In this activity from Fetch! you will learn how to build a helicopter. After you launch it, consider all of the forces that are acting on your copter that might cause it to fly (air pressure) or fall (gravity). Watch the way it behaves when it flies. Did something in the design cause it to behave that way? Try different designs and note how they change the copter's behavior. Will a different design help the copter stay up in the air longer?