What force propels an airplane forward?

The force that propels an airplane forward is thrust. Thrust is generated primarily by the aircraft's engines, whether they are jet engines or propellers, and is responsible for moving the aircraft through the air. It works against the opposing force of drag, which is the resistance experienced as the airplane moves through the air.

Understanding thrust is essential in aviation because it must be sufficient to overcome drag for an aircraft to become airborne and continue flying. It plays a critical role in the takeoff, climb, and acceleration phases of flight, ensuring that the airplane can maintain its intended speed and trajectory.

Lift is the force that allows an aircraft to rise off the ground but does not contribute to forward movement. Weight refers to the gravitational force acting on the airplane, pulling it down towards the Earth, while drag counteracts thrust and must be minimized for effective flight. Therefore, thrust is uniquely responsible for pulling or pushing the airplane forward through the air.