A proposed FAA Airworthiness Directive targets the Embraer Phenom 100’s angle-of-attack (AOA) system. The FAA believes the accumulation of moisture between the AOA vane base assembly and the stationary ring of the sensor’s body can freeze under certain conditions. If freezing occurs both AOA sensors may get stuck and the stall warning protection system will no longer be effective, potentially resulting in aerodynamic stall and loss of airplane control.