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

In aviation, the term "stall" specifically refers to a condition where an aircraft loses lift due to exceeding its critical angle of attack. When the angle of attack—the angle between the wing's chord line and the oncoming airflow—increases beyond a certain point, the airflow can no longer smoothly adhere to the wing's surface. This disruption in airflow leads to a significant reduction in lift, resulting in a stall.

Understanding stalls is crucial for pilots as they need to recognize the signs and recover from them effectively. Stalls can occur in various flight conditions, including during critical phases like takeoff and landing, making it vital for pilots to maintain awareness of their aircraft’s angle of attack.

The other options represent unrelated aviation concepts. A stall is distinctly not related to high-speed flight, as high speed typically allows for more lift, nor is it about engine failure or low fuel, which are different operational issues requiring separate considerations.