What does the "stick shaker" indicate to pilots?

The "stick shaker" is a warning device found in many aircraft that operates as a tactile cue to alert pilots of an impending stall. When the aerodynamic conditions indicate that the aircraft is approaching stall speed—an aerodynamic state where the smooth airflow over the wings is disrupted, leading to a significant loss of lift—the stick shaker activates. This provides an essential warning, giving pilots crucial time to take corrective actions, such as reducing the angle of attack or increasing power, to prevent the stall from occurring. This mechanism ensures that pilots remain aware of their aircraft's performance and can respond appropriately to maintain safe flight conditions. Thus, this warning is specifically designed to indicate that immediate attention is required to avoid potentially dangerous situations associated with stalling.