{"id":"F2007L00700","name":"AD/A109/56 - Exhaust Duct Clamps","slug":"ad-a109-56-exhaust-duct-clamps","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":64286,"registerId":"commonwealth-F2007L00700-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Agusta A109 Series Helicopters","sectionType":"division","heading":"Agusta A109 Series Helicopters","content":"### Agusta A109 Series Helicopters\n\n| AD/A109/56 | Exhaust Duct Clamps | 4/2007 |\n| ---------- | ------------------- | ------ |\n\n| Applicability: | Agusta A109A, A109AII and A109C helicopters.                                                                                                                                                                                                                                                                                          |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Inspect the exhaust duct grooved clamps Part Number (P/N) 4606AC in accordance with Agusta “Bollettino Tecnico” 109-123 original issue or later approved revision.2. If cracks and/or corrosion are found replace the affected clamp.Note: EASA AD 2007-0041 dated 21 February 2007 refers.                                        |\n| Compliance:    | 1. Within 50 flight hours after the effective date of this AD and not later than12 May 2007, thereafter at intervals not to exceed 300 flight hours or yearly whichever occurs first.2. Before further flight after the effective date of this AD.                                                                                    |\n|                | This Airworthiness Directive becomes effective on 12 April 2007.                                                                                                                                                                                                                                                                      |\n| Background:    | A failure of the grooved clamp led to the loss of the exhaust duct. The duct subsequently stuck and caused failure of the tail rotor. This led to an emergency landing of the helicopter. This AD requires a repeated visual inspection of the exhaust duct clamps for cracking and corrosion to prevent such a failure re-occurring. |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n28 February 2007","sortOrder":0},{"sectionNumber":"AD/A109/56","sectionType":"part","heading":"AD/A109/56","content":"## AD/A109/56","sortOrder":1},{"sectionNumber":"Exhaust Duct Clamps","sectionType":"part","heading":"Exhaust Duct Clamps","content":"## Exhaust Duct Clamps","sortOrder":2},{"sectionNumber":"4/2007","sectionType":"part","heading":"4/2007","content":"## 4/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD’s scope—inspect and replace a specified clamp on listed A109 variants to prevent exhaust‑duct loss—matches the stated incident‑response purpose and does not expand beyond that stated safety objective in the instrument."},"complexity_factors":["Narrow applicability: only Agusta A109A, A109AII and A109C models","Single, identified component: grooved clamp P/N 4606AC","Clear, discrete actions: visual inspection and replace if cracks/corrosion","Defined timing: initial 50 flight‑hour window (with calendar date) then 300 flight‑hour or annual intervals","Reliance on an external technical bulletin (Agusta Bollettino Tecnico 109‑123) for inspection procedure","Safety‑critical consequence motivates short compliance window and ongoing recurrence risk"],"plain_english_summary":"The directive requires owners/operators of Agusta A109A, A109AII and A109C helicopters to inspect exhaust duct grooved clamps (P/N 4606AC) per Agusta Bollettino Tecnico 109‑123 within 50 flight hours (or by 12 May 2007), and then every 300 flight hours or yearly, replacing any clamp with cracks or corrosion. It takes effect 12 April 2007.\n\nThis imposes inspection and replacement costs and downtime on operators and maintenance organisations. The stated purpose is to prevent recurrence of an incident where a clamp failure caused loss of the exhaust duct and subsequent tail‑rotor malfunction."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical failure mode in specific helicopter models. The directive remains tightly focused on exhaust duct clamp inspection and replacement, exactly as intended when issued."},"complexity_factors":["Very short document (approximately 250 words)","Only 3 defined/model variants (A109A, A109AII, A109C)","Single specific part number referenced (P/N 4606AC)","Simple two-step requirement structure (inspect, then replace if needed)","Clear compliance timeline with specific dates and flight hours","No nested exceptions or conditional logic","Minimal cross-referencing (only one external document: EASA AD 2007-0041)","Straightforward cause-and-effect background explanation"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of Agusta A109A, A109AII and A109C helicopters in Australia to inspect exhaust-duct clamps for cracks/corrosion and to replace any defective clamps immediately. It follows an incident where a failed clamp let an exhaust duct detach and destroy the tail rotor, forcing an emergency landing.\n\nInspections are required promptly (initially within a short flight‑hour window) and at regular intervals; compliance is mandatory for continued airworthiness."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a109-56-exhaust-duct-clamps","history":"/api/acts/ad-a109-56-exhaust-duct-clamps/history","analysis":"/api/acts/ad-a109-56-exhaust-duct-clamps/analysis","conflicts":"/api/acts/ad-a109-56-exhaust-duct-clamps/conflicts","importantCases":"/api/acts/ad-a109-56-exhaust-duct-clamps/important-cases","documents":"/api/acts/ad-a109-56-exhaust-duct-clamps/documents"}}