{"id":"F2008L02862","name":"AD/EMB-145/21 - Engine Anti-Ice Valve","slug":"ad-emb-145-21-engine-anti-ice-valve","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74746,"registerId":"commonwealth-F2008L02862-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Embraer EMB-135 and EMB-145 Series Aerop","sectionType":"division","heading":"Embraer EMB-135 and EMB-145 Series Aeroplanes","content":"### Embraer EMB-135 and EMB-145 Series Aeroplanes\n\n| AD/EMB-145/21 | Engine Anti-Ice Valve | 9/2008 |\n| ------------- | --------------------- | ------ |\n\n| Applicability: | Embraer EMB-l45( ) aircraft, except aircraft of serial numbers 14500921, 14500928, 14500932, 14500949, 14500958, 14500971, 14500973 and up, which have in-factory modification incorporated.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Comply with the requirements of AGÊNCIA NACIONAL DE AVIAÇÃO CIVIL - BRAZIL AD 2006-09-03R1.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| Compliance:    | As detailed in AGÊNCIA NACIONAL DE AVIAÇÃO CIVIL - BRAZIL AD2006-09-03R1 with a revised effective date of 28 August 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n|                | This Airworthiness Directive becomes effective on 28 August 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n| Background:    | There has been occurrence of an engine anti-ice system valve failure, where the valve spring seat had broken and obstructed the anti-ice system venturi tube. Aircraft dispatch with that failure may be allowed by the operator Minimum Equipment List (MEL), since the engine anti-ice system valve be locked in the OPEN position.However, there is no readily available means to make sure the anti-ice system tubing is free of debris, allowing unrestricted hot airflow to the piccolo tube on the engine inlet lip. Therefore, should the aircraft encounter icing conditions, ice may accrete in the engine inlet lip and be ingested through the air inlet, resulting in possible engine damage and flame-out. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n17 July 2008","sortOrder":0},{"sectionNumber":"AD/EMB-145/21","sectionType":"part","heading":"AD/EMB-145/21","content":"## AD/EMB-145/21","sortOrder":1},{"sectionNumber":"Engine Anti-Ice Valve","sectionType":"part","heading":"Engine Anti-Ice Valve","content":"## Engine Anti-Ice Valve","sortOrder":2},{"sectionNumber":"9/2008","sectionType":"part","heading":"9/2008","content":"## 9/2008","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive enforces the remedial measures set out in Brazil's ANAC AD to mitigate risk from anti‑ice valve spring‑seat debris; it does not expand or narrow that safety objective beyond excluding aircraft with a documented in‑factory modification. Operators and maintenance organisations bear the direct costs and compliance burden of inspections and repairs. The instrument relies on the referenced AD for technical procedures, requiring operators to obtain and apply that external document. Effective date provided: 28 August 2008."},"complexity_factors":["Direct cross‑reference to an external regulator's AD (ANAC AD 2006‑09‑03R1) — compliance requires obtaining and following another detailed document.","Applicability carved out by specific serial numbers that have an in‑factory modification, requiring serial‑number checks.","Safety‑critical technical work (inspection/clearing of anti‑ice valve and internal tubing) that may require access to confined/hidden components.","Interaction with operator Minimum Equipment List (MEL) practice — valve may be dispatchable when locked OPEN, creating an operational nuance.","Explicit effective/compliance date (28 August 2008) creates a fixed regulatory deadline for operators.","This AD itself delegates procedural detail to the referenced ANAC AD, increasing administrative burden to cross‑check documents."],"plain_english_summary":"This Airworthiness Directive requires operators of Embraer EMB‑135/145 series aeroplanes (except listed serial numbers with an in‑factory modification) to carry out the inspection and corrective actions set out in Brazil's ANAC AD 2006‑09‑03R1 (revised, effective 28 Aug 2008). Mechanically, it targets the engine anti‑ice valve and associated tubing to remove broken spring‑seat debris that can obstruct the venturi.\n\nIt affects aircraft owners and maintenance organisations, who must perform the inspections/repairs and bear the costs. The stated purpose is to prevent ice accretion and potential engine ingestion, damage or flame‑out."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a narrow, specific safety purpose. It addresses a particular mechanical failure mode in a specific aircraft type. There is no indication of scope creep; the document maintains its original intent of mandating repairs to prevent engine anti-ice system failures."},"complexity_factors":["Very short document (approximately 250 words)","Only 1 defined applicability exception (8 specific serial numbers)","Single cross-reference to Brazilian aviation authority directive (AD 2006-09-03R1)","No nested conditional logic or exceptions to exceptions","Straightforward compliance requirement: follow the Brazilian AD","Minimal legislative structure — essentially a notice format rather than complex statutory text"],"plain_english_summary":"This Australian Airworthiness Directive requires operators of Embraer EMB‑145 jets (except eight serial numbers already factory‑modified) to comply with a Brazilian AD fixing the engine anti‑ice valve.  \n\nA broken spring seat can shed debris that blocks tubing and, in icing conditions, allow ice to form and enter the engine—risking engine damage or flame‑out. The AD closes this safety gap by mandating the prescribed repair/inspection."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-145-21-engine-anti-ice-valve","history":"/api/acts/ad-emb-145-21-engine-anti-ice-valve/history","analysis":"/api/acts/ad-emb-145-21-engine-anti-ice-valve/analysis","conflicts":"/api/acts/ad-emb-145-21-engine-anti-ice-valve/conflicts","importantCases":"/api/acts/ad-emb-145-21-engine-anti-ice-valve/important-cases","documents":"/api/acts/ad-emb-145-21-engine-anti-ice-valve/documents"}}