Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

This amendment revises an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet series 100 & 440) airplanes, that currently requires revising the airworthiness limitations section of the Instructions for Continued Airworthiness by incorporating new structural inspection intervals for the pressure floor skin of the center fuselage at fuselage stations 460 and 513; repair if necessary; and submission of inspection findings to the airplane manufacturer. This amendment terminates the reporting requirement and includes a provision to allow removal of the referenced service information when the information specified in it is included in the general revisions of the maintenance manual. The actions specified in this AD are intended to detect and correct in a timely manner fatigue cracks of the pressure floor skin of the center fuselage at fuselage stations 460 and 513, which could result in failure of the pressure floor skin and consequent rapid decompression of the airplane during flight. This action is intended to address the identified unsafe condition.