Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-215-6B11 (CL-215T Variant), and CL- 215-6B11 (CL-415 Variant) airplanes. This proposed AD was prompted by a report that during a routine inspection, corrosion was discovered on the lower bearing of the rudder upper torque tube. This proposed AD would require applying grease to the bearing; doing a general visual inspection of the expelled old grease for any contaminants, metal wear, and indication of corrosion, and replacing the bearing if necessary; revising the maintenance or inspection program, as applicable, to incorporate the rudder spring tab operational test and a check of the rudder spring tab operation into the daily inspection. We are proposing this AD to prevent corroded bearings, which could result in a partial or total loss of axial support.