{"id":"F2007L02458","name":"AD/CL-600/81 - Vertical Beams on Pressure Bulkheads at FS 409+128 and FS 559","slug":"ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":67965,"registerId":"commonwealth-F2007L02458-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bombardier (Canadair) CL-600 (Challenger","sectionType":"division","heading":"Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes","content":"### Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes\n\n| AD/CL-600/81 | Vertical Beams on Pressure Bulkheadsat FS 409+128 and FS 559 | 9/2007 |\n| ------------ | ------------------------------------------------------------ | ------ |\n\n| Applicability: | Model CL-600-2B19 aircraft, serial numbers 7003 through 7999.                                                                                                                                                                                                                                                                                |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the requirements of Transport Canada AD CF-2003-08.                                                                                                                                                                                                                                                                |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of30 August 2007.                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 30 August 2007.                                                                                                                                                                                                                                                                            |\n| Background:    | Cracks were detected on the vertical beams on pressure bulkheads at fuselage stations 409+128 and 559 on several Regional Jet in-service aircraft. Failure of the vertical beams at the pressure bulkheads, which have been identified as principal structural element, would compromise the structural integrity of the pressure bulkheads. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n11 July 2007","sortOrder":0},{"sectionNumber":"AD/CL-600/81","sectionType":"part","heading":"AD/CL-600/81","content":"## AD/CL-600/81","sortOrder":1},{"sectionNumber":"Vertical Beams on Pressure Bulkheadsat F","sectionType":"part","heading":"Vertical Beams on Pressure Bulkheadsat FS 409+128 and FS 559","content":"## Vertical Beams on Pressure Bulkheads  \nat FS 409+128 and FS 559","sortOrder":2},{"sectionNumber":"9/2007","sectionType":"part","heading":"9/2007","content":"## 9/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This directive adopts Transport Canada AD CF-2003-08 for the specified CL-600-2B19 serial range and does not, on its face, expand or narrow the applicability beyond those serial numbers or the requirements in the referenced AD. The instrument’s text simply makes the Transport Canada requirements mandatory for the listed Australian-applicable aircraft, with an effective date of 30 August 2007."},"complexity_factors":["Cross-reference to an external instrument (Transport Canada AD CF-2003-08) — requires consulting another document to know exact actions and timelines","Technical specificity (structural element: vertical beams on pressure bulkheads at FS 409+128 and FS 559) — requires specialist inspection/repair capability","Narrow applicability (only CL-600-2B19 serial numbers 7003–7999) — requires operators to determine airframe serial applicability","Safety-critical consequences (failure would compromise pressure bulkhead integrity) — increases urgency and potential operational disruption","Administrative detail omitted from this text (no standalone procedures or timelines listed here) — increases compliance-burden on operators to trace requirements","Revised effective date noted (30 August 2007) — creates a concrete compliance start that affects scheduling and logistics"],"plain_english_summary":"This Airworthiness Directive requires operators of Bombardier CL-600-2B19 aeroplanes (serial numbers 7003–7999) to carry out the inspections and corrective actions set out in Transport Canada AD CF-2003-08 for vertical beams on pressure bulkheads at fuselage stations FS 409+128 and FS 559, after cracks were detected. CASA made the directive effective 30 August 2007; aircraft operators must follow the referenced AD and therefore bear the costs and operational impacts of inspection and repair."},"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 standard airworthiness directive with narrow, targeted scope. It addresses a specific structural defect in a specific aircraft model and does not appear to have expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only one substantive requirement: comply with an external Canadian directive","No defined terms section — relies entirely on referenced external document","Simple applicability criteria (specific model and serial number range)","Single compliance date with no conditional exceptions or alternative methods","No internal cross-references or nested provisions"],"plain_english_summary":"This Airworthiness Directive mandates owners/operators of Bombardier CL-600-2B19 regional jets (S/N 7003–7999) to carry out the inspections/repairs required by Transport Canada AD CF-2003-08 for cracks found in vertical beams of pressure bulkheads at two fuselage locations. These beams are principal structural elements; failure could cause rapid decompression or loss of control. Compliance is required by 30 August 2007."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559","history":"/api/acts/ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559/history","analysis":"/api/acts/ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559/analysis","conflicts":"/api/acts/ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559/conflicts","importantCases":"/api/acts/ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559/important-cases","documents":"/api/acts/ad-cl-600-81-vertical-beams-on-pressure-bulkheads-at-fs-409-128-and-fs-559/documents"}}