{"id":"F2009L00293","name":"AD/HU 369/108 Amdt 3 - Tailboom Attachment","slug":"ad-hu-369-108-amdt-3-tailboom-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76829,"registerId":"commonwealth-F2009L00293-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 369/108 Amdt 3 | Tailboom Attachment | 2/2009 |\n| -------------------- | ------------------- | ------ |\n\n| Applicability: | Model 600N helicopters, serial numbers with a prefix “RN” and 003 through 058, that have not been modified in the fuselage aft section to strengthen the tailboom attachments and longerons in accordance with MD Helicopters Technical Bulletins TB600N-007, TB600N-007R1, or TB600N-007R2, or a later FAA approved revision.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2008-20-05Amdt 39-15684.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Compliance:    | As specified in the Requirement document.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n|                | This Amendment becomes effective on 12 February 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Background:    | The FAA received a report of a cracked tailboom attachment bolt on an MD 600N helicopter. Further inspection revealed cracking on bolts and attachments on several other helicopters. This condition, if not corrected, could result in failure of a tailboom attachment, loss of the tailboom, and subsequent loss of control of the helicopter.Amendment 1 required the same actions as the original issue of this Directive, but also required additional inspection holes in the aft fuselage skin panels and inspection of the upper and lower tailboom attachment fittings, the upper longerons, and the angles and nutplates for cracks. It also required eventual replacement of the upper right tailboom attachment fitting.Amendment 2 required modification of the fuselage aft section to strengthen the tailboom attachment fittings and upper longerons. |\n\n|     | Amendment 3 is issued in response to a new FAA AD, which requires modifying the fuselage aft section, repetitively inspecting the tailboom attachment fittings, installing inspection holes and attachment bolt washers, modifying both access covers, and replacing broken attachment bolts. |\n| --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n5 December 2008","sortOrder":0},{"sectionNumber":"AD/HU 369/108 Amdt 3","sectionType":"part","heading":"AD/HU 369/108 Amdt 3","content":"## AD/HU 369/108 Amdt 3","sortOrder":1},{"sectionNumber":"Tailboom Attachment","sectionType":"part","heading":"Tailboom Attachment","content":"## Tailboom Attachment","sortOrder":2},{"sectionNumber":"2/2009","sectionType":"part","heading":"2/2009","content":"## 2/2009","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":6,"scope_assessment":{"changed":true,"description":"Yes. The directive expanded across amendments: the original action focused on inspections; Amendment 1 added inspection holes and extended fittings and longerons inspections; Amendment 2 required modification of the fuselage aft section to strengthen tailboom attachments and upper longerons; Amendment 3 further requires modifying the fuselage aft section, repetitive inspections of tailboom attachment fittings, installing inspection holes and attachment-bolt washers, modifying both access covers, and replacing broken attachment bolts. The scope therefore moved from inspection-focused to mandatory structural modification plus ongoing inspection obligations."},"complexity_factors":["Narrow, serial-numbered applicability (Model 600N, RN003–RN058) requiring accurate operator records.","Cross-reference to an external FAA AD (FAA AD 2008-20-05) and MD Technical Bulletins (TB600N-007 series) for technical details; compliance depends on those documents.","Cumulative amendment history (original AD + Amendments 1–3) with layered requirements (inspections, added inspection holes, fittings inspection, structural strengthening).","Mixture of one-off structural modifications (fuselage aft strengthening) and repetitive inspection obligations, increasing implementation and maintenance burden.","Multiple discrete tasks: installing inspection holes and washers, modifying access covers, replacing bolts — each carrying parts, labour and possible downtime costs.","Compliance wording ties timing and methods to the Requirement document rather than restating procedures, creating procedural dependence on external documents."],"plain_english_summary":"Requires operators of MD/Kawasaki 369 Model 600N helicopters (serials RN003–RN058 not already modified per MD TB600N-007 series) to comply with FAA AD 2008-20-05. Actions include modifying the aft fuselage to strengthen tailboom attachments, repetitive inspections of attachment fittings, installing inspection holes and bolt washers, altering access covers, and replacing broken attachment bolts. It addresses reported cracked tailboom attachment bolts that could cause tailboom separation and loss of control."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 3 to an existing Airworthiness Directive. The document explicitly states it is issued in response to a new FAA AD and continues the same safety purpose as the original directive (addressing tailboom attachment integrity). The amendments have progressively expanded the required actions (from initial inspections in the original, to additional inspection holes in Amendment 1, to structural modifications in Amendment 2, and now to additional modifications and repetitive inspections in Amendment 3), but this represents iterative strengthening of the same safety measure rather than scope creep beyond the original purpose."},"complexity_factors":["Short, single-purpose document (approximately 300 words)","Only 4 defined elements: applicability criteria, requirement reference, compliance date, and background","Heavy reliance on external reference (FAA AD 2008-20-05) — the actual technical requirements are not reproduced in this document","Simple conditional logic: applies to specific serial numbers AND only if not already modified per specific technical bulletins","No nested exceptions or cross-references to other Australian legislation","Clear structure with standard AD format (Applicability, Requirement, Compliance, Background)"],"plain_english_summary":"This CASA Airworthiness Directive mandates safety modifications and repeated inspections of the tailboom attachment on MD 600N helicopters after the FAA found cracked attachment bolts that could lead to tailboom separation and loss of control.  \n\nIt applies to RN-series and serials 003–058 unless already strengthened per TB600N‑007, requires compliance with FAA AD 2008‑20‑05, and took effect 12 February 2009."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-108-amdt-3-tailboom-attachment","history":"/api/acts/ad-hu-369-108-amdt-3-tailboom-attachment/history","analysis":"/api/acts/ad-hu-369-108-amdt-3-tailboom-attachment/analysis","conflicts":"/api/acts/ad-hu-369-108-amdt-3-tailboom-attachment/conflicts","importantCases":"/api/acts/ad-hu-369-108-amdt-3-tailboom-attachment/important-cases","documents":"/api/acts/ad-hu-369-108-amdt-3-tailboom-attachment/documents"}}