Airworthiness Directives; Raytheon Model Hawker 800XP Series Airplanes, and Hawker 800 (U-125A Military Derivative) Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Raytheon Model Hawker 800XP series airplanes and Hawker 800 (U-125A military derivative) airplanes. This action requires removal of the sealant from the firewall mounting flanges and mounting points of the fire extinguisher assemblies; removal of sealant obstructing the discharge tubes of the fire extinguisher assemblies; cleaning and flushing of the mounting flanges, mounting points, and discharge tubes with solvent; and installation of new gaskets on the firewall mounting flanges and mounting points. This amendment is prompted by reports of excessive sealant applied during manufacture of the firewall mounting flanges and mounting points of the fire extinguisher assemblies, which subsequently entered and obstructed the discharge tubes. The actions specified in this AD are intended to prevent obstructions of the discharge tubes of the fire extinguisher assemblies, which could result in improper distribution of the fire extinguishing agent within the nacelle in the event of a fire.