{"id":"F2006B11387","name":"AD/MU-2/57 - Acrylic Windshield and Side Windows","slug":"ad-mu-2-57-acrylic-windshield-and-side-windows","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57288,"registerId":"commonwealth-F2006B11387-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MU-2/57 - Acrylic Windshield and Side Windows","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nMitsubishi MU-2 Series Aeroplanes\n\nAD/MU-2/57 Acrylic Windshield and Side Windows 6/96\n\nApplicability: MU-2B \\-10, \\-15, \\- 20, \\-25, \\-26 S/N 008 to 347 (except 313 and 321), and \\-30, \\-35, \\-\n\n36, S/N 501 to 696 (except 652 and 661); equipped with windscreen, cockpit or cabin windows P/Nos:\n\n010A-31450-1 or \\-2 010A-31451-1 or \\-2\n\n010A-31874-1 or \\-2 010A-31870\n\n010A-31870-11 030A-32402\n\nRequirement: Inspect, and replace as necessary, in accordance with MHI MU-2 SB 224A.\n\nNote: JCAB AD TCD-4311-95 refers.\n\nCompliance: Within 100 hours time in service after 23 May 1996, thereafter at intervals not exceeding 100 hours time in service.\n\nBackground: This Directive is issued to prevent possible in-flight failure of the acrylic transparencies due to undetected cracking.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text, as provided, defines a narrowly targeted directive: it applies only to specified MU‑2 submodels, serial-number ranges (with stated exceptions) and particular window part numbers, and it prescribes inspection/replacement in accordance with the manufacturer’s service bulletin on a 100‑hour recurring basis (Applicability; Requirement; Compliance). There is no indication in the provided text that the AD’s scope was altered from its original stated purpose (to prevent in‑flight failure of acrylic transparencies) or that it extends beyond the technical measures and affected aircraft identified in the directive (Background)."},"complexity_factors":["Specific applicability by model, serial-number ranges and explicit exclusions increases administrative checking (Applicability).","Mandating compliance “in accordance with” an external manufacturer service bulletin means technical actions rely on another document (Requirement).","Recurring, short interval (every 100 hours) inspections create an ongoing operational and scheduling burden (Compliance).","Multiple part numbers are listed for affected transparencies, requiring parts-level verification (Applicability).","The AD text sets the safety action and timing but does not detail enforcement or alternative compliance paths within the text, leaving those procedural matters to the broader regulatory framework and the referenced service bulletin (Requirement; Compliance)."],"plain_english_summary":"This AD requires operators of specified Mitsubishi MU‑2 aeroplanes fitted with listed acrylic windscreens/cabin windows to inspect those transparencies per MHI MU‑2 SB 224A and replace them if required. The first inspection is within 100 hours TIS (after 23 May 1996) and then every 100 hours. It targets only aircraft with the named models/serials/part numbers, shifts recurring maintenance and replacement costs to operators, and aims to prevent in‑flight failure from cracking."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific known defect in a specific aircraft type. It has not expanded beyond its original purpose of preventing acrylic window failures."},"complexity_factors":["Single, specific maintenance task with clear applicability criteria","Only 7 part numbers and specific serial number ranges to check","Simple compliance timeline: initial inspection + recurring 100-hour intervals","No nested exceptions, conditional logic, or cross-references to other legislation","Background and rationale clearly stated in one sentence","Total length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Mitsubishi MU-2 aeroplanes** to inspect their acrylic (plastic) windshields and side windows for cracks, and replace any damaged ones. The inspections must follow a specific service bulletin from the manufacturer (Mitsubishi Heavy Industries).\n\n**Who it affects:**\n- Owners and operators of MU-2B model aircraft with specific serial numbers (roughly 1960s–1980s production)\n- Only applies to planes with particular window part numbers listed in the directive\n\n**Why it matters:**\nCracked acrylic windows can fail suddenly during flight, potentially causing rapid decompression, loss of visibility, or structural damage. This rule exists to catch cracks before they become catastrophic.\n\n**What must be done:**\n- First inspection: within 100 hours of flying time after 23 May 1996\n- Repeat inspections: every 100 hours of flying time thereafter\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A legally binding safety order that must be followed to keep an aircraft certified to fly\n- **Time in service:** Actual flying hours (not calendar time)\n- **Service Bulletin (SB):** Manufacturer's technical instructions for maintenance or repairs"}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-57-acrylic-windshield-and-side-windows","history":"/api/acts/ad-mu-2-57-acrylic-windshield-and-side-windows/history","analysis":"/api/acts/ad-mu-2-57-acrylic-windshield-and-side-windows/analysis","conflicts":"/api/acts/ad-mu-2-57-acrylic-windshield-and-side-windows/conflicts","importantCases":"/api/acts/ad-mu-2-57-acrylic-windshield-and-side-windows/important-cases","documents":"/api/acts/ad-mu-2-57-acrylic-windshield-and-side-windows/documents"}}