Airworthiness Directives; Bombardier, Inc. Airplanes

We propose to supersede Airworthiness Directive (AD) 2015-03- 01, for all Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. AD 2015-03-01 currently requires installing additional attaching hardware on the left and right fan cowl access panels and the nacelle attaching structures. Since we issued AD 2015- 03-01, there have been updates to the weight and balance data needed to calculate the center of gravity for affected airplanes. This proposed AD would require weight and balance data to be included in the Weight and Balance Manual and applicable logbooks for airplanes modified per Bombardier Service Bulletin 601R-71-034, Revision B, dated August 1, 2014. The proposed AD would also require the weight and balance data to be used in order to calculate the center of gravity for affected airplanes. We are proposing this AD to prevent damage to the fuselage and flight control surfaces from dislodged engine fan cowl panels, and prevent incorrect weight and balance calculations. Incorrect weight and balance calculations may shift the center of gravity beyond approved design parameters and affect in-flight control, which could endanger passengers and crew.