Aircraft modeling or aeromodelling is a hobby that has been popular since the 1930s. It involves constructing small airplanes using materials such as balsa wood, foam, fiberglass, etc. A vast array of designs are possible, from ultra-simple gliders such as that pictured, to highly accurate scale models, some of which can be very large - maybe 1/3rd scale or more. Models may be built either as static non-flying models, or as flying models (also known as aeromodelling). Construction techniques for the two are usually very different.