What does the term "stall warning" refer to in aviation?

The term "stall warning" in aviation specifically refers to a safety feature designed to indicate an impending stall condition. This is crucial for pilots as a stall occurs when an aircraft exceeds its critical angle of attack, causing a significant loss of lift. The stall warning system typically utilizes various sensors to detect when the aircraft is approaching this critical point, providing audible or visual alerts to the pilot. This early warning allows pilots to take corrective actions to prevent the stall, ensuring the safety and control of the aircraft.

In contrast, the other options do not accurately describe stall warnings. Changes in airspeed may be indicated by various flight instruments, but they are not specifically classified as stall warnings. A notification regarding the landing gear deployment is related to landing gear systems rather than stall avoidance. Lastly, a signal indicating a maintenance issue pertains to aircraft performance or condition unrelated to stall conditions. Therefore, option B accurately captures the essence and purpose of stall warning systems in aviation.