Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: There have been several cases of wing leading edge anti-ice piccolo duct failure reported on CL-600- 2B19 (CRJ) aircraft. Upon investigation, it was determined that ducts manufactured since May 2000 are susceptible to cracking due to the process used to drill holes in the ducts. This cracking may cause air leakage, with a possible adverse effect on the anti-ice air distribution pattern and anti-ice capability, without annunciation to the flight crew [and consequent reduced controllability of the airplane]. It has subsequently been determined that faulty ducts may also have been installed in a number of leadingedge assemblies built as spares and whose current locations are not specifically known. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.