Lets look at just how airplanes fly backwards. In airfoils and Reynolds numbers in and out of wind tunnels (This
is just inside stuff, ha ha!) Equilibrium, balance and weight can relate to different things.
Weight is the graviational force of the entire aircraft structure.
Gross Weight: The maximum weight that an aircraft or design can weigh and fly relatively safetly.
Useful Load: The amount of weight an aircraft or design can carry safely
Empty Weight: The amount the aircraft or design weighs by itself sitting on the ground with its fluids and usual
permanent equipment but not fuel.
