{"id":"F2007L04357","name":"AD/HU 369/119 - Tail Rotor Blade Root Fitting - 2","slug":"ad-hu-369-119-tail-rotor-blade-root-fitting-2","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70652,"registerId":"commonwealth-F2007L04357-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"McDonnell Douglas (Hughes) and Kawasaki ","sectionType":"division","heading":"McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters","content":"### McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\n| AD/HU 369/119 | Tail Rotor Blade Root Fitting - 2 | 1/2008 DM |\n| ------------- | --------------------------------- | --------- |\n\n| Applicability: | Kawasaki Model 369HS and 369D helicopters, equipped with a tail rotor blade part number 369A1613, all dash numbers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Inspect each affected tail rotor blade for a smooth radius as follows:a. Remove the tail rotor blade assembly in accordance with paragraphs 9.(1) through 9.(3), of Kawasaki Service Bulletins No. KSB-369-339 orKSB-369D-235, both dated 7 May 2007, as applicable; or later JCAB approved revision.b. Using a bright light, inspect the bore of the tail rotor blade root fitting in accordance with paragraph 9.(4) and Figure 2 of the applicable service bulletin.c. Before further flight, replace each blade assembly that does not have a smooth radius in accordance with paragraph 9.(4) b. of the applicable service bulletin.d. Identify the serviceable tail rotor blade assembly with the applicable model of helicopter in accordance with paragraph 9.(5) and Figure 3 of the applicable service bulletin.Note 1: Special Flight permits will not be allowed.Note 2: JCAB AD TCD-7098-2007 refers. |\n| Compliance:    | Unless already accomplished, before further flight after 14 November 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n|                | This Airworthiness Directive becomes effective on 14 November 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Background:    | The JCAB received a report of an accident after the loss of a tail rotor blade. This condition, if not corrected, could result in the failure of a tail rotor blade and subsequent loss of control of the helicopter.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n12 November 2007","sortOrder":0},{"sectionNumber":"AD/HU 369/119","sectionType":"part","heading":"AD/HU 369/119","content":"## AD/HU 369/119","sortOrder":1},{"sectionNumber":"Tail Rotor Blade Root Fitting - 2","sectionType":"part","heading":"Tail Rotor Blade Root Fitting - 2","content":"## Tail Rotor Blade Root Fitting - 2","sortOrder":2},{"sectionNumber":"1/2008 DM","sectionType":"part","heading":"1/2008 DM","content":"## 1/2008 DM","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD is narrowly targeted to address a specific unsafe condition: possible failure of the tail rotor blade root fitting on Kawasaki 369HS and 369D helicopters with blade P/N 369A1613. The instrument confines remedies to inspection and replacement procedures set out in the Kawasaki service bulletins (or later JCAB-approved revisions) and does not expand obligations beyond that technical corrective action. It therefore does not appear to have grown beyond its original safety-focused purpose."},"complexity_factors":["Narrow applicability to two helicopter models and a single blade part number (369A1613).","Cross-reference to two Kawasaki service bulletins (KSB-369-339 and KSB-369D-235) and any later JCAB-approved revisions (dependency on external documents).","Instruction to follow specific subparagraphs of the service bulletins (paragraphs 9.(1)–9.(5)) — procedural cross-references rather than full text in the AD.","Binary inspection criterion (presence of a \"smooth radius\") which is simple to state but requires subjective assessment by maintenance staff under bright-light inspection.","Mandatory removal of the blade assembly, inspection, replacement if defective, and marking/identification steps — multiple discrete actions. ","Prohibition on special flight permits (administrative restriction) and a fixed compliance trigger date (before further flight after 14 November 2007).","Reference to a foreign regulator's AD (JCAB TCD-7098-2007), adding an additional regulatory cross-check."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires operators of Kawasaki Model 369HS and 369D helicopters that have tail rotor blades with part number 369A1613 to remove each affected tail rotor blade assembly and inspect the bore of the blade root fitting for a smooth radius. (See \"Requirement\".)\n- The removal and inspection must be done in accordance with specific steps in Kawasaki Service Bulletins KSB-369-339 or KSB-369D-235 (both dated 7 May 2007), or any later revision approved by the Japanese Civil Aviation Bureau (JCAB). The AD cites paragraphs 9.(1)–9.(5) of the applicable service bulletin for the detailed procedures.\n- If the blade root fitting does not have a smooth radius, the blade assembly must be replaced before the helicopter is flown again. The replacement and identification/marking of the serviceable blade must follow the service bulletin instructions. (Requirement items b–d.)\n- Special flight permits to ferry the helicopter for compliance are not allowed. The AD became effective on 14 November 2007 and requires compliance before the next flight after that date if not already done. (Compliance and Note 1.)\n\n**Who this affects**\n\n- Owners/operators and maintenance organisations responsible for Kawasaki Model 369HS and 369D helicopters fitted with tail rotor blade P/N 369A1613.  \n- Maintenance personnel who must follow the Kawasaki service bulletin procedures or any later JCAB-approved revision.  \n- Parts suppliers/manufacturers who supply replacement tail rotor blades for these helicopter models.\n\n**Why it matters (stated purpose and safety concern)**\n\n- The stated reason (Background) is a reported accident involving loss of a tail rotor blade. The AD says the condition (an improper radius at the blade root fitting) could lead to blade failure and subsequent loss of control of the helicopter.\n\n**Operational consequences, costs, and who decides**\n\n- Who pays: the helicopter owner/operator pays for removal, inspection, any required replacement parts, and maintenance labour.  \n- Who decides: the operator/maintenance organisation decides when to schedule the work, subject to the legal requirement not to fly until compliance. The service bulletin (and any JCAB-approved revision) directs the technical steps.  \n- Behaviour change: operators must ground affected helicopters until inspection is complete and any defective blades are replaced. No special flight permit is permitted to ferry the aircraft for the work, which eliminates an option to move the helicopter pending compliance.\n\n**Implementation and compliance risks**\n\n- Dependence on external documents: the AD cross-references Kawasaki service bulletins and any later JCAB-approved revisions, so compliance requires access to and correct interpretation of those documents (paragraph 9 references).  \n- Parts availability: if replacement blades are required, lead times or limited stock could extend helicopter downtime and increase costs.  \n- Maintenance burden: the AD requires removal of the blade assembly and a detailed inspection (bright-light inspection of the bore and verification of a smooth radius). That is routine for maintenance organisations but imposes labour and scheduling costs on small operators.  \n- Enforcement impact: prohibition on special flight permits means non-compliant helicopters cannot be legally flown even for delivery to a maintenance facility.\n\n**Market and competition effects (practical lens)**\n\n- Small commercial and private operators are most exposed to downtime and replacement costs.  \n- Maintenance providers performing the work may see short-term demand for inspections/replacements.  \n- The AD does not change ownership rules or create new fees; it imposes a mandatory safety action that can increase operating cost and reduce availability until corrected.\n\n**Trade-offs and opportunity costs**\n\n- The AD reduces the risk of in-flight tail-rotor blade failure by mandating inspection and replacement where required. That safety benefit comes with the cost of inspection time, potential parts replacement, and grounded aircraft time — borne by operators.  \n- The instrument narrows operator choices by disallowing special flight permits and by requiring conformity with manufacturer/JCAB procedures, which centralises the technical method for compliance.\n\n(References: Requirement, Compliance, Notes, Background sections; explicit cross‑references to Kawasaki Service Bulletins KSB-369-339 and KSB-369D-235 and JCAB AD TCD-7098-2007.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in specific helicopter models. The \"-2\" suffix indicates this is a revised or reissued directive, but it does not expand beyond the original safety purpose of preventing tail rotor blade failures."},"complexity_factors":["Single, discrete safety issue with clear mechanical remedy","Only 4 procedural steps (remove, inspect, replace if needed, mark as serviceable)","References external technical documents (Kawasaki Service Bulletins) but provides specific paragraph citations","No nested exceptions or conditional logic — universal application to affected fleet","Single compliance deadline with no phased implementation","Minimal defined terms (only 'applicable service bulletin' and specific part numbers)"],"plain_english_summary":"This AD orders owners/operators of Kawasaki Model 369HS and 369D helicopters with tail rotor blade P/N 369A1613 to remove and inspect the blade root bore for a smooth radius and replace any blade that fails inspection. Inspections must be done before further flight after 14 November 2007, with no special flight permits allowed.\n\nIt affects Australian operators (emergency services, agricultural users, private owners) and was issued after a reported accident because a missing radius can allow blade separation, causing loss of control and likely fatal crash."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-119-tail-rotor-blade-root-fitting-2","history":"/api/acts/ad-hu-369-119-tail-rotor-blade-root-fitting-2/history","analysis":"/api/acts/ad-hu-369-119-tail-rotor-blade-root-fitting-2/analysis","conflicts":"/api/acts/ad-hu-369-119-tail-rotor-blade-root-fitting-2/conflicts","importantCases":"/api/acts/ad-hu-369-119-tail-rotor-blade-root-fitting-2/important-cases","documents":"/api/acts/ad-hu-369-119-tail-rotor-blade-root-fitting-2/documents"}}