{"id":"F2009L03445","name":"AD/CL-600/118 - Bulkhead Check Valves","slug":"ad-cl-600-118-bulkhead-check-valves","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":141079,"registerId":"commonwealth-F2009L03445-current","compilationNumber":null,"startDate":"2026-04-03","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-600/118 | Bulkhead Check Valves | 10/2009 |\n| ------------- | --------------------- | ------- |\n\n| Applicability: | Bombardier Inc. Model CL-600-2B19, Serial Numbers 7003 and subsequent.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Revise the Transport Canada approved maintenance schedule by incorporating the discard task, Task Number 21-51-21-13, for the bulkhead check valves, P/N 92E20-3 and 92E20-4.This task was introduced by Temporary Revision (TR) 1-2-39, dated12 December 2008, to the Maintenance Requirements Manual, CSP A-053, Part 1, Maintenance Review Board Report, Section 2, System and Powerplant Program.Note: Transport Canada AD CF-2009-31 dated 8 July 2009 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Compliance:    | Within 60 days after the effective date of this AD unless previously accomplished.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n|                | This Airworthiness Directive becomes effective on 24 September 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Background:    | Three cases of in-flight loss of cabin pressurization have been reported, resulting from failure of a bulkhead check valve in combination with failure of an air supply duct.In addition to mandating inspection, rework and/or replacement of the air supply ducts, AD/CL-600/80 (Transport Canada AD CF-2003-05R1) mandated the incorporation of a 4,000 flight-hour repetitive inspection task for bulkhead check valves, Part Numbers (P/N) 92E20-3 and 92E20-4, into the approved maintenance schedule. However, this repetitive inspection task has since been superseded by a 3,000 flight-hour periodic discard task for these bulkhead check valves.This AD mandates revision of the approved maintenance schedule to incorporate the discard task for bulkhead check valves, P/N 92E20-3 and 92E20-4, and supersedes the instructions detailed in Corrective Actions, Part A, of Transport Canada ADCF-2003-05R1, subsequently mandated by AD/CL-600/80. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n14 August 2009","sortOrder":0},{"sectionNumber":"AD/CL-600/118","sectionType":"part","heading":"AD/CL-600/118","content":"## AD/CL-600/118","sortOrder":1},{"sectionNumber":"Bulkhead Check Valves","sectionType":"part","heading":"Bulkhead Check Valves","content":"## Bulkhead Check Valves","sortOrder":2},{"sectionNumber":"10/2009","sectionType":"part","heading":"10/2009","content":"## 10/2009","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 AD maintains its original narrow scope — addressing a specific mechanical failure mode in specific aircraft through a specific maintenance task update. It does not expand beyond aviation safety into other regulatory areas."},"complexity_factors":["Single, specific technical requirement (one maintenance task update)","Limited applicability (one aircraft model, specific serial numbers)","Clear compliance deadline (60 days from effective date)","Minimal cross-referencing (only references one previous AD and one Transport Canada document)","No conditional logic or exceptions","Short document (approximately 250 words of substantive content)"],"plain_english_summary":"CASA orders operators of Bombardier Challenger CL-600-2B19 (S/N 7003 and up) to amend maintenance manuals to add a task requiring discard-and-replace of specific bulkhead check valves every 3,000 flight hours. The change, required within 60 days of 24 Sep 2009, follows in-flight cabin depressurisations linked to valve failures and replaces an earlier AD that only mandated inspections."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. The directive shifts the mandated action from a 4,000 flight‑hour repetitive inspection to a 3,000 flight‑hour periodic discard of the bulkhead check valves and expressly supersedes the corrective-action instructions previously mandated in AD/CL-600/80 and Transport Canada AD CF-2003-05R1 (Background; Requirement)."},"complexity_factors":["Narrow technical applicability to a single model and serial range (Applicability).","Specific parts identified by part number, requiring parts tracking and replacement (Requirement: P/N 92E20-3 and 92E20-4).","Mandatory revision of the approved maintenance schedule and incorporation of a discard task (Requirement).","Short regulatory compliance window of 60 days from the effective date (Compliance).","Interaction with existing airworthiness directives and maintenance manuals — the AD supersedes prior inspection instructions (Background).","Operational burden concentrated on aircraft operators who must perform the schedule revision and discard task (Requirement; Compliance)."],"plain_english_summary":"This directive requires operators of Bombardier CL-600-2B19 aeroplanes (serial 7003 onward) to update their Transport Canada–approved maintenance schedule to add a 3,000 flight‑hour discard task for bulkhead check valves (P/N 92E20-3 and 92E20-4). It must be implemented within 60 days and replaces a prior 4,000 flight‑hour inspection requirement intended to reduce in‑flight cabin depressurisation incidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-118-bulkhead-check-valves","history":"/api/acts/ad-cl-600-118-bulkhead-check-valves/history","analysis":"/api/acts/ad-cl-600-118-bulkhead-check-valves/analysis","conflicts":"/api/acts/ad-cl-600-118-bulkhead-check-valves/conflicts","importantCases":"/api/acts/ad-cl-600-118-bulkhead-check-valves/important-cases","documents":"/api/acts/ad-cl-600-118-bulkhead-check-valves/documents"}}