In order to maintain altitude at a slower airspeed, the angle of attack must:

To maintain altitude while flying at a slower airspeed, it is essential to increase the angle of attack. This is because as airspeed decreases, the lift generated by the wings also diminishes. The angle of attack is crucial in creating lift; a higher angle of attack helps to compensate for the loss of lift that occurs as speed decreases. By increasing the angle of attack, the wings can generate enough lift to support the aircraft's weight and maintain altitude despite the slower airspeed.

However, it's important to manage this increase carefully. There is a limit to how much the angle of attack can be increased before stall conditions may occur, where the airflow begins to separate from the wing's surface, leading to a loss of lift. Therefore, pilots must be knowledgeable about their aircraft's performance characteristics and the stall angle to adjust the angle of attack appropriately while flying at slower speeds.