Which condition leads to increased induced drag?

Induced drag is a type of aerodynamic drag that occurs as a result of lift generation. It is particularly influenced by the angle of attack, which is the angle between the wing's chord line and the oncoming airflow. When the angle of attack increases, the lift produced by the wing also increases, but this greater lift comes at the cost of increased induced drag.

As the lift increases, the wing generates more vortices at the tips due to the pressure difference between the upper and lower surfaces of the wing. These vortices create additional turbulence in the airflow, which contributes to increased induced drag. Therefore, a greater angle of attack leads to higher levels of induced drag because it increases the lift required to maintain flight, amplifying the associated drag effects.

Other factors such as speed and altitude do not directly increase induced drag in the same way a greater angle of attack does. For instance, while high-speed flight can lead to other forms of drag like wave drag or profile drag, it generally decreases induced drag because it allows the aircraft to operate at lower angles of attack for the same lift.