Summary
This document revises an earlier proposed airworthiness directive (AD); applicable to certain Cessna Model 500, 501, 550, and 551 airplanes; that would have required inspection of the piston housing for an "SB" impression stamp; a one-time inspection of the brake assembly to detect cracked or broken brake stator disks; and replacement of the brake assembly with a new or serviceable assembly, if necessary. This new action revises the proposed rule by eliminating the inspection of the brake assembly to determine if the letters "SB" have been impression-stamped on the piston housing, and, instead, requiring a one-time inspection of the brake stator disks to determine to what change level they have been modified (if any), and follow-on actions if necessary. This new proposed AD would also require that the existing markings on the piston housing of certain brake assemblies be eliminated. The actions specified by this new proposed AD are intended to prevent wheel lockups that may becaused by cracked or broken brake stator disks becoming jammed in the brake assembly and preventing rotation. Such jamming of the brake assembly may result in reduced directional control or braking performance during landing. This action is intended to address the identified unsafe condition.