Airworthiness Directives; Aerospatiale Model ATR42-200, -300, and -320 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Aerospatiale Model ATR42-200, -300, and -320 series airplanes, that requires modifying the wiring of the starting rotary switch. The actions specified by this AD are intended to prevent the loss of electrical power supply of the direct current (DC) emergency and standby buses, which could result in the loss of some electrical loads and the consequent display of erroneous information to the flight crew. This action is intended to address the identified unsafe condition.