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

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes, that currently requires repetitive lubrication of the slide shaft of the input plunger of the brake control valve assembly. This amendment adds requirements for modifying the brake control valve assembly, which terminates the repetitive lubrications required by the existing AD. This amendment also adds subsequent repetitive lubrications of the valve utilizing the grease fittings installed during the modification. This amendment is prompted by reports of temporary loss of braking action upon landing. The actions specified by this AD are intended to prevent temporary loss of braking action due to the freezing of moisture on the input plunger of the brake control valve during steep descent.