Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702), CL-600-2D15 (Regional Jet Series 705), and CL-600-2D24 (Regional Jet Series 900) airplanes. This proposed AD was prompted by a report that traces of oil could be found in the crew oxygen system due to the use of incorrect pressure testing procedures during manufacturing. This proposed AD would require cleaning the crew oxygen system. We are proposing this AD to detect and correct oil contaminants, which could cause an ignition and result in a fire in the oxygen system.