{"id":"F2006B11396","name":"AD/MU-2/66 - Flight Test","slug":"ad-mu-2-66-flight-test","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57297,"registerId":"commonwealth-F2006B11396-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MU-2/66 - Flight Test","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-2/66 Flight Test 4/99\n\nApplicability: Mitsubishi Heavy Industries (MHI) Model MU-2B-10, \\-15, \\-20, \\-25, \\-26 aeroplanes\n\nserial number 008 through 347, other than 313 and 321, and MU-2B-30, \\-35, \\-36\n\naeroplanes serial number 501 through 696 other than 652 and 661.\n\nRequirement: To prevent possible inappropriate adjustment of the flight idle fuel flow settings and propeller rigging resulting in degraded performance, carry out an operating crew only, non revenue, flight check in accordance with the procedures detailed in MHI MU-2 Service Bulletin Number 234.\n\nNote: Japan Civil Aviation Bureau Airworthiness Directive TCD-4890-98 refers.\n\nCompliance: Within 6 months time in service from the effective date of this directive or at the next periodic inspection, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 22 April 1999.\n\nBackground: The purpose of the flight test is to evaluate the engine flight idle fuel flow settings and propeller rigging. Incorrect fuel flow settings and propeller rigging can result in unsafe flight characteristics including inadvertent occurrence of negative torque sensing mode during a landing approach.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific technical safety issue with a specific aircraft type. It has not expanded beyond its original purpose of mandating a flight test to verify engine and propeller settings."},"complexity_factors":["Single, specific technical requirement with clear procedural reference (MHI Service Bulletin 234)","Limited applicability scope (specific aircraft models and serial numbers only)","Straightforward compliance timeline (6 months or next inspection)","No nested exceptions or conditional logic — only simple serial number exclusions","Minimal defined terms (only standard aviation terminology like 'flight idle' and 'negative torque sensing' which are explained in context)","Short length (under 300 words)","Single cross-reference to Japanese aviation authority directive for background only"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified Mitsubishi MU-2B aeroplanes to conduct a non-revenue special flight test, following the Mitsubishi service bulletin, to verify flight idle fuel flow and propeller rigging. It addresses a risk of entering negative torque sensing mode on approach, which can dangerously affect control.\n\nCompliance is required within six months of the directive (or at the next scheduled inspection), for the listed MU-2B serial numbers."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive targets a defined set of MU‑2 models/serial numbers to evaluate and correct idle fuel flow and propeller rigging, matching the stated safety purpose in the Background. It does not expand or narrow the subject matter beyond that stated aim."},"complexity_factors":["Narrow applicability: specific MU‑2B models and discrete serial number ranges require tracking which aircraft are affected (Applicability).","Prescriptive procedure: flight check must follow MHI Service Bulletin No.234, requiring access to and adherence to manufacturer guidance (Requirement).","Operational constraint: the check is an operating‑crew, non‑revenue flight test, which affects scheduling and crew duty planning (Requirement).","Compliance timing: action must occur within six months or at the next periodic inspection, creating a hard deadline for operators (Compliance).","Technical trigger: background links the measure to specific technical risks (idle fuel flow and propeller rigging) that can produce unsafe flight characteristics, requiring technical competence to assess (Background).","Regulatory cross‑reference: the directive notes a related Japan AD, indicating international coordination and possible harmonisation of corrective action (Note)."],"plain_english_summary":"This directive requires operators of specified Mitsubishi MU‑2 models and serial numbers to have the operating crew perform a non‑revenue flight check, using the procedures in MHI Service Bulletin No.234, to verify engine flight idle fuel flow settings and propeller rigging. The Civil Aviation Safety Authority issued the requirement; operators must comply within six months or at the next periodic inspection. It addresses a safety risk: incorrect settings can cause degraded performance and inadvertent negative torque sensing during landing approach."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-66-flight-test","history":"/api/acts/ad-mu-2-66-flight-test/history","analysis":"/api/acts/ad-mu-2-66-flight-test/analysis","conflicts":"/api/acts/ad-mu-2-66-flight-test/conflicts","importantCases":"/api/acts/ad-mu-2-66-flight-test/important-cases","documents":"/api/acts/ad-mu-2-66-flight-test/documents"}}