Which factor contributes to induced drag during flight?

Induced drag is a type of drag that occurs as a byproduct of lift generation. When the wings of an aircraft produce lift, they also create a pressure difference between the upper and lower surfaces of the wing. This pressure difference leads to vortex formation at the wingtips, which in turn contributes to induced drag. As the angle of attack increases, the lift increases, but so does the induced drag. Therefore, the primary factor that contributes to induced drag during flight is the lift being created by the wings.

The other factors listed do not directly influence induced drag in the same way. For example, the shape and design of the fuselage can impact overall drag but it does not contribute specifically to induced drag. Similarly, the weight of the aircraft primarily affects the amount of lift required but does not create induced drag directly. Wind conditions at altitude can influence flight performance and drag but are external factors and do not impact the direct relationship between lift and induced drag.