Being creative with beer cans
These guys are building an aircraft out of empty beer cans. How noble!
Aircraft modeling or aeromodelling is a hobby that has been popular since the 1930s. It is constructing small airplanes using materials such as balsa wood, beer cans, 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.
Flying models have to be designed according to the same principles as full-sized aircraft, and therefore their construction is very different from most static models. In fact, construction techniques similar to full-sized aircraft (especially older ones) are often used. These might consist of forming the structure of the model using thin strips of light wood such as balsa, then covering it with fabric and doping it to make it stretch on the frame and become airtight.
Lightness is essential, but so is having sufficient strength to accommodate the forces of flight. Seen @ Quicksand