{"id":"F2007L00566","name":"AD/MU-2/65 Amdt 1 - Engine Torque Indication System","slug":"ad-mu-2-65-amdt-1-engine-torque-indication-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":63899,"registerId":"commonwealth-F2007L00566-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Mitsubishi MU-2 Series Aeroplanes","sectionType":"division","heading":"Mitsubishi MU-2 Series Aeroplanes","content":"### Mitsubishi MU-2 Series Aeroplanes\n\n| AD/MU-2/65 Amdt 1 | Engine Torque Indication System | 4/2007 DM |\n| ----------------- | ------------------------------- | --------- |\n\n| Applicability: | Model MU-2B, -10, -15, -20, -25 and -26 aeroplanes, serial number (S/N) 008 through 347 (except for S/N 313 and 321) and Model MU-2B-30, -35 and -36 aeroplanes S/N 501 through 696 (except S/N 652 and 661). |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. For MU-2B, -10, -15, -20 and -30 aeroplanes: |\n| | a. If not previously accomplished in accordance with the original issue of this Directive, inspect the torque indication system in accordance with Mitsubishi Heavy Industries (MHI) MU-2 Service Bulletin (SB) No. 233A dated14 January 1999 or later revision approved by the Japan Civil Aviation Bureau (JCAB). |\n| | b. If, during the Requirement 1 inspection, the errors in the torque indication system are found to exceed the allowable limit specified in the SB, repair or replace the torque transmitter in accordance with the SB. |\n| | 2. For MU-2B-25, -26, -35 and -36 aeroplanes: |\n| | a. If not previously accomplished in accordance with the original issue of this Directive, inspect the torquemeter in accordance with MHI SB No. 233A or later revision approved by the Japan Civil Aviation Bureau (JCAB). |\n| | b. If, during the Requirement 1 inspection, the errors in the torque indication system are found to exceed the allowable limit specified in the SB, repair or replace the torquemeter in accordance with the SB. |\n| | c. If not previously accomplished in accordance with the original issue of this Directive, inspect the torque transducer in accordance with MHI SB No. 233A or later revision approved by the Japan Civil Aviation Bureau (JCAB). |\n| | d. If, during the Requirement 3 inspection, the torque transducer output voltage is found to exceed the allowable limit specified in the SB, adjust the torque transducer output voltage in accordance with the SB. |\n\n| | 3. Accomplish a ground check of the engines in accordance with paragraph 3 of MHI SB No. 233A or later revision approved by the Japan Civil Aviation Bureau (JCAB). |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Note 1: The holder of a Certificate of Registration of an Australian aircraft is required under Civil Aviation Regulation 55 to ensure that the Aircraft Flight Manual (AFM) is amended to the current approved revision. |\n| | 4. Repair any discrepancies noted during the Requirement 1 check. |\n| | Note 2: JCAB AD TCD-4889-1-2006 refers. |\n| Compliance: | For Requirement 1.a. - Within 100 hours time in service (TIS) after the effective date of this Amendment. |\n| | For Requirement 1.b. - Before further flight after the Requirement 1.a. inspection. |\n| | For Requirement 2.a. - Within 100 hours TIS after the effective date of this Amendment. |\n| | For Requirement 2.b. - Before further flight after the Requirement 2.a. inspection. |\n| | For Requirement 2.c. - Within 100 hours TIS after the effective date of this Amendment. |\n| | For Requirement 2.d. - Before further flight after the Requirement 2.c. inspection. |\n| | For Requirement 3 - Within 100 hours TIS after the effective date of this Amendment. |\n| | For Requirement 4 - Before further flight after the Requirement 3 check. |\n| | This Amendment becomes effective on 9 March 2007. |\n| Background: | MHI reports that some torque transmitter or transducers have been found significantly out of calibration. This can result in an actual power mismatch that is not indicated on the engine instruments. Mismatched power and resulting trim may result in degraded performance or handling qualities. |\n| | The original issue of this Directive required the inspection and, if necessary, the repair, replacement or calibration of the torque indication system. |\n| | This amendment introduces a ground check of the engines following the inclusion of a Power Assurance Chart in the AFM. |\n\n| | The original issue of this Directive became effective on 10 March 1999. |\n| --- | ----------------------------------------------------------------------- |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n28 February 2007","sortOrder":0},{"sectionNumber":"AD/MU-2/65 Amdt 1","sectionType":"part","heading":"AD/MU-2/65 Amdt 1","content":"## AD/MU-2/65 Amdt 1","sortOrder":1},{"sectionNumber":"Engine Torque Indication System","sectionType":"part","heading":"Engine Torque Indication System","content":"## Engine Torque Indication System","sortOrder":2},{"sectionNumber":"4/2007 DM","sectionType":"part","heading":"4/2007 DM","content":"## 4/2007 DM","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose — ensuring accurate engine torque indication on MU-2 aircraft. The amendment adds one new requirement (the ground check in Requirement 3) to complement the existing inspection and repair regime, reflecting an evolution in the manufacturer's technical guidance rather than scope creep. The original 1999 directive addressed the calibration safety issue; this 2007 amendment simply incorporates a subsequent technical improvement (the Power Assurance Chart) without expanding beyond the torque indication system."},"complexity_factors":["Multiple aircraft model variants with different requirements (MU-2B, -10, -15, -20, -25, -26, -30, -35, -36)","Serial number ranges with specific exclusions (4 exceptions listed)","Different inspection requirements for different model groups (Requirements 1 vs 2)","Cross-references to external technical documents (Mitsubishi Service Bulletin 233A and Japan Civil Aviation Bureau approvals)","Interdependent compliance deadlines (Requirement 1.b. must occur after 1.a., etc.)","Nested conditional logic ('if not previously accomplished', 'if errors found exceed allowable limit')","Reference to Civil Aviation Regulation 55 for flight manual amendments"],"plain_english_summary":"This AD mandates inspections and corrective action on the engine torque indication systems of specified Mitsubishi MU-2 aeroplanes because some torque transmitters/transducers were found significantly out of calibration. Affected owners/operators must inspect, repair/replace out-of-tolerance components, perform required torque-transducer checks and a ground power check, and correct any discrepancies—generally within 100 flight hours and before further flight. It amends a 1999 directive by adding the ground check tied to an AFM Power Assurance Chart update."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This amendment retains the original inspection/repair/calibration requirements but adds a compulsory ground engine check after a Power Assurance Chart is inserted in the Aircraft Flight Manual and makes explicit the AFM amendment obligation (Note 1). The net scope increased to include an operational ground check and an administrative AFM update, while still relying on SB No.233A (JCAB‑approved) procedures and existing corrective actions."},"complexity_factors":["Multiple model and serial‑number applicability with specific inclusions and exclusions (MU‑2B/10/15/20/25/26/30/35/36, varied S/N ranges)","Different actions required by model group (inspect/repair/replace/adjust torque transmitter, torquemeter, torque transducer)","Conditional triggers: ‘if not previously accomplished’ and ‘if errors exceed allowable limit’ create dependency on maintenance history","Cross‑reference to external technical document Mitsubishi SB No.233A and requirement for JCAB approval of later revisions","Tight, staged compliance deadlines (100 hours TIS or ‘before further flight’ for corrective actions)","Addition of AFM amendment obligation under Civil Aviation Regulation 55 (administrative compliance cost)","Requirement to perform a ground engine check tied to inclusion of a Power Assurance Chart in the AFM","Reference to a foreign AD (JCAB AD TCD‑4889‑1‑2006) and international regulatory coordination"],"plain_english_summary":"This amendment requires specified Mitsubishi MU‑2 aeroplanes to have their engine torque‑indication components inspected and, if out of tolerance, repaired, replaced or adjusted in accordance with Mitsubishi SB No.233A as approved by the Japan Civil Aviation Bureau. It also adds a mandatory ground engine check after a Power Assurance Chart is placed in the Aircraft Flight Manual. Aircraft owners/operators (the Certificate of Registration holder) must arrange and pay for the work and update the AFM; compliance timings are 100 hours TIS or before further flight as specified."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-65-amdt-1-engine-torque-indication-system","history":"/api/acts/ad-mu-2-65-amdt-1-engine-torque-indication-system/history","analysis":"/api/acts/ad-mu-2-65-amdt-1-engine-torque-indication-system/analysis","conflicts":"/api/acts/ad-mu-2-65-amdt-1-engine-torque-indication-system/conflicts","importantCases":"/api/acts/ad-mu-2-65-amdt-1-engine-torque-indication-system/important-cases","documents":"/api/acts/ad-mu-2-65-amdt-1-engine-torque-indication-system/documents"}}