That's not quite right! There are actually four main forces acting on an airplane in flight. They are:

1. Lift: This is the upward force that opposes gravity and keeps the airplane in the air. It's generated by the shape of the wings and the airflow over them.

2. Weight: This is the downward force due to gravity acting on the airplane's mass.

3. Thrust: This is the forward force that propels the airplane through the air. It's generated by the engines.

4. Drag: This is the backward force that opposes the airplane's motion. It's caused by friction between the air and the airplane's surfaces.

So, while you're close, there's more to the story than just lift and weight!