Which force directly opposes drag during flight?

Thrust is the force that directly opposes drag during flight. In the context of aviation, drag is the aerodynamic resistance experienced by an aircraft as it moves through the air. To maintain forward motion and achieve flight, the engines of the aircraft generate thrust to overcome this drag.

When an aircraft accelerates, thrust must be greater than drag for the aircraft to increase its speed. Conversely, when cruising at a constant speed, thrust must equal drag to maintain that speed. Thus, the relationship between thrust and drag is critical for flight performance and control.

Other forces like weight and lift play important roles in flight dynamics but do not directly counteract drag. Weight acts vertically downward due to gravity, while lift acts vertically upward to offset weight. Therefore, while understanding the balance of all these forces is essential, it is thrust that directly addresses the aerodynamic resistance of drag.