Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604 Variants) airplanes. This proposed AD was prompted by reports of deformation at the neck of the pressure regulator body on the oxygen cylinder and regulator assemblies (CRAs), and an electrical wiring harness in the area of the oxygen cylinder had no protective conduit sleeving. This proposed AD would require inspecting to determine if certain oxygen pressure regulators are installed and replacing oxygen CRAs containing pressure regulators that do not meet the required material properties. This proposed AD would also require inspecting for damaged wiring and repairing or replacing wiring if necessary. We are proposing this AD to prevent rupture of the oxygen cylinder, which in the case of cabin depressurization, oxygen would not be available when required; and to detect and correct unprotected wiring that could chafe against the oxygen systemcomponents or surrounding structure in the area, which could lead to electrical arcing and an oxygen-fed fire.