Document Type: Historical Monograph Document Number: Smithsonian Annals of Flight #7

The date 28 September 1923 is an important one in the annals of aviation. On that day, at Cowes in England, the sixth international race for the Schneider Cup was held, and on that day the Schneider race changed drastically from a contest to evaluate speed, reliability, and navigability of seaplanes to an all-out, high-speed competition between world powers.

This change was brought about by two sleek, diminutive Curtiss racers that had been brought from America to challenge the European sea-planes. The Curtiss planes ran away from their competitors so convincingly that even those who had foreseen the result were surprised at the extent of the victory.

The apparent ease of the American win was forcefully significant; and the observant press was quick to praise the excellent combination of flying skill and advanced technology. The most important element of the victory soon was pinned down to the Curtiss D-12 engines. They proved to be powerful, light, and reliable, and they introduced a new dimension in power plants by having a frontal area for which one commentator found the correct adjective—"piccolissimo."

The D-12 engine is an excellent example of a first-line design in the history of aero engine development. It was the result not only of brilliant inspiration but of patient application, perseverance, and hard work on the part of its developers. To understand the origins of the D-12 it is necessary to go back to the autumn of 1915.