Which force opposes lift when an aircraft is in flight?

The force that opposes lift during flight is weight. Lift is generated by the wings of the aircraft when air flows over them, creating a pressure difference that lifts the aircraft upward. However, weight, which is the force due to gravity acting on the aircraft, pulls it downward. For an aircraft to maintain altitude, the lift must equal the weight.

During flight, when the lift generated exceeds the weight, the aircraft ascends; conversely, if the weight is greater than the lift, the aircraft descends. This balance between lift and weight is critical for stable flight. Understanding this interaction helps pilots manage phases of flight like takeoff, cruising, and landing effectively.

In contrast, thrust provides the forward motion to overcome drag, while lift itself is not a force that opposes lift; rather, it is the force being generated.