Airworthiness Directives; Bombardier, Inc., Airplanes

We are superseding Airworthiness Directive (AD) 2012-25-02, which applied to certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. AD 2012-25-02 required revising the airworthiness limitations section (AWL) of the instructions for continued airworthiness (ICA) of the maintenance requirements manual (MRM) by incorporating new procedures for repetitive inspections for cracking of the rear pressure bulkhead (RPB). AD 2012-25-02 also required revising the maintenance or inspection program to incorporate a revised task. This AD also mandates modification of the RPB and adds repetitive inspections for cracking of the RPB web, which terminates certain actions in this AD. This AD was prompted by additional in- service crack findings, which resulted in the development of a structural modification to the RPB. We are issuing this AD to address the unsafe condition on these products.