{"id":"F2008L02520","name":"AD/EMB-145/11 - APU Firewall","slug":"ad-emb-145-11-apu-firewall","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74489,"registerId":"commonwealth-F2008L02520-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-145/11 | APU Firewall | 8/2008 |\n| ------------- | ------------ | ------ |\n\n| Applicability: | Model EMB-145 aircraft, serial numbers 145004 through 145019.                                                                                                                                                                                                                                                                   |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Inspect the APU firewall for cracks in accordance with Part I of EMBRAER Service Bulletin No. 145-53-0004, or later CTA/ANA approved revision.Note: Installation of the vibration damper in accordance with Part II of the Requirement document constitutes terminating action to the inspection requirement of this Directive. |\n| Compliance:    | At intervals not to exceed 100 flight hours; until Part II of the Requirement document is accomplished.                                                                                                                                                                                                                         |\n|                | This Airworthiness Directive becomes effective on 31 July 2008.                                                                                                                                                                                                                                                                 |\n| Background:    | Reports were received of cracks in the shell spot welded area of EMB-145 aircraft APU firewalls. Undetected cracking could affect the structural integrity and sealing function of the firewall.                                                                                                                                |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n17 June 2008","sortOrder":0},{"sectionNumber":"AD/EMB-145/11","sectionType":"part","heading":"AD/EMB-145/11","content":"## AD/EMB-145/11","sortOrder":1},{"sectionNumber":"APU Firewall","sectionType":"part","heading":"APU Firewall","content":"## APU Firewall","sortOrder":2},{"sectionNumber":"8/2008","sectionType":"part","heading":"8/2008","content":"## 8/2008","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific airworthiness concern on a limited fleet of aircraft. It has not expanded beyond its original purpose of ensuring APU firewall integrity on affected Embraer models."},"complexity_factors":["Single, specific mechanical issue (APU firewall cracks)","Clear applicability limited to 16 specific aircraft serial numbers","Simple binary compliance path: recurring inspections OR one-time terminating action","Only one defined technical reference (EMBRAER Service Bulletin No. 145-53-0004)","No nested exceptions, conditional clauses, or cross-references to other legislation","Straightforward time-based compliance interval (100 flight hours)"],"plain_english_summary":"This AD requires operators of Embraer EMB-145 jets (S/N 145004–145019) to inspect the APU firewall for cracks every 100 flight hours after cracks were found in welded areas that could allow fire spread. Operators may instead install a specified vibration damper as a terminating action for the recurring inspections. The directive is mandatory in Australia and has applied since 31 July 2008."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument's scope remains as stated: mandatory inspections of APU firewalls on EMB-145 serials 145004–145019 at intervals not exceeding 100 flight hours, with the inspection requirement terminated only by completing the Part II modification (vibration damper) per the referenced service bulletin (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow applicability to a small set of airframes (serial numbers 145004–145019) — limits scale but concentrates compliance on specific operators (Applicability).","Recurring inspection obligation at short intervals (every 100 flight hours) until terminating action is taken — increases operational and maintenance scheduling burden (Compliance).","A clear terminating action exists (installation of vibration damper per Part II of EMBRAER Service Bulletin) but requires following a specific service document or an approved later revision (Requirement / Note).","Directive references operator compliance with EMBRAER Service Bulletin No. 145-53-0004 or later CTA/ANA approved revision, introducing dependency on manufacturer documentation and regulator-approved revisions (Requirement).","Enforcement and effective date set by the Civil Aviation Safety Authority (becomes effective 31 July 2008; signed by CSA delegate) — creates a fixed compliance start and regulator oversight (Compliance / signature)."],"plain_english_summary":"Mandates operators of EMB-145 aircraft (serials 145004–145019) to inspect the APU firewall for cracks every 100 flight hours until a specified modification (installation of a vibration damper per EMBRAER Service Bulletin) is completed. The Civil Aviation Safety Authority enforces the directive; operators bear inspection and modification costs. The measure responds to reported shell spot-weld cracking that could compromise firewall integrity and sealing."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-145-11-apu-firewall","history":"/api/acts/ad-emb-145-11-apu-firewall/history","analysis":"/api/acts/ad-emb-145-11-apu-firewall/analysis","conflicts":"/api/acts/ad-emb-145-11-apu-firewall/conflicts","importantCases":"/api/acts/ad-emb-145-11-apu-firewall/important-cases","documents":"/api/acts/ad-emb-145-11-apu-firewall/documents"}}