{"id":"F2008L03692","name":"AD/EMB-120/45 Amdt 1 - Stall Warning Computer","slug":"ad-emb-120-45-amdt-1-stall-warning-computer","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":75398,"registerId":"commonwealth-F2008L03692-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Embraer EMB-120 (Brasilia) Series Aeropl","sectionType":"division","heading":"Embraer EMB-120 (Brasilia) Series Aeroplanes","content":"### Embraer EMB-120 (Brasilia) Series Aeroplanes\n\n| AD/EMB-120/45 Amdt 1 | Stall Warning Computer | 11/2008 |\n| -------------------- | ---------------------- | ------- |\n\n| Applicability: | All EMB-120( ) model aeroplanes.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. Replace the current stall warning computers with new improved versions in accordance with detailed instructions and procedures described in Embraer Service Bulletin (SB) 120-27-0092 Revision 01 dated 29 December 2006, or later revision approved by Brazilian Agência Nacional de Avição Civil (ANAC).                                                                                                                                                                                                            |\n|                | Note 1: Before installing the improved stall warning computers, the detailed instructions and procedures described in the Embraer SB No. 120-27-0091Revision 02 dated 29 September 2003, or later revisions approved by ANAC must be accomplished.                                                                                                                                                                                                                                                                       |\n|                | 2. EMB-120( ) aircraft may not be operated with stall warning computers bearing part number (P/N) C-81806-1 Mod. A, C-81806-2 Mod. A or C-81806-3 installed.                                                                                                                                                                                                                                                                                                                                                             |\n|                | Note 2: ANAC AD 2007-03-03 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| Compliance:    | For Requirement 1 - Remains unchanged as “Within the next 36 calendar months after the effective date of the original issue of this Directive (7 June 2007)”.                                                                                                                                                                                                                                                                                                                                                            |\n|                | For Requirement 2 - After 7 June 2010.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Amendment becomes effective on 23 October 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| Background:    | Icing tunnel tests on an EMB-120 wing section, conducted under a joint Embraer-NASA-FAA-CTA research program well after the EMB-120( ) was type-certificated, have shown that stick shaker to stick pusher speed margins may drop below the minimum required by the applicable regulations in certain icing conditions. Although flight tests have shown that the aircraft handling qualities are not adversely affected, these reduced speed margins may significantly increase crew workload in certain flight phases. |\n|                | Since this condition affects flight safety, the original issue of this Directive required the replacement of the stall warning computers.                                                                                                                                                                                                                                                                                                                                                                                |\n\n|     | This Amendment continues the requirements of the original issue but extends the compliance for Requirement 2 by 28 days to align with the Requirement 1 compliance date. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n|     | The original issue of this Directive became effective on 7 June 2007.                                                                                                    |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n11 September 2008","sortOrder":0},{"sectionNumber":"AD/EMB-120/45 Amdt 1","sectionType":"part","heading":"AD/EMB-120/45 Amdt 1","content":"## AD/EMB-120/45 Amdt 1","sortOrder":1},{"sectionNumber":"Stall Warning Computer","sectionType":"part","heading":"Stall Warning Computer","content":"## Stall Warning Computer","sortOrder":2},{"sectionNumber":"11/2008","sectionType":"part","heading":"11/2008","content":"## 11/2008","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"The amendment does not alter the substantive mandate to replace stall‑warning computers or the ban on specified part numbers; it only extends/aligns the compliance timing by 28 days for Requirement 2 to match Requirement 1. No additional aircraft types or new technical requirements were added."},"complexity_factors":["Safety‑critical technical subject matter (stall warning systems and stall protection behaviour in icing).","Dependence on external technical documents: Embraer Service Bulletins 120‑27‑0092 and prerequisite SB 120‑27‑0091, including later revisions only if approved by ANAC.","Multiple, staggered compliance dates and a narrow timing amendment (Requirement 1: within 36 months from original directive date; Requirement 2: effective after 7 June 2010; amendment aligns dates).","Direct prohibition of specific part numbers (P/N C‑81806‑1 Mod A, C‑81806‑2 Mod A, C‑81806‑3) with operational ban after a cut‑off date.","Interagency references and approvals: Embraer (manufacturer), ANAC (Brazilian authority) approvals referenced, and enforcement by CASA/Delegate.","Operational burden on operators: procurement, installation, downtime and certification to SB procedures before installation.","Cross‑references to prior airworthiness directives (ANAC AD 2007‑03‑03) increasing traceability requirements.","Limited substantive change by the amendment (a deadline alignment) but administrative implications for scheduling fleet modifications."],"plain_english_summary":"This amendment requires all Embraer EMB‑120 aircraft to have their stall‑warning computers replaced with Embraer’s improved units (per Embraer Service Bulletin 120‑27‑0092) and forbids operating aircraft fitted with specified stall warning computer part numbers (P/N C‑81806‑1/2/3 Mod A). It responds to research showing reduced stick‑shaker to stick‑pusher speed margins in certain icing conditions. Operators must follow Embraer SB procedures and obtain ANAC‑approved revisions; operators pay for parts/installation and must meet the stated compliance dates enforced by the aviation safety regulator."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of the Airworthiness Directive. The sole change is a minor technical adjustment to the compliance date for Requirement 2 (extending by 28 days to align with Requirement 1). The safety objective, affected aircraft, and mandatory actions remain identical to the original 2007 directive."},"complexity_factors":["Short, single-purpose document (2 requirements only)","Minimal defined terms (only standard aviation abbreviations like P/N for part number, SB for Service Bulletin)","Simple conditional structure: Requirement 1 (action required) + Requirement 2 (prohibition)","Cross-references limited to one external Brazilian aviation directive (ANAC AD 2007-03-03) and specific Embraer service bulletins","Clear compliance dates with straightforward timeline calculations","No nested exceptions or complex conditional logic"],"plain_english_summary":"This CASA Airworthiness Directive requires Australian operators of Embraer EMB‑120 aircraft to replace certain stall warning computers with improved units because original models can reduce the safe margin between stick shaker and stick pusher in icing, increasing pilot workload and risk. The Amendment grants operators an additional 28 days before it becomes illegal to operate with the old computer models."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-120-45-amdt-1-stall-warning-computer","history":"/api/acts/ad-emb-120-45-amdt-1-stall-warning-computer/history","analysis":"/api/acts/ad-emb-120-45-amdt-1-stall-warning-computer/analysis","conflicts":"/api/acts/ad-emb-120-45-amdt-1-stall-warning-computer/conflicts","importantCases":"/api/acts/ad-emb-120-45-amdt-1-stall-warning-computer/important-cases","documents":"/api/acts/ad-emb-120-45-amdt-1-stall-warning-computer/documents"}}