AD FAA-2011-1092

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model BD-700-1A10 and BD-700-1A11 airplanes. This AD was prompted by a report of deformation at the neck of the pressure regulator body on certain oxygen cylinder and regulator assemblies (CRA). This AD requires an inspection to determine if a certain oxygen CRA is installed and the replacement of oxygen CRAs containing pressure regulators having a certain part number. We are issuing this AD to prevent elongation of the pressure regulator neck, which could result in rupture of the oxygen cylinder, and in the case of cabin depressurization, oxygen not being available when required.