A radial engine is a type of internal combustion engine where the cylinders are arranged in a circular pattern around a central crankshaft. This design allows for a compact engine that can produce a lot of power relative to its size. Radial engines are commonly used in aircraft, especially in vintage models, due to their reliability and efficient cooling. The engine operates by having each cylinder fire in a sequence, which helps to balance the forces and reduce vibrations. World War II aircraft often featured radial engines, making them a significant part of aviation history. Their unique design contributes to the distinctive sound and performance of these planes.