There are three primary types of reciprocating engines used to power airplanes, including radial, in-line and flat. Radial reciprocating engines live up to their namesake by performing radial movements with their cylinders. In-line reciprocating engines, on the other hand, feature banks of cylinders.

Reciprocating engines may be classified according to the cylinder arrangement (in line, V-type, radial, and opposed) or according to the method of cooling (liquid cooled or air cooled).