{"id":"F2006B10722","name":"AD/HU 369/59 Amdt 1 - Main Transmission Oil Lines","slug":"ad-hu-369-59-amdt-1-main-transmission-oil-lines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116705,"registerId":"commonwealth-F2006B10722-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/59 Amdt 1 - Main Transmission Oil Lines","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)  \nMcDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\nAD/HU 369/59\n\nAmdt 1\n\n  \nMain Transmission Oil Lines 7/87\n\nApplicability: All model 369D, 369E, 369F and 369FF helicopters fitted with rigid oil lines in the main transmission cooling installation.\n\nRequirement: 1. Inspect in accordance with Hughes Service Information Notice EN-10 and DN- 124, Part 1.\n\n2. Action in accordance with Hughes Service Information Notice DN-145, EN-33 and FN-22.\n\nCompliance: For Part 1: Within 100 hours time in service after 30 June 1987 and thereafter at intervals not exceeding 100 hours time in service until modified in accordance with Part 2 of the Requirement.\n\nFor Part 2: Whenever damaged rigid lines need to be replaced or at the next main transmission overhaul after 30 June 1987 whichever occurs first.\n\nBackground: The manufacturer considers it necessary to introduce a periodic inspection of the subject oil lines for chafing damage which could ultimately cause the loss of oil feed to the transmission. This Directive has been amended to increase the applicable aircraft and introduce the modification which replaces rigid lines with flexible lines.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1553},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The amendment expands coverage to include additional aircraft models (specifically the 369FF variant) and introduces a new modification requirement allowing operators to permanently replace problematic rigid oil lines with flexible alternatives, whereas the original directive appears to have only mandated recurring inspections without offering a terminating modification action."},"complexity_factors":["Single, specific technical subject matter (oil lines on four helicopter models)","No definitions section or complex legal terminology","Clear two-step compliance path (inspect, then modify)","Straightforward time-in-service compliance intervals (100 hours)","No nested exceptions or conditional logic beyond simple 'whichever occurs first' timing"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified McDonnell Douglas (Hughes) and Kawasaki 369 helicopter models with rigid metal main-transmission cooling oil lines to inspect those lines for chafing every 100 flight hours and to replace rigid lines with flexible ones when a line is damaged or at the next main-transmission overhaul. \n\nChafing can cause oil loss and transmission seizure, risking catastrophic loss of control. This revision broadens affected models and adds the flexible-line replacement as a permanent fix."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-59-amdt-1-main-transmission-oil-lines","history":"/api/acts/ad-hu-369-59-amdt-1-main-transmission-oil-lines/history","analysis":"/api/acts/ad-hu-369-59-amdt-1-main-transmission-oil-lines/analysis","conflicts":"/api/acts/ad-hu-369-59-amdt-1-main-transmission-oil-lines/conflicts","importantCases":"/api/acts/ad-hu-369-59-amdt-1-main-transmission-oil-lines/important-cases","documents":"/api/acts/ad-hu-369-59-amdt-1-main-transmission-oil-lines/documents"}}