{"id":"F2006B10675","name":"AD/HU 369/12 - Metal Tail Rotor Blades - Inspection","slug":"ad-hu-369-12-metal-tail-rotor-blades-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116614,"registerId":"commonwealth-F2006B10675-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/12 - Metal Tail Rotor Blades - Inspection","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)  McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\n \n\nAD/HU 369/12 Metal Tail Rotor Blades - Inspection 5/74\n\nApplicability: All model 369H series fitted with P/N 369A1613-3 metal tail rotor blades. Document:              Hughes SIN No. HN-65.\n\nCompliance: Before 31 May 1974.\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\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, time-bound safety directive from 1974. It has not expanded beyond its original narrow purpose of mandating a specific inspection on specific helicopter models. The scope remains precisely limited to the tail rotor blade issue identified in Hughes Service Information Notice HN-65."},"complexity_factors":["Extremely short document — only 8 substantive lines","No defined terms section — relies on external technical document (Hughes SIN HN-65) for actual inspection procedures","Simple binary applicability test: 'All model 369H series fitted with P/N 369A1613-3 metal tail rotor blades'","Single unconditional compliance requirement with fixed calendar date","No cross-references to other legislation beyond parent regulation (Part 39)","No exceptions, exemptions, or conditional logic"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific Hughes/Kawasaki 369 series helicopters to inspect their **metal tail rotor blades** (part number 369A1613-3) for defects.\n\n**Who it affects:** Anyone operating **Model 369H series helicopters** fitted with these specific metal tail rotor blades.\n\n**Why it matters:** Tail rotor blade failures can cause catastrophic loss of control. This directive was issued to prevent accidents by ensuring critical components are checked before a deadline.\n\n**Key details:**\n- **Compliance deadline:** Before 31 May 1974\n- **Technical reference:** Hughes Service Information Notice HN-65 (this document contains the actual inspection instructions)\n- **Legal force:** Non-compliance is an offence under aviation law — these blades cannot legally fly until inspected"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The provided text is the original directive language setting applicability (model 369H with P/N 369A1613-3), the required reference document (Hughes SIN No. HN-65), and a firm compliance deadline (Before 31 May 1974). There is no indication within the supplied text that the scope has been altered from the instrument as written."},"complexity_factors":["Very narrow applicability (single helicopter model series and single part number). (Applicability)","Single, time-limited action (one inspection deadline). (Compliance)","Reference to an external technical document (Hughes SIN No. HN-65) for the detailed procedure, which requires operators to obtain and follow that document. (Document)","No detailed procedural, enforcement, or exemption text included here—compliance mechanics beyond the reference are delegated to the manufacturer/regulator.","Historic fixed deadline (date in 1974) means the instrument is time-specific rather than establishing an ongoing inspection regime. (Compliance)"],"plain_english_summary":"- What this instrument does mechanically:\n  - It requires an inspection of the metal tail rotor blades on a specific set of helicopters. The directive applies to \"All model 369H series fitted with P/N 369A1613-3 metal tail rotor blades.\" (Applicability).\n  - The inspection must be carried out in accordance with the manufacturer document cited: \"Hughes SIN No. HN-65.\" (Document).\n  - The inspection must be completed by the stated deadline: \"Before 31 May 1974.\" (Compliance).\n\n- Who it affects:\n  - Owners and operators of McDonnell Douglas (Hughes) and Kawasaki 369 series helicopters of model 369H that have the specified part-numbered metal tail rotor blades. Maintenance organisations that service those helicopters will also be directly affected because they must carry out the inspection in line with the specified Hughes service instruction.\n\n- Why it matters (official claim and practical implications):\n  - The title of the directive is \"Metal Tail Rotor Blades - Inspection,\" which presents the official purpose-claim that an inspection of those blades is required. The instrument itself does not set out additional factual findings or the technical reason for the inspection; it specifies who must inspect, which document to follow, and the compliance deadline (Applicability; Document; Compliance).\n  - Practical implications and trade-offs to note (grounded in the text):\n    - Compliance burden: The directive creates a one-off compliance obligation with a firm due date (Compliance). The operator pays for the inspection work, any parts, and any follow-up maintenance or replacement discovered by that inspection. That cost is borne by the affected operators and their maintenance providers (Applicability; Document).\n    - Operational impact: Because the inspection has a deadline, operators must schedule the work before that date; this may require taking aircraft temporarily out of service to perform the inspection and any remedial work found. The text itself sets the deadline but does not describe allowances for continued operation pending inspection (Compliance).\n    - Delegation of technical method: The directive references a manufacturer service instruction (Hughes SIN No. HN-65) as the means to carry out the inspection (Document). That delegates the detailed technical steps to the manufacturer’s published procedure rather than setting them out in the directive itself; operators must obtain and follow that document to comply.\n    - Enforcement and discretion: The directive prescribes the action and deadline but the text supplied does not include information on enforcement mechanisms, acceptable evidence of compliance, or any exceptions. Where discretion or additional administrative detail exists would be determined by the issuing regulator or the referenced Hughes instruction, neither of which is contained in this text (Applicability; Document; Compliance).\n    - Distribution of effects: The directive’s requirements are narrowly targeted (single model series and a single blade part number), creating concentrated compliance obligations for the subset of owners/operators who have that part fitted and little or no direct cost to operators of other types (Applicability).\n\n- Summary statement of mechanics, incentives and likely consequences:\n  - Operators of affected 369H helicopters must arrange and fund an inspection of the specified metal tail rotor blades by the stated date, following the procedures in Hughes SIN HN-65. The regulator sets the who, what, and when; the manufacturer document provides the how. The instrument shifts technical compliance to following the manufacturer’s instruction and imposes a time-constrained operational and cost burden on the identified owners/operators (Applicability; Document; Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-12-metal-tail-rotor-blades-inspection","history":"/api/acts/ad-hu-369-12-metal-tail-rotor-blades-inspection/history","analysis":"/api/acts/ad-hu-369-12-metal-tail-rotor-blades-inspection/analysis","conflicts":"/api/acts/ad-hu-369-12-metal-tail-rotor-blades-inspection/conflicts","importantCases":"/api/acts/ad-hu-369-12-metal-tail-rotor-blades-inspection/important-cases","documents":"/api/acts/ad-hu-369-12-metal-tail-rotor-blades-inspection/documents"}}