Summary
This document revises an earlier proposed airworthiness directive (AD), applicable to certain Raytheon Model BAe.125, Hawker 800 (U-125A military) and Hawker 800XP series airplanes that would have required removal of existing clamps, bedding tapes, and rubber connecting sleeves at the ends of the turbine air discharge duct and the water separator, and replacement of the clamps and rubber connecting sleeves with new, improved components. This new action revises the proposed rule by adding airplanes to the applicability; and, for certain airplanes, adding a new requirement to remove aluminum bedding strips that are installed under the existing clamps. The actions specified by this new proposed AD are intended to prevent the turbine air discharge duct or water separator outlet duct from disconnecting from the cold air unit turbine or from the water separator, resulting in the loss of air supply to maintain adequate cabin pressure. Loss of adequate cabin pressure at high altitude would require emergency procedures, such as use of oxygen, auxiliary pressurization, or emergency descent.