To maintain altitude during a turn, the angle of attack must be increased to compensate for the decrease in what component?

To maintain altitude during a turn, the angle of attack must be increased to compensate for the decrease in the vertical component of lift. When an aircraft banks into a turn, the lift vector tilts, which causes the vertical component of lift to decrease. This is because the total lift is divided into two components: the vertical component that counters weight and the horizontal component that facilitates the turn.

In a level flight condition, the vertical component of lift must equal the weight of the aircraft to maintain altitude. When the aircraft begins the turn, the total lift still exists, but it is now directed at an angle. As a result, the vertical component of lift diminishes, leading to a potential descent unless the angle of attack is increased. By increasing the angle of attack, the pilot generates more lift overall, restoring the necessary vertical component to maintain altitude.

The other components, such as drag and thrust, do not directly contribute to maintaining altitude in the context of turning flight. While maintaining adequate thrust is necessary for speed and to overcome drag, the specific adjustment in angle of attack to compensate for changes in lift during a turn focuses on the vertical component, making it the correct answer.