{"id":"F2006B10740","name":"AD/HU 369/76 Amdt 1 - Engine to Transmission Drive Shaft Couplings","slug":"ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116741,"registerId":"commonwealth-F2006B10740-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/76 Amdt 1 - Engine to Transmission Drive Shaft Couplings","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 369/76\n\nAmdt 1\n\n  \nEngine to Transmission Drive Shaft Couplings 5/90\n\nApplicability: All model 369 series helicopters, fitted with a driveshaft coupling within the S/N range 5200 thru 5309.\n\nRequirement: Action in accordance with McDonnell Douglas SIN No HN-216, DN-157, EN-47 or FN-35, as applicable. If the S/N cannot be identified the coupling must be replaced unless its history is known and can be tracked to delivery. McDonnell Douglas will advise S/N fitted to specific aircraft at delivery upon request.\n\nNote: FAA AD 90.01.08 Amdt 39-6456 refers.\n\nCompliance: At next periodic inspection for issue of a Maintenance Release or by 15 August 1989, whichever occurs first.\n\nBackground: Due to possible cracking of the transmission driveshaft coupling a one time inspection of the coupling serial number against the serial number listing contained in the compliance document is required.\n\nThis Amendment clarifies Requirements for those couplings that have lost the S/N decal.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: ensuring the safety of a specific helicopter part. The amendment merely clarifies what to do when serial number decals are missing—it does not expand the scope to other aircraft, parts, or maintenance requirements."},"complexity_factors":["Very short document (under 200 words)","Only 1 defined applicability criterion (serial number range)","Single compliance action with clear alternative paths (inspect if S/N known, replace if unknown)","No nested exceptions or conditional logic beyond the S/N identification clause","Minimal cross-referencing (only one FAA AD reference and manufacturer service bulletins)"],"plain_english_summary":"This safety directive mandates a one-time inspection (or replacement) of the driveshaft coupling on McDonnell Douglas (Hughes) and Kawasaki 369 series helicopters if its serial number falls within 5200–5309. Operators and maintainers must follow manufacturer instructions; missing serial decals require replacement or full provenance. CASA enforces the rule to prevent in-flight engine-to-transmission disconnection from cracked couplings. Deadline: by the next maintenance or 15 August 1989."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment clarifies identification and replacement procedures for couplings that have lost their serial-number decal but does not expand the set of affected aircraft or add new substantive obligations beyond the original directive."},"complexity_factors":["Narrow applicability: applies only to 369-series helicopters with couplings S/N 5200–5309","Conditional requirement: replacement mandatory if S/N cannot be identified, but allowed if delivery history can be reliably traced","Cross-references to multiple manufacturer documents (SIN HN-216, DN-157, EN-47 or FN-35) that determine specific actions","Fixed compliance window (next maintenance-release inspection or a specified calendar date), creating scheduling constraints","Administrative burden on operators to check S/Ns, retain/trade delivery history and liaise with manufacturer for identification","Clarification for lost S/N decals increases procedural detail but does not add new technical tests","Reliance on one-time inspection reduces ongoing monitoring complexity but concentrates cost/risk at inspection point","Potential parts supply and downtime costs if couplings must be replaced following inspection"],"plain_english_summary":"This airworthiness directive forces operators of McDonnell Douglas (Hughes)/Kawasaki 369-series helicopters fitted with driveshaft couplings S/N 5200–5309 to verify the coupling serial number against the manufacturer’s listing and to replace the coupling if the number cannot be identified (unless delivery history is traceable). Compliance is required at the next maintenance-release inspection or by 15 August 1989. The stated purpose is to detect possible coupling cracking; meeting it shifts identification, inspection and replacement costs and record-keeping onto aircraft operators and requires cooperation with the manufacturer."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings","history":"/api/acts/ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings/history","analysis":"/api/acts/ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings/analysis","conflicts":"/api/acts/ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings/conflicts","importantCases":"/api/acts/ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings/important-cases","documents":"/api/acts/ad-hu-369-76-amdt-1-engine-to-transmission-drive-shaft-couplings/documents"}}