{"id":"F2006B10674","name":"AD/HU 369/115 - Fuselage Station 75 Control Support Bracket Assembly","slug":"ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116612,"registerId":"commonwealth-F2006B10674-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/115 - Fuselage Station 75 Control Support Bracket Assembly","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nMcDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\nAD/HU 369/115 Fuselage Station 75 Control Support Bracket Assembly\n\n  \n1/2005\n\nDM\n\nApplicability: Model 600N helicopters, serial numbers with a prefix of “RN” and numbers 025, 029, 032, 034 through 038, 040, 041, 045, 048, or 067; or, any Model 600N helicopter with a yaw stability augmentation system (YSAS) installed, and with a control support bracket assembly, part number 369N2608-11, installed.\n\nRequirement: 1. Replace the fuselage Station 75 control support bracket assembly, part number 369N2608-11, with a serviceable control support bracket assembly, part number 600N2608-1.\n\nHelicopter serial numbers and revised finite life (time in service) list:\n\nRN025 2556 hrs, RN029 2377 hrs, RN032 2498 hrs, RN034 2456 hrs, RN035\n\n2243 hrs, RN036 2652 hrs, RN037 2544 hrs, RN038 2531 hrs, RN040 2562\n\nhrs, RN041 2763 hrs, RN045 2015 hrs, RN048 2125 hrs, and RN067 1600 hrs.\n\n2. For helicopters with a YSAS installed that are not listed in above serial number and revised finite life list, replace the control support bracket assembly part number 369N2608-11 with a serviceable control support bracket assembly, part number 600N2608-1.\n\nFor helicopters with no YSAS installed, but with a control support bracket assembly part number 369N2608-11 installed, replace the control support bracket assembly part number 600N2608-1, before installation of a YSAS.\n\nThis Directive revises the Limitations section of the applicable maintenance manual by reducing the life limit of the control support bracket assembly, part number 369N2608-11, to the life limits stated in the above serial number and revised finite life list or to 1,600 hours time in service, whichever occurs first.\n\nNote 1: MD Helicopters, Inc. Service Bulletin No. SB600N-040, dated 18 September 2003, refers.\n\nNote 2: FAA AD 2004-22-12 Amdt 39-13840 refers.\n\nMcDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\nAD/HU 369/115 (continued)\n\nCompliance: 1. Before 1 December 2005 or upon accumulating the time listed in the serial number and revised finite life list in the Requirement part of this Directive; whichever occurs first.\n\n2. Before 1 December 2005 or upon accumulating 1,600 hours time in service since installation of the YSAS, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 8 December 2004.\n\nBackground: This Directive is prompted by information received from the manufacturer indicating that the fatigue life of the control support bracket is shorter than the original analysis indicated. The actions required by this Directive are intended to prevent failure of the control support bracket and subsequent loss of control of the helicopter.\n\n![](image.002.png)  \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 2 December 2004\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 8 December 2004.","sortOrder":0}],"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":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific fatigue life issue with a specific bracket on a specific helicopter model. The serial-number-specific hour limits and YSAS distinctions reflect precision targeting rather than scope creep."},"complexity_factors":["Multiple applicability categories requiring cross-referencing (specific serial numbers vs. YSAS-equipped vs. non-YSAS with future installation plans)","Dual compliance deadlines for each category (calendar date vs. flight hours, whichever occurs first)","Part number tracking required (369N2608-11 vs. 600N2608-1)","Serial-number-specific flight hour limits (13 different hour thresholds)","Conditional logic for YSAS installation status affecting both applicability and compliance timing","Reference to external documents (Service Bulletin SB600N-040 and FAA AD 2004-22-12) without full incorporation"],"plain_english_summary":"Owners and operators of certain McDonnell Douglas (Hughes) Model 600N helicopters must replace a fatigue-prone fuselage Station 75 control support bracket with a new part. The AD applies to listed serial numbers, any 600N with a YSAS and the bracket, and helicopters planning to install YSAS. Replacement is required by 1 December 2005 or specified flight-hour limits to prevent bracket failure and possible loss of control."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This AD narrows the allowable service life of control support bracket P/N 369N2608-11 and mandates replacement with P/N 600N2608-1 for listed serials and for any Model 600N with a YSAS (Applicability; Requirement). It revises maintenance‑manual limits and extends mandatory replacement beyond the originally stated life by imposing a 1,600‑hour default and date deadlines (Requirement; Compliance)."},"complexity_factors":["Technical specificity: applicability tied to model, specific serial numbers and two distinct part numbers (Applicability; Requirement).","Conditional rules: different obligations depending on whether a YSAS is installed and whether the helicopter appears on the serial-number list (Requirement).","Life‑limit logic: revised finite life list with a ‘‘whichever occurs first’’ trigger (Requirement; Compliance).","Timing triggers: compliance set by calendar date or accumulated hours, creating dual compliance paths (Compliance).","Maintenance impact: requires amendment of the maintenance manual Limitations section, altering ongoing maintenance obligations (Requirement).","External dependencies: refers to a manufacturer service bulletin and an FAA AD, linking compliance interpretation to external documents (Notes)."],"plain_english_summary":"This Airworthiness Directive requires replacing the fuselage Station 75 control support bracket assembly (P/N 369N2608-11) with P/N 600N2608-1 on specified McDonnell Douglas (Hughes) and Kawasaki 369 Model 600N helicopters. CASA says manufacturer data show the bracket’s fatigue life is shorter than initially analysed, so the AD reduces the part’s life limit (to listed hours or 1,600 hours) and sets mandatory replacement deadlines. Owners/operators pay for replacements, must amend maintenance limits, and schedule removals per the Requirement and Compliance sections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly","history":"/api/acts/ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly/history","analysis":"/api/acts/ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly/analysis","conflicts":"/api/acts/ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly/conflicts","importantCases":"/api/acts/ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly/important-cases","documents":"/api/acts/ad-hu-369-115-fuselage-station-75-control-support-bracket-assembly/documents"}}