Have students take another sheet of paper and hold it at one end. Then have them blow very hard over the top of it. Ask them to explain what is happening. Explain to the students that the paper rises slightly because of the moving air above it causes the pressure to be lower and lift is created. The airplane operates in the same manner.
Air travelling across the top has to travel faster than the air below.
This creates the lift which makes the airplane fly. This is called the principal of flight. Make a water-wheel by using a 2 liter plastic pop bottle and a piece of coat hanger. Put a hole into the cap and the bottom of the 2 liter bottle so that the piece of coat hanger will fit into the hole. The bottle can then spin and rotate around it.