At the beginning of the 1910s, the rapid development of the aeronautical sector prompted various companies to engage in the development of new engines specifically designed for aircraft and airships. Similarly to FIAT and SPA, the Officine Meccaniche Colombo in Milan also began the study of a liquid-cooled engine with six-in-line cylinders. Named D110, its production started in 1916 and it was also built under license by other companies, including Alfa Romeo and Officine Meccaniche De Vecchi (later C.N.M.1) in Milan. The D110 engine was used in various aircraft built in Italy during the First World War and in the following years. Its construction scheme takes up some technical features quite widespread at the beginning of the 1900s: first of all the use of groups of twin cylinders arranged in line on a single aluminum alloy base, with heads made in one piece with the cylinders, in order to reduce the length of the motor. Unlike other engines of the era, the cooling jackets are made of sheet brass, screwed (rather than welded) externally onto each set of cylinders. Overall, the D 110 engine offered performance and reliability in line with those of its direct competitors, including the FIAT A 10. Some D110, such as the engine on display, continued to be overhauled and used after the end of the First World War.