Radial Engine

A radial engine is a reciprocating internal combustion engine whose cylinders radiate outward from a central crankcase like the spokes of a wheel, giving it a star-shaped profile when viewed from the front; it was the dominant configuration for aircraft engines before gas turbines took over. Charles M. Manly built the earliest known radial engine in 1901, a water-cooled five-cylinder design producing 52 horsepower for Samuel Langley's Aerodrome aircraft, and the inventor Jacob Ellehammer built what is recognized as the first air-cooled radial engine between 1903 and 1904, later fitting a five-cylinder version to his triplane around 1907. Alessandro Anzani's three-cylinder radial engine powered Louis Bleriot's crossing of the English Channel in 1909, and Anzani went on to build radial engines up to twenty cylinders and 200 horsepower by 1914, helping establish the configuration through aviation's early decades.