A flying column is a small, independent, military land unit capable of rapid mobility and usually composed of all arms. It is often an ad hoc unit, formed during the course of operations. The term is usually, though not necessarily, applied to forces less than the strength of a brigade. As mobility is its primary purpose, a flying column is accompanied by the minimum of equipment. It generally uses suitable fast transport; historically, horses were used, with trucks and helicopters replacing them in modern times.