Here’s a picture from a plane ride. I can’t remember when this was, but the sky was at least magnificent and stunning to look at. An average plane uses about 1 gallon of fuel EVERY SECOND! (Which is approximately 4 liters!) In other words, it takes a lot of energy to hold up a plane. Not only does the fuel have to give power to the engine, the plane also causes a lot of moving air during the process to hold itself up! The wings are mainly to make use of the moving air, and to lift the plane of the ground.