT/29.\n\n \n\nNote: CAA AD 002-02-82 and RLD BLA No. 82-12-72 refers.\n\n \n\nEffectivity: Forthwith.\n\n \n\nBackground: Reissue of AD/RRT/29.\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 targeting a specific technical issue in specific engine models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (under 200 words)","Only 2 defined applicability criteria (engine model series)","Simple binary compliance path (Option 1 OR Option 2)","No nested exceptions, conditional clauses, or cross-references to other legislation beyond a single alternative directive and a service bulletin","Single operational requirement with immediate effectivity","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/16) requires owners and operators of specific Rolls-Royce Dart engines (the RDa-6 and RDa-7 series) to take action regarding the **combustion chamber air casing** — a critical component that helps manage airflow and combustion in the engine.\n\n**Who must act:**\nAnyone operating aircraft with these specific Dart engine models.\n\n**What action is required:**\nOperators must either:\n- Follow **Rolls-Royce Service Bulletin Da 72-A471** (technical instructions from the manufacturer); OR\n- Comply with a previous directive called **AD/RRT/29**\n\n**Why it matters:**\nThis is a **reissue** of an earlier safety directive, meaning there was already a known issue with these engine casings that required fixing. The \"effectivity: forthwith\" means this must be done immediately — there's no grace period. Non-compliance could mean the aircraft is not legally airworthy and cannot fly.\n\n**In short:** If you fly or maintain an older aircraft with these Rolls-Royce Dart engines (common in regional airliners from the 1950s-70s like the Fokker F27 or Vickers Viscount), you must inspect or modify the combustion chamber casing right away per the manufacturer's instructions."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD is presented as a reissue of AD/RRT/29 (Background) and restates the same applicability (all Dart RDa‑6 and RDa‑7 engines) and the same two compliance options (Rolls‑Royce SB Da 72‑A471 or AD/RRT/29). The supplied text does not indicate any expansion or narrowing of the technical or regulatory scope compared with the prior AD; therefore there is no apparent change of scope in this reissue."},"complexity_factors":["Short, direct mandatory command but lacks technical detail — relies on external documents for the substantive work (Rolls‑Royce SB Da 72‑A471; AD/RRT/29). (Requirement; Note)","Immediate effectivity (‘Forthwith’) increases scheduling and operational urgency. (Effectivity)","Two alternative compliance pathways require operators to choose and justify the path they take. (Requirement)","Cross‑references to prior directives and bulletins create traceability requirements and a need to access historical documents. (Note; Background)","Applicability is precise (specific engine models), which reduces interpretive ambiguity but concentrates impact on a defined group. (Applicability)"],"plain_english_summary":"What this instrument does (mechanically)\n\n- This airworthiness directive (AD/DART/16) applies to all Rolls‑Royce Dart RDa‑6 and RDa‑7 series turbine engines. (Applicability)\n- It requires engine operators to carry out one of two compliance options: either follow Rolls‑Royce Service Bulletin Da 72‑A471, or comply with AD/RRT/29. (Requirement)\n- The requirement is effective immediately — operators must comply forthwith. (Effectivity)\n- The AD is a reissue of a prior directive (AD/RRT/29). (Background)\n- The document also cross‑references CAA AD 002‑02‑82 and RLD BLA No. 82‑12‑72. (Note)\n\nWho pays, who decides, and what behavior changes\n\n- Who pays: The owners/operators of aircraft fitted with Dart RDa‑6 or RDa‑7 engines are responsible for carrying out the mandated action and therefore will incur any direct costs (parts, labour, downtime) required by the chosen compliance option. (Applicability; Requirement)\n- Who decides: The Civil Aviation Safety Authority (via this AD) sets the mandatory requirement and provides the two alternative compliance paths; the operator decides which of the two specified options to follow. (Header; Requirement)\n- What changes in behaviour: Operators must obtain and implement either the Rolls‑Royce service bulletin Da 72‑A471 or the measures set out in AD/RRT/29 without delay. This changes maintenance planning and creates an immediate compliance obligation. (Requirement; Effectivity)\n\nPractical implications, trade‑offs and implementation considerations\n\n- Compliance pathways: The AD gives two explicit pathways (manufacturer service bulletin or an earlier AD). That creates operational choice but means operators must access and understand the external documents before acting. (Requirement)\n- Costs and downtime: The AD does not specify the work scope or cost; following the service bulletin or the referenced AD will involve maintenance labour, possible parts, and aircraft/engine downtime. Those are direct, concentrated costs on operators/owners. (Requirement)\n- Administrative and availability risk: Because the AD refers to external documents (Rolls‑Royce SB Da 72‑A471; AD/RRT/29; plus two additional cross‑references), compliance depends on obtaining those documents and interpreting them correctly. This raises a modest compliance burden and an implementation risk if documents are unavailable or ambiguous. (Requirement; Note)\n- Immediate effectivity: “Forthwith” means there is no transition period built into this AD; operators must prioritise compliance in maintenance scheduling. That increases near‑term disruption risk. (Effectivity)\n- Regulatory discretion and continuity: The AD is a reissue of a prior directive (AD/RRT/29). The regulator has chosen to continue or re‑impose the requirement; the text supplied does not indicate any expanded or narrowed technical scope, only that the requirement has been reissued. (Background)\n\nWhat the AD does not specify (gaps an operator will need to resolve)\n\n- The AD does not detail the specific inspection, repair or modification tasks, nor the time limits or intervals for compliance — those details must be read in the referenced Rolls‑Royce service bulletin or in AD/RRT/29. (Requirement; Note)\n- The AD does not state who pays for parts or how compliance is to be certified; operators must follow the usual maintenance certification processes under the civil aviation regulatory framework. (Requirement)\n\nBottom line\n\nThis AD legally obliges operators of Dart RDa‑6 and RDa‑7 engines to carry out either the specified Rolls‑Royce service bulletin or the measures in AD/RRT/29 immediately. The regulator provides two compliance pathways but leaves the technical specifics to the referenced documents. The immediate compliance date concentrates costs and operational disruption on engine owners/operators and requires them to obtain and follow the external documents cited. (Applicability; Requirement; Effectivity; Note; Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dart-16-combustion-chamber-air-casing","history":"/api/acts/ad-dart-16-combustion-chamber-air-casing/history","analysis":"/api/acts/ad-dart-16-combustion-chamber-air-casing/analysis","conflicts":"/api/acts/ad-dart-16-combustion-chamber-air-casing/conflicts","importantCases":"/api/acts/ad-dart-16-combustion-chamber-air-casing/important-cases","documents":"/api/acts/ad-dart-16-combustion-chamber-air-casing/documents"}}