What is the function of stall warning systems?

The function of stall warning systems is to alert pilots when the aircraft is approaching a stall condition. A stall occurs when the airflow over the wings is disrupted, leading to a loss of lift. Stall warning systems are crucial for flight safety as they provide an early indication that the aircraft is nearing a stall, allowing pilots to take corrective action, such as reducing the angle of attack or increasing thrust, to prevent an actual stall from occurring. This system typically includes visual and/or auditory alerts, which help ensure that pilots remain aware of their aircraft's aerodynamic performance, especially during critical phases of flight like takeoff and landing.

The other choices do not correctly represent the purpose of stall warning systems. For instance, regulating engine temperature, enhancing fuel efficiency, and assisting in autopilot engagement are functions associated with different systems within the aircraft, but they do not pertain to the critical function of indicating an impending stall situation.