The Curtiss-Wright Corporation is one of the most important US aviation companies. Founded in 1929 from the merger of Curtiss Airplane and Motor Company, Wright Aeronautical and other aeronautical companies, nowadays it operates in many other fields, such as aerospace, with a large production including aircraft and engines. From early 1930s its Cyclone-series engines became very spread and technically appreciated all over the world. Produced for over 30 years with a total of over 200,000 units, they were used all over the world in numerous military and civilian aircraft up to the 1980s. This longevity was due to the layout of the original project introduced in 1930, which allowed a wide technical evolution: from the single-row 9-cylinder R-1820 up to the larger double-row engines, such as the 14-cylinder R-2600 and 18-cylinder R-3350. Each of them was progressively developed in various sub-series with better performance, greater reliability, and service economy. In particular, the R-1820 model was manufactured from the second half of the 1930s up to to the mid-1940s, for a total production of over 150,000 units that were used in a wide range of military aircraft.