A foamy (also foamie; pl: foamies) is an R/C aircraft constructed of either flat or injection molded plastic foam similar to Styrofoam.
Flat, laser-cut foamies are responsible for a surge in the popularity of indoor 3-D electric flight. Injection molded foamies are becoming extremely popular for their relative low cost, ease of assembly and the fact that complex curves and surfaces similar to the original prototype can be easily incorporated.
Unlike their more traditionally constructed counterparts, foamies are easily repaired in the field after a crash. Replacement parts may be purchased and easily installed as well.
Some special care is required in the maintenance, construction and use of foamies. Aerosol spray paints will attack and weaken the foam; large surfaces should be painted with an airbrush. Ordinary cyanoacrylate adhesives will attack foam as well. Odorless, "foam friendly" CA may be used as can Shoe Goo or similar contact cement. Direct sunlight can warp and bubble foamies, so their use in hot weather is not recommended. Even under relatively cool conditions, foamies should be kept from direct sunlight when not in use.
Extremely light foamies should not be flown outdoors when the wind is more than 5 mph (8 km/h). Vacuformed or built-up foamies with their greater size and strength may be flown in winds up to about 10 mph (16 km/h).