{"id":"F2008L02519","name":"AD/EMB-145/12 - APU Firewall - 2","slug":"ad-emb-145-12-apu-firewall-2","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74487,"registerId":"commonwealth-F2008L02519-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-145/12 | APU Firewall - 2 | 8/2008 |\n| ------------- | ---------------- | ------ |\n\n| Applicability: | Models EMB-145 and EMB-135 aircraft, serial numbers 145462, 145484, 145495, 145505, 145528, 145540, 145549, 145555, 145590, 145625, 145637, 145642 through 145646, 145649, 145650, 145654, 145655, 145657 through 145660, 145662, 145664, 145666, 145672, 145674, 145675, 145677, 145681, 145683, 145684, 145688 through 145690, 145683, and 145697.                                                                                                                                                                                                                                 |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Accomplish a detailed visual inspection of the APU firewall for cracks and structural integrity.If cracking is detected during any inspection, before further flight, repair in accordance with the limits and instructions of the applicable Structural Repair Manual (SRM); or,Replace the part number 145-47494-401 firewall with a part number 145-47494-607 firewall in accordance with Part II of EMBRAER Service Bulletin (SB) No.145-53-0037 or SB No. 145LEG-53-0010, as applicable; or later CTA/ANAC approved revision.Note: Brazil CTA AD 2003-07-02 Amdt 39-999 refers. |\n| Compliance:    | Inspect within 200 flight hours after 31 July 2008, and thereafter at intervals not to exceed 200 flight hours or 90 days, whichever occurs first; until replacement of the part number 145-47494-401 firewall with a part number 145-47494-607 firewall.                                                                                                                                                                                                                                                                                                                            |\n|                | This Airworthiness Directive becomes effective on 31 July 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| Background:    | Reports were received of cracking of the APU firewall. 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\n18 June 2008","sortOrder":0},{"sectionNumber":"AD/EMB-145/12","sectionType":"part","heading":"AD/EMB-145/12","content":"## AD/EMB-145/12","sortOrder":1},{"sectionNumber":"APU Firewall - 2","sectionType":"part","heading":"APU Firewall - 2","content":"## APU Firewall - 2","sortOrder":2},{"sectionNumber":"8/2008","sectionType":"part","heading":"8/2008","content":"## 8/2008","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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific airworthiness concern (APU firewall cracking) on specific aircraft. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Single, specific technical requirement (visual inspection of one component)","Limited applicability (41 specific aircraft serial numbers explicitly listed)","Clear compliance timeline (200 flight hours/90 days)","Straightforward conditional logic (if cracking found → repair or replace before flight)","No nested definitions or extensive cross-referencing to other legislation","Refers to external technical documents (Service Bulletins) but provides specific part numbers for clarity"],"plain_english_summary":"This mandatory Airworthiness Directive targets 41 specific Embraer EMB‑135/145 jets and requires owners/operators to inspect the APU firewall for cracks or structural damage. Aircraft with cracked firewalls must be grounded until repaired or fitted with an improved firewall.\n\nIt affects the listed operators and maintenance teams and is safety‑critical because a compromised firewall may fail to contain fire. Inspections repeat every 200 flight hours or 90 days until replacement."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies only to the listed EMB‑135/145 serial numbers and prescribes inspections plus repair or replacement to address reported APU firewall cracking. The text shows no alteration of that original, safety‑focused scope — it prescribes inspection intervals, acceptable repair method (SRM) and a replacement part via specified service bulletins (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Narrow, specific applicability to a discrete list of serial numbers (Applicability) — reduces regulatory reach but requires accurate fleet identification.","Recurring inspection schedule (every 200 flight hours or 90 days) creates ongoing operational and administrative burden for operators (Compliance).","Remedial options include either SRM repairs or full part replacement, introducing technical decision-making and potential cost trade-offs for operators (Requirement: 'repair in accordance with SRM' or 'replace... in accordance with... SB').","Mandatory conformity with Embraer Service Bulletins or later CTA/ANAC‑approved revisions ties compliance to external documents and regulator approvals (Requirement: reference to SB No.145-53-0037 / 145LEG-53-0010 and 'later CTA/ANAC approved revision').","Who pays: operators incur inspection, repair and replacement expenses (Requirement & Compliance).","Compliance timing and effective date are explicit (inspect within 200 flight hours after 31 July 2008; AD effective 31 July 2008), leaving little temporal discretion (Compliance / effective date).","Administrative detail in the serial number list (including a repeated entry) raises a small risk of clerical confusion when matching affected airframes (Applicability).","Safety rationale is narrow and technical (reports of cracking; Background), so legal interpretation centers on mechanical conformity rather than policy judgment."],"plain_english_summary":"Requires detailed visual inspections of the APU firewall on listed Embraer EMB‑135/145 serial numbers every 200 flight hours or 90 days, and mandates repair per the Structural Repair Manual or replacement of firewall part 145‑47494‑401 with part 145‑47494‑607 using Embraer service bulletins (or later CTA/ANAC‑approved revisions). It responds to reported APU firewall cracking to protect structural integrity and sealing; operators bear inspection, repair or replacement costs and must follow the specified documentation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-145-12-apu-firewall-2","history":"/api/acts/ad-emb-145-12-apu-firewall-2/history","analysis":"/api/acts/ad-emb-145-12-apu-firewall-2/analysis","conflicts":"/api/acts/ad-emb-145-12-apu-firewall-2/conflicts","importantCases":"/api/acts/ad-emb-145-12-apu-firewall-2/important-cases","documents":"/api/acts/ad-emb-145-12-apu-firewall-2/documents"}}