{"id":"F2008L02662","name":"AD/EMB-145/15 - APU Exhaust Duct Cracks","slug":"ad-emb-145-15-apu-exhaust-duct-cracks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74699,"registerId":"commonwealth-F2008L02662-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-145/15 | APU Exhaust Duct Cracks | 8/2008 |\n| ------------- | ----------------------- | ------ |\n\n| Applicability: | Embraer EMB-145( ) aircraft, serial numbers 145601, 145614 and 145626, fitted with APU cowling exhaust assembly P/N 145-52460-401, which forms part of APU cowling assembly P/N 145-52979-401.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Carry out a detailed visual inspection with a magnifying glass of 8X minimum in all APU exhaust gusset strap area, with emphasis in the spot weld points. If any crack is found, replace the exhaust duct with another bearing or cut the damaged duct P/N 145-50348-001 after the gusset strap area, preserving all not affected welded points.2. Repeat the inspection until the exhaust duct is replaced with another bearing with a different P/N not affected by this AD.The detailed instructions and procedures to accomplish this AD are described in the Embraer Alert Service Bulletin No. 145-49-A023, original issue, or further revisions approved by the CTA.Note: SERVIÇO PÚBLICO FEDERAL DEPARTAMENTO DE AVIAÇÃO CIVIL AD 2002-11-02 dated 28 November 2002 refers. |\n| Compliance:    | For Requirement 1 - Within 50 flight hours after the effective date of this AD, unless previously accomplished.For Requirement 2 - At intervals not exceeding 50 flight operating hours.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n|                | This Airworthiness Directive becomes effective on 31 July 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n| Background:    | Two cases of cracks in the non-silenced APU exhaust duct extension have been found which could lead to a duct separation during flight.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n20 June 2008","sortOrder":0},{"sectionNumber":"AD/EMB-145/15","sectionType":"part","heading":"AD/EMB-145/15","content":"## AD/EMB-145/15","sortOrder":1},{"sectionNumber":"APU Exhaust Duct Cracks","sectionType":"part","heading":"APU Exhaust Duct Cracks","content":"## APU Exhaust Duct Cracks","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":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical defect in a limited fleet. It has not expanded beyond its original purpose of mandating inspections for APU exhaust duct cracks."},"complexity_factors":["Highly specific applicability limited to 3 aircraft serial numbers and one specific part number","Contains only 2 main requirements with clear conditional logic (if crack found → replace or cut)","Single cross-reference to Embraer Service Bulletin for technical procedures","Simple compliance timeline (50 flight hours initial, then recurring)","No nested definitions or interpretation sections — terms used are standard aviation maintenance terminology","Document appears to be a formatted directive with some repetition/presentation artifacts but substantive content is brief"],"plain_english_summary":"This CASA Airworthiness Directive mandates repeated close inspections and corrective action on the APU exhaust duct of three Embraer EMB‑145 aircraft (s/n 145601, 145614, 145626) when fitted with part 145‑52460‑401. Cracks were found that could allow the duct to detach in flight; inspections (using at least 8× magnification) must begin within 50 flight hours and repeat every 50 hours until the duct is replaced or repaired as specified. Effective 31 July 2008."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument does not indicate any change of scope from its stated safety purpose. It targets reported cracks in the non-silenced APU exhaust duct and applies only to three identified airframes fitted with the specified part number, prescribing inspection frequency and remedial options (Applicability; Requirement; Background)."},"complexity_factors":["Narrow applicability limited to three specific aircraft serial numbers and a specific APU cowling exhaust assembly P/N (Applicability)","Precise technical inspection standard: detailed visual inspection using minimum 8× magnifying glass, focus on spot weld points (Requirement)","Short, repeating compliance interval (within 50 flight hours and then every 50 flight hours) creates operational scheduling and maintenance burden (Compliance)","Two corrective options: replace with a different P/N or cut the damaged duct after the gusset strap area while preserving unaffected welds — adds maintenance-choice complexity (Requirement)","Dependence on Embraer Alert Service Bulletin 145-49-A023 for detailed procedures and any approved revisions (Requirement)","Cross-reference to an earlier foreign AD (Brazilian DAC AD 2002-11-02) increases traceability and verification steps (Requirement Note)","Safety-critical risk stated (possible duct separation in flight) heightens urgency and may constrain operational flexibility (Background)","Fixed effective date and formal regulatory enforcement require documentation and record-keeping by operators (Effective date; Compliance)"],"plain_english_summary":"This Airworthiness Directive orders owners/operators of three Embraer EMB-145 aeroplanes (s/n 145601, 145614, 145626) fitted with APU cowling exhaust assembly P/N 145-52460-401 to perform a detailed 8× visual inspection of the APU exhaust gusset strap area and to replace or cut out cracked ducts per Embraer Alert Service Bulletin 145-49-A023. (Applicability; Requirement)\n\nInspections must be done within 50 flight hours and repeated at 50‑hour intervals until the duct is replaced; operators bear inspection and replacement costs and must follow the stated procedures. (Compliance; Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-145-15-apu-exhaust-duct-cracks","history":"/api/acts/ad-emb-145-15-apu-exhaust-duct-cracks/history","analysis":"/api/acts/ad-emb-145-15-apu-exhaust-duct-cracks/analysis","conflicts":"/api/acts/ad-emb-145-15-apu-exhaust-duct-cracks/conflicts","importantCases":"/api/acts/ad-emb-145-15-apu-exhaust-duct-cracks/important-cases","documents":"/api/acts/ad-emb-145-15-apu-exhaust-duct-cracks/documents"}}