Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Raytheon Model DH.125, Model HS.125, Model BH.125, Model BAe.125 Series 800A, Model Hawker 800, Model Hawker 800XP, and Model Hawker 1000 series airplanes. This proposal would require leak checks and inspections for corrosion of the pitot/static and stall vent drain valves, and replacement of certain components, if necessary. This proposal is prompted by reports of plugged or taped drain valves as well as consequent corrosion of certain drain valves. The actions specified by the proposed AD are intended to prevent erroneous altimeter and airspeed indications due to plugged or taped pitot/static and stall vent drain valves.