{"id":"F2006B11361","name":"AD/MU-2/31 - Cockpit Airconditioning Ducts - Inspection and Modification","slug":"ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57260,"registerId":"commonwealth-F2006B11361-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MU-2/31 - Cockpit Airconditioning Ducts - Inspection and 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)  Mitsubishi MU-2 Series Aeroplanes\n\n \n\n# AD/MU-2/31 Cockpit Airconditioning Ducts - Inspection\n\nand Modification\n\nApplicability: All models MU-2B-26A/-40 with S/Nos. 321SA, 348SA, 350SA to 457SA.\n\n# 1/84\n\n \n\nMU-2B-36A/-60 with S/Nos. 661SA, 697SA to 699SA, 1501SA to 1542SA, 1544SA to 1547SA.\n\n \n\nDocument: Mitsubishi SB No. 040/21-002.\n\n \n\nCompliance: Prior to issue of the next maintenance release after 21 December 1983.\n\n \n\nBackground:  The manufacturer advises that it may be necessary to re-route and modify the airconditioning ducting located above the electrical overhead panel due to the possibility of electrical arcing or shorting occurring in that area.\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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope, as stated, covers a specific set of MU-2 models and serial numbers and requires inspection/modification prior to the next maintenance release after 21 December 1983 (Applicability; Compliance). There is no text in the document indicating a change from an earlier or different scope; the stated applicability and compliance timing define the scope directly (Applicability; Compliance)."},"complexity_factors":["Narrow, clearly listed applicability by model and serial number (Applicability)","Single, short compliance deadline tied to the next maintenance release after a specific date (Compliance)","Technical detail delegated to a single manufacturer service bulletin (Document), creating dependency on external technical instructions","Work involves airframe modification and inspection, which requires qualified maintenance personnel and incurs downtime and parts costs (Applicability; Document)","Limited scope reduces legal and administrative complexity but requires operational scheduling coordination by each operator (Compliance)"],"plain_english_summary":"This directive requires owners/operators of specified Mitsubishi MU-2B-26A/-40 and MU-2B-36A/-60 serial-numbered aeroplanes to inspect cockpit air‑conditioning ducting above the electrical overhead panel and, if needed, re‑route or modify it per the manufacturer’s service bulletin. Work must be completed before the next maintenance release after 21 December 1983. The measure—paid for by operators—implements the manufacturer’s advice to reduce risk of electrical arcing or shorting."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive targeting a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of mandating a single inspection and modification."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability groups (specific aircraft models and serial number ranges)","Single compliance deadline with clear trigger event (next maintenance release after fixed date)","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","No conditional logic or exceptions","Single technical reference document (manufacturer's Service Bulletin)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Mitsubishi MU-2 aircraft. It requires owners and operators to inspect and modify the cockpit air-conditioning ducts on certain plane models and serial numbers. The modification prevents electrical fires or short circuits that could occur if the ducting touches the electrical panel above the pilot's head. The work must be done before the plane's next maintenance certificate is issued after 21 December 1983, following instructions in the manufacturer's Service Bulletin No. 040/21-002."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification","history":"/api/acts/ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification/history","analysis":"/api/acts/ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification/analysis","conflicts":"/api/acts/ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification/important-cases","documents":"/api/acts/ad-mu-2-31-cockpit-airconditioning-ducts-inspection-and-modification/documents"}}