Under what condition will an airplane stall?

An airplane will stall when it exceeds a critical angle of attack, which is a specific angle that varies slightly depending on the aircraft's design. Importantly, the stall angle remains constant regardless of the airplane's attitude in terms of pitch or orientation relative to the horizontal plane. This means that regardless of whether the airplane is climbing, descending, or in straight and level flight, if the angle of attack exceeds this critical limit, a stall will occur.

This relationship highlights the importance of maintaining awareness of the angle of attack in various flight attitudes to prevent unintentional stalls. Additionally, it is crucial to recognize that other conditions such as weight, balance, and configuration (like flaps) can influence stall characteristics, but the fundamental relationship between the angle of attack and stalling pertains primarily to the angle itself rather than external factors like altitude or airspeed.

Understanding this concept helps pilots manage their flight techniques effectively, ensuring they operate within safe limits under various flight conditions.