I am an avid RC Scale model builder. The pictured aircraft is the Steen Skybolt with a 55cc. gas engine, an 80" top wing and weighing in at about 21lbs. It flies extremely well and is very aerobatic. Others are a 1/4 scale PA18 Suoer Cub on floats with a 30CC engine, and a 1/5 scale WACO YMF with a 23CC engine, plus a 1/4 scale WACO ARE with a 55cc engine based on the New York Daily News photography version built about 1941. All are gas engines.