Wing is the major component for the lift production in an aircraft. Anything light is easy to fly. But that is not the only requirement for flying. It has to be safe too. Hence, we need to think about strength. Our kids attempted to design their own lightweight airplane wing using papers, plastic etc. If we consider a paper which is light in weight, it cannot bear the load of a cup of pebbles, stones, water etc. But if the same paper is designed with hollow structures, then it can be made strong enough to carry heavy loads.