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

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This AD requires revising the Airworthiness Limitations section of the Instructions for Continuing Airworthiness of the Maintenance Requirements Manual to include revised threshold and repeat inspection intervals for the cargo door skin cut-out. This AD results from a report that a crack was discovered at the lower forward corner of a cargo door skin cut-out during fatigue testing. We are issuing this AD to detect and correct cracking in the lower forward corner of the cargo door skin cut-out, which could result in reduced structural integrity of the airplane.