What does the stall warning system utilize to detect stall conditions?

The stall warning system in the Pilatus PC-12 NG utilizes angle of attack sensors to detect stall conditions. Angle of attack (AOA) refers to the angle between the chord line of the wing and the oncoming airflow. As the aircraft approaches a stalling condition, the AOA increases, which is critical for assessing the performance limits of the wing. The stall warning system monitors these AOA measurements to predict when the aircraft is nearing a stall, providing timely alerts to the pilot to take corrective actions.

Using angle of attack sensors is advantageous because they provide a more accurate indication of the aircraft's aerodynamic state compared to other methods. Unlike airspeed indicators, which can be influenced by various variables like weight and configuration, AOA provides a direct measurement of the aerodynamic limits of the aircraft regardless of its airspeed or other factors. This allows for more reliable detection of stall conditions and enhances flight safety.

Other options such as pressure sensors, airspeed indicators, and vertical speed indicators do not directly measure the angle of attack, and while they may provide relevant information regarding flight dynamics, they do not represent the primary means of stall detection in this aircraft.