{"id":"F2006B10748","name":"AD/HU 369/83 Amdt 1 - Tail Rotor Blades","slug":"ad-hu-369-83-amdt-1-tail-rotor-blades","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116757,"registerId":"commonwealth-F2006B10748-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/83 Amdt 1 - Tail Rotor Blades","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 369/83\n\nAmdt 1\n\n  \nTail Rotor Blades 7/91\n\nApplicability: All model 369 Series Helicopters equipped with a Tail Rotor Blade Assembly in the following Part number/Serial Number range:\n\nPart Number Blade Serial Numbers\n\n369A1613 (all dash numbers) Prior to 7959\n\n369D21613 (all dash numbers) Prior to 6482\n\n369D21615 (all dash numbers) Prior to 1358\n\n369D21606 (all dash numbers) Prior to 0538\n\n421-088 ( all dash numbers) Prior to 0218\n\nRequirement: 1. Visually inspect in accordance with part I of Service Information Notice HN- 230.1, DN-177.1, EN-68.1, or FN-55.1, as applicable.\n\n2. Action in accordance with Part II of Service Information Notice HN-230.1, DN- 177.1, EN-68.1, or FN-55.1, as applicable.\n\nNote 1: This Directive shall be entered on the Maintenance Release as maintenance required. The visual inspection required by Para 1 may be performed by the Pilot in command, in which case certification is to be made by entering AD/HU36/83 against the daily inspection certification of the Maintenance Release. A copy of this Airworthiness Directive is to be kept in the aircraft.\n\nNote 2: FAA AD 91-08-02 Amdt 39-6963 refers.\n\nCompliance: 1. Before the first flight of each day, after 18 January 1991.\n\n2. Within 100 hours Time in Service after 18 January 1991 or before 1 March 1991; whichever occurs first.\n\nThe compliance dates of the original issue of this Directive are as stated. This reissue is effective from 11 July 1991.\n\nBackground: Due to a failure of a tail rotor blade root fitting, McDonnell Douglas Helicopter Company (MDHC) is requiring operators to perform an inspection of all aluminium tail rotor blades to ensure that no crack exists in the tail rotor blade root fitting and that the tail rotor blade root fitting has proper wall thickness. Thin wall thickness in the tail rotor blade root fitting can lead to tail rotor blade failure.\n\nMDHC Mandatory Service Documents listed above are considered to be of sufficient Safety of Flight importance, that this Airworthiness Directive was raised without the support of a Country of Origin AD.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nAmdt 1 is raised to introduce a revision to the Requirement documents, and the issue of the FAA AD that now confirms support for this Directive.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: ensuring tail rotor blade safety on specific helicopter models. The amendment merely updates the referenced service documents and notes FAA support — it does not expand applicability, add new aircraft types, or introduce unrelated requirements."},"complexity_factors":["Multiple alternative service documents referenced (HN-230.1, DN-177.1, EN-68.1, FN-55.1) requiring cross-checking against aircraft model","Dual compliance timelines (daily inspections vs. 100-hour/1 March 1991 deadline)","Specific part number and serial number ranges requiring careful verification against aircraft records","Conditional pilot-authorisation for daily inspections with specific certification requirements","Amendment structure (Amdt 1) updating original directive with revised documentation references"],"plain_english_summary":"This mandatory CASA Airworthiness Directive targets certain McDonnell Douglas (Hughes) and Kawasaki 369-series helicopters with specified tail-rotor blades. It requires daily pre-flight visual checks and a more detailed inspection/repair within 100 flight hours or by 1 March 1991, to detect cracks or thin wall thickness in blade root fittings. It matters because a blade-root failure can cause loss of control. The AD must be recorded on the Maintenance Release, the AD number noted with daily checks, and a copy kept aboard the aircraft."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"Amdt 1 revises the reference service documents and records the issuing of the FAA AD in support; it does not expand the set of affected part numbers/serial ranges or add new mandated actions beyond the inspections and corrective action already required (see 'Requirement' and final paragraph stating purpose of Amdt 1)."},"complexity_factors":["Technical specificity: applies only to particular part numbers and serial-number ranges (Applicability table).","Multiple referenced service documents (HN-230.1, DN-177.1, EN-68.1, FN-55.1) that contain the inspection and corrective procedures (Requirement).","Dual compliance timing: daily pre-flight inspection and a separate 100‑hour or calendar deadline (Compliance).","Delegated inspection authority: daily visual inspection may be performed by the pilot in command, with certification requirements (Note 1).","Record-keeping requirement: mandatory entry on the Maintenance Release and keeping a copy of the AD in the aircraft (Note 1).","Safety-critical consequence: failure of the root fitting is the hazardous event prompting the AD (Background).","Cross-reference to FAA AD (Note 2 and Amdt 1) increases reliance on foreign airworthiness material."],"plain_english_summary":"Requires daily and periodic visual inspections of specified tail-rotor blades on McDonnell Douglas (Hughes) and Kawasaki 369-series helicopters, and corrective action where the manufacturer’s service notices direct. The rule targets blades by part and serial number ranges to find cracks or reduced wall thickness in the blade root fitting after a reported failure; it affects aircraft operators, pilots (who may do the daily check), and maintenance organisations responsible for recording and carrying out repairs."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-83-amdt-1-tail-rotor-blades","history":"/api/acts/ad-hu-369-83-amdt-1-tail-rotor-blades/history","analysis":"/api/acts/ad-hu-369-83-amdt-1-tail-rotor-blades/analysis","conflicts":"/api/acts/ad-hu-369-83-amdt-1-tail-rotor-blades/conflicts","importantCases":"/api/acts/ad-hu-369-83-amdt-1-tail-rotor-blades/important-cases","documents":"/api/acts/ad-hu-369-83-amdt-1-tail-rotor-blades/documents"}}