{"id":"F2006B10700","name":"AD/HU 369/39 - Tail Rotor Control Bellcrank Supports - Inspection and Modification","slug":"ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116664,"registerId":"commonwealth-F2006B10700-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/39 - Tail Rotor Control Bellcrank Supports - Inspection and Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 8/1979,Rotorcraft,McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters,Tail Rotor Control Bellcrank Supports - Inspection and Modification,39\ntitle: Airworthiness Directive - AD/HU 369/39 - Tail Rotor Control Bellcrank Supports - Inspection and Modification\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)  McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\n \n\nAD/HU 369/39  Tail Rotor Control Bellcrank Supports - Inspection and Modification\n\n\n8/79\n\n \n\nApplicability: All 500 model 369 series helicopters. All 500D model 369D with S/Nos. 0003D to 0531D, 0533D, 0535D and 0537D.\n\n \n\nDocument: 1. Hughes SIN No. HN-139 for Model 500;\n\n \n\n2. Hughes SIN No. DN-49 for Model 500D.\n\n \n\nCompliance: Inspection - Within 25 hours time in service after 17 July 1979 and thereafter at 100 hour intervals until modified to Part II of the relevant requirement document.\n\n \n\nBackground: Cracks may develop in the tail rotor control bellcrank supports at STN. 142.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1460},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains tightly focused on its original purpose: addressing a specific airworthiness safety defect (potential fatigue cracks in tail rotor control bellcrank supports) for the identified helicopter fleet. There is no evidence of scope expansion beyond this original safety-critical mechanical issue."},"complexity_factors":["Single, specific mechanical issue (tail rotor bellcrank cracks) with no conditional exceptions","Limited applicability restricted to specific aircraft models and serial number ranges","Straightforward compliance timeline (25 hours initial, 100 hour recurring intervals)","References only external technical service bulletins rather than complex legislative cross-references","No defined terms section or nested statutory interpretation provisions"],"plain_english_summary":"This directive requires immediate and recurring inspections and eventual modification of the tail-rotor control bellcrank supports on McDonnell Douglas (Hughes) Model 500 (369-series) and specified Hughes Model 500D helicopters to prevent catastrophic tail-rotor failure. Owners/operators must inspect Station 142 within 25 flight hours after 17 July 1979 and every 100 hours thereafter until the Hughes modification (SIN HN-139 or DN-49) is installed. Cracks could cause loss of directional control and a crash."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification","history":"/api/acts/ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification/history","analysis":"/api/acts/ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification/analysis","conflicts":"/api/acts/ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification/important-cases","documents":"/api/acts/ad-hu-369-39-tail-rotor-control-bellcrank-supports-inspection-and-modification/documents"}}