{"id":"F2006B10575","name":"AD/HU 269/10 - Lower Coupling Drive Shaft - Inspection and Replacement","slug":"ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116413,"registerId":"commonwealth-F2006B10575-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 269/10 - Lower Coupling Drive Shaft - Inspection and Replacement","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\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)  Schweizer (Hughes) 269 Series Helicopters\n\n \n\n# AD/HU 269/10 Lower Coupling Drive Shaft - Inspection\n\nand Replacement\n\nApplicability: Model 269A with S/Nos. 0011 to 0314.\n\n \n\nModel 269A-1 with S/Nos. 0001 to 0007. Model 269B with S/Nos. 0001 to 0079.\n\n# 4/64\n\nRequirement: 1. Remove the lower coupling drive shaft (P/N 269A5504) and conduct a dye penetrant or magnetic particle inspection of the shaft. Pay particular attention to the radii at the end splines, alignment collar and boot mounting collar. Replace any shaft exhibiting evidence of cracking before further flight.\n\n \n\n2.    Replace the lower drive shaft coupling P/N 269A5504 with shaft P/N 269A5504-3.\n\n \n\n3.    Hughes SIN 2A-3, 2A-1-01, 2B-01 and FAA AD 64-6-4 also refer.\n\n \n\nCompliance: For Para. 1 - At intervals not exceeding 100 hours time in service until the accomplishment of para. 2 above.\n\n \n\nFor Para. 2 - Within 500 hours time in service. The shaft P/N 269A5504 must not exceed 1,500 hours total time in service.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical failure mode in specific aircraft. It has not expanded beyond its original purpose of preventing drive shaft failures."},"complexity_factors":["Single mechanical component addressed (lower coupling drive shaft)","Only 3 specific helicopter models affected with defined serial number ranges","Straightforward two-stage compliance: interim inspection (100-hour intervals) and ultimate replacement (500-hour deadline)","Simple cross-reference to 4 related service bulletins/directives","No nested exceptions or conditional logic beyond the serial number applicability","Clear time-in-service metrics for compliance (100 hours, 500 hours, 1,500 hours total)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of early-model Schweizer/Hughes 269A/A‑1/B helicopters to inspect the lower coupling drive shaft for cracks, and to replace the original shaft with an improved design within 500 flight hours (hard retirement at 1,500 hours).  \n\nIt’s mandatory because drive‑shaft fatigue can cause sudden power loss and catastrophic rotor failure; the inspections and replacement reduce that risk."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The instrument applies as written to the specified models and serial ranges and sets out inspection and mandatory replacement requirements, with defined intervals and a life limit for the old shaft. The document itself does not indicate any expansion or narrowing of applicability beyond those stated requirements."},"complexity_factors":["Technical inspection requirement: non‑destructive testing (dye penetrant or magnetic particle) focused on spline radii, alignment collar and boot mounting collar — requires trained technicians and equipment.","Multiple compliance timeframes: inspections every 100 hours until replacement; replacement within 500 hours; maximum life 1,500 hours for the old part.","Parts management: specific part numbers (P/N 269A5504 and replacement P/N 269A5504‑3) require sourcing, inventory and fitment tracking.","Applicability by model and serial number ranges narrows affected operators and requires accurate fleet records.","Cross‑references to Hughes Service Information Notices and FAA ADs introduce additional documents to consult for full compliance.","Operational impact: recurring maintenance scheduling and potential aircraft downtime until replacement completed.","Regulatory enforcement context under the Civil Aviation Regulations Part 39 requires recordkeeping and demonstrated compliance."],"plain_english_summary":"This Airworthiness Directive requires operators of Schweizer (Hughes) 269A, 269A‑1 and 269B helicopters in the listed serial ranges to inspect the lower coupling drive shaft (P/N 269A5504) for cracking using dye‑penetrant or magnetic‑particle methods, replace any cracked shaft before further flight, and fit replacement shaft P/N 269A5504‑3 within 500 flight hours; the original shaft must not exceed 1,500 hours. It places recurring inspection, parts procurement and replacement costs and scheduling obligations on operators (inspections every 100 hours until replacement)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement","history":"/api/acts/ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement/history","analysis":"/api/acts/ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement/important-cases","documents":"/api/acts/ad-hu-269-10-lower-coupling-drive-shaft-inspection-and-replacement/documents"}}