{"id":"F2006B11343","name":"AD/MU-2/15 - Main Landing Gear Door Mechanism Support - Inspection","slug":"ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57224,"registerId":"commonwealth-F2006B11343-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MU-2/15 - Main Landing Gear Door Mechanism Support - Inspection","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-2/15 Main Landing Gear Door Mechanism\n\nSupport - Inspection\n\nApplicability: All model MU-2B-30/-35 with S/Nos. 501 to 585. Document:  Mitsubishi SB No. 172.\n\n# 1/76\n\nCompliance: Within 100 hours time in service after 27 February 1976 and there- after at intervals not exceeding 100 hours time in service until modified in accordance with SB No. 172.\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 discrete, time-limited safety directive from 1976 with a narrow, specific scope (one aircraft type, one mechanical component). It has not expanded beyond its original purpose of ensuring landing gear door mechanism integrity pending permanent modification."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (model numbers and serial number range)","Single compliance requirement with clear time-based trigger (100 hours time in service)","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","No nested conditions or exceptions — straightforward 'inspect until modified' instruction","Single technical reference (Mitsubishi SB No. 172)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it requires:** Owners and operators of specific Mitsubishi MU-2B aeroplanes (serial numbers 501 to 585) must **inspect the main landing gear door mechanism support** within 100 hours of flying time after 27 February 1976, and then **re-inspect it every 100 hours of flying time** until they install a permanent fix (Service Bulletin No. 172).\n\n**Who it affects:** Anyone operating the affected Mitsubishi MU-2B-30 or MU-2B-35 aircraft models in Australia.\n\n**Why it matters:** The landing gear door mechanism support was apparently prone to failure or wear. Without regular inspection, this could lead to landing gear problems — potentially catastrophic during takeoff or landing. The directive forces operators to check for problems frequently until a permanent modification is made."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD, as drafted, applies to the stated models and serial numbers and prescribes inspection intervals until modification per Mitsubishi SB No. 172. There is no indication within the text provided that the scope deviates from the instrument's expressed aim; the directive remains targeted to the specified aircraft and prescribes the stated compliance regime. (Applicability; Compliance; Document)"},"complexity_factors":["Narrow applicability limited to specific models and serial-number range (MU-2B-30/-35, S/N 501–585). (Applicability)","Single, simple recurring requirement with a fixed interval (every 100 hours TIS) and a clear cutoff if modification is accomplished. (Compliance)","Dependence on an external technical document (Mitsubishi SB No. 172) for modification details increases practical complexity for implementation but not for the AD's content. (Document: Mitsubishi SB No. 172)","Fixed historical reference date (27 February 1976) means timing is measured from that date, which can be administratively notable for record checks. (Compliance)","Limited procedural detail in the AD (no enforcement/record-keeping text, no technical steps) requiring operators to consult the Service Bulletin for technical instructions. (Compliance; Document)"],"plain_english_summary":"This Airworthiness Directive from the Civil Aviation Safety Authority requires owners/operators of Mitsubishi MU-2B-30 and MU-2B-35 aircraft (S/N 501–585) to inspect the main landing gear door mechanism support within 100 hours TIS after 27 Feb 1976 and every 100 hours thereafter until modified per Mitsubishi Service Bulletin No. 172. Operators fund the inspections or can eliminate recurring checks by completing the SB 172 modification."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection","history":"/api/acts/ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection/history","analysis":"/api/acts/ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection/analysis","conflicts":"/api/acts/ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection/conflicts","importantCases":"/api/acts/ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection/important-cases","documents":"/api/acts/ad-mu-2-15-main-landing-gear-door-mechanism-support-inspection/documents"}}