{"id":"F2006B09297","name":"AD/DO-27/2 - Tailplane Front Spar - Modification","slug":"ad-do-27-2-tailplane-front-spar-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53379,"registerId":"commonwealth-F2006B09297-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DO-27/2 - Tailplane Front Spar - Modification","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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Dornier DO-27 Series Aeroplanes\n\n \n\nAD/DO-27/2 Tailplane Front Spar - Modification 2/64\n\nApplicability: All DO27Q series prior to S/No. 2139.\n\n \n\nRequirement: 1. Modify the centre section of the front tailplane spar in accordance with Dornier Technical Bulletin No. 27/13 Rectification part “B” unless Part “A” has been carried out. or\n\n \n\n2. Dornier TB No. 27/13. Compliance: Before 1 September 1971.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2007},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope, applying only to specific aircraft serial numbers for a discrete structural safety modification."},"complexity_factors":["Extremely brief directive (under 100 words) with minimal procedural detail","Complete reliance on external technical specifications (Dornier Technical Bulletin 27/13) not reproduced in the text","Technical aviation terminology requiring specialist engineering knowledge","Simple conditional logic (Part B compliance required unless Part A previously completed)"],"plain_english_summary":"**What this is:** A mandatory safety instruction (called an Airworthiness Directive) issued by the Civil Aviation Safety Authority for specific German-made aircraft operating in Australia.\n\n**Who it affects:** Owners and operators of **Dornier DO27Q model aeroplanes** with serial numbers below 2139.\n\n**What you must do:** Modify the centre section of the front tailplane spar (the main structural beam in the rear horizontal stabilizer). You must follow the instructions in **Dornier Technical Bulletin No. 27/13**, specifically **Part B**—unless you have already completed Part A.\n\n**Why this matters:** This structural modification prevents potential failure of the tailplane, which could cause catastrophic loss of aircraft control.\n\n**Compliance deadline:** The modification had to be completed before **1 September 1971**."}},"importantCases":[],"_links":{"self":"/api/acts/ad-do-27-2-tailplane-front-spar-modification","history":"/api/acts/ad-do-27-2-tailplane-front-spar-modification/history","analysis":"/api/acts/ad-do-27-2-tailplane-front-spar-modification/analysis","conflicts":"/api/acts/ad-do-27-2-tailplane-front-spar-modification/conflicts","importantCases":"/api/acts/ad-do-27-2-tailplane-front-spar-modification/important-cases","documents":"/api/acts/ad-do-27-2-tailplane-front-spar-modification/documents"}}