Which factor can increase an aircraft's drag during flight?

Increasing an aircraft's weight can lead to a rise in drag during flight due to several aerodynamic principles. When the weight of an aircraft increases, the aircraft may require a higher angle of attack to maintain level flight. This altered angle can create more induced drag, which is a type of drag that increases with lift – and since weight directly affects lift requirements, the heavier the aircraft, the greater the induced drag.

Moreover, as the aircraft's weight increases, it may lead to adjustments in its flight profile, potentially increasing lift-induced drag further. This concept is crucial in understanding how weight management and payload affect overall flight efficiency and performance.

In comparison, decreasing the wing area would typically reduce the amount of drag by minimizing the surface area exposed to the airflow. Increasing speed may cause an increase in another type of drag known as profile drag or parasitic drag, but this is not the only factor at play when weight is considered. Enhancing engine power mainly increases thrust and can indirectly influence drag but does not directly contribute to its increase. Understanding these dynamics is essential for mastering aircraft performance characteristics.