Airworthiness Directives; Raytheon Model HS.125 Series 700A and 700B Airplanes; Model BAe.125 Series 800A (Including Variants C-29A and U-125), 800B, 1000A, and 1000B Airplanes; and Hawker 800 (Including Variant U-125A), 800XP, and 1000 Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Raytheon Model BAe.125 series 800A (including variants C-29A and U- 125), 800B, 1000A, and 1000B airplanes and Model Hawker 800 (including variant U-125A) and 1000 airplanes; and for certain Raytheon Model HS.125 series 700A and 700B airplanes and Model Hawker 800XP airplanes. This AD requires measuring the resistance of the current limiters for the PE, PS1, and PS2 busses, and replacing a current limiter with a new part if necessary. This AD also requires reporting certain information to the airplane manufacturer. This AD allows a records review for determining if suspect current limiters were installed, which may exempt airplanes from the required measurement. This AD results from reports that certain current limiters have opened within two to four hours after installation. We are issuing this AD to prevent loss of all primary electrical power, which could result in the airplane operating only under emergency power.