Airworthiness Directives; Bombardier, Inc. Airplanes

We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, and Model CL-600-2D24 (Regional Jet Series 900) airplanes. This proposed AD was prompted by a report indicating that some operators have inadvertently removed the existing insulation blankets from the upper wing box area. This proposed AD would require inspecting for and replacing missing insulation blankets in the upper wing box area. We are proposing this AD to detect and replace missing insulation blankets from the upper wing box area, which could result in inadequate thermal protection to prevent fuel ignition in the event of an undetected bleed air leak due to a cracked or ruptured bleed-air duct.