{"id":"F2006B11345","name":"AD/MU-2/17 Amdt 4 - Elevator Trim Tab Bracket - Inspection and Replacement","slug":"ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57228,"registerId":"commonwealth-F2006B11345-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MU-2/17 Amdt 4 - Elevator Trim Tab Bracket - Inspection and Replacement","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-2/17\n\nAmdt 4\n\n  \n\nElevator Trim Tab Bracket \\- Inspection and Replacement\n\n  \n1/85\n\nApplicability: All models MU-2B/-10/-15/-20/-25/-26: S/Nos. 005 through 347 (except S/Nos.\n\n313,321).\n\nAll models MU-2B-30/-35/-36: S/Nos. 501 through 696 (Except S/Nos. 652,661). All models MU-2B-25/-26/-26A/-40: S/Nos. 313SA/ 321SA, 348SA through 449SA. All models MU-2B-35/-36A/-60: S/Nos. 652SA, 661SA, 697SA through 1530 SA.\n\nDocument: 1. Mitsubishi SB No. 176 Revision E, or\n\n2. Mitsubishi Aircraft International SB No. SBO 31/27-005.\n\nNote: JCAB AD No. TCD-1001B-2-84 also refers.\n\nCompliance: Unless already accomplished, as detailed in the requirement document.\n\nBackground: This Directive has been amended to include revised requirement document references.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains focused on its original purpose — elevator trim tab bracket inspection and replacement for Mitsubishi MU-2 aircraft. The amendment simply updates document references without expanding the scope to new aircraft types or systems."},"complexity_factors":["Multiple serial number ranges with specific exclusions (e.g., 'S/Nos. 005 through 347 (except S/Nos. 313,321)')","Cross-reference to two alternative technical documents for compliance","Reference to a Japanese aviation authority directive (JCAB AD No. TCD-1001B-2-84) for additional context","Amendment history (4th revision) requiring tracking of changes from previous versions"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Mitsubishi MU-2 series aircraft**.\n\n**What it does:**\n- Requires owners and operators of specific Mitsubishi MU-2 aeroplanes to **inspect and replace the elevator trim tab bracket** — a critical control surface component that helps stabilise the aircraft in flight.\n- The directive applies to specific **serial numbers** of various MU-2 models (MU-2B, MU-2B-10 through -60, and others), with some exceptions noted.\n\n**Who must comply:**\n- Owners and operators of the affected aircraft models and serial numbers listed in the \"Applicability\" section.\n\n**Why it matters:**\n- Elevator trim tab brackets are essential for safe flight control. If these brackets fail, pilots could lose control of the aircraft's pitch (nose up/down movement), creating a serious safety risk.\n- This is the **4th amendment** to the original directive, updated to reference newer technical documents from Mitsubishi.\n\n**What you need to do:**\n- Follow the inspection and replacement procedures in either:\n  - Mitsubishi Service Bulletin No. 176 Revision E, **or**\n  - Mitsubishi Aircraft International Service Bulletin SBO 31/27-005\n- Compliance is required unless the work has already been completed."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Background statement says the Directive was amended to include revised requirement document references. The Applicability section (the list of affected models and serial numbers) remains the controlling scope in the AD. The amendment therefore updates which service-bulletin documents to follow rather than expanding or narrowing the aircraft population to which the AD applies. (Background; Applicability)"},"complexity_factors":["Applicability is granular: specific models plus serial-number ranges with listed exceptions (requires careful serial-number checking). (Applicability)","The AD delegates all procedural detail to external service bulletin(s) rather than stating inspection method, intervals, or acceptance criteria directly. (Document; Compliance)","Two alternative service-bulletin references are given; operators must confirm and obtain the correct revision. (Document)","The AD text is short on timing, parts supply, and operational impacts, so implementers must consult additional documents to assess practical costs and scheduling. (Document; Compliance)","A related foreign AD is referenced (JCAB), which may require cross-referencing. (Note)"],"plain_english_summary":"This AD requires owners/operators of the specified Mitsubishi MU-2 serial-numbered aeroplanes to have the elevator trim‑tab bracket inspected—and replaced if necessary—by following the named Mitsubishi service bulletin revision. Compliance (and costs) are the responsibility of the owner/operator; applicability is limited to the MU‑2s listed in the AD, which was amended only to reference revised service‑bulletin documents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement","history":"/api/acts/ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement/history","analysis":"/api/acts/ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement/important-cases","documents":"/api/acts/ad-mu-2-17-amdt-4-elevator-trim-tab-bracket-inspection-and-replacement/documents"}}