Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet series 100) series airplanes, that currently requires repetitive lubrication with grease of the sliding shaft of the input plunger of the brake control valve assembly. This action would add requirements for modifying the brake control valve assembly, and subsequent repetitive lubrications of the valve. Accomplishment of the modification would terminate the repetitive lubrications of the sliding shaft of the input plunger required by the existing AD. This proposal is prompted by reports of temporary loss of braking action upon landing. The actions specified by the proposed AD are intended to prevent temporary loss of braking action due to the freezing of moisture of the input plunger of the brake control valve during steep descent.