One of the early aicraft engines that did more than most in bringing aviation through its pioneering days to a more common and accepted place in everyday life. Built by the Curtiss company for both military and civilian aircraft from 1913 to 1918, the OX-5 was used by several aircraft that saw action in the First World War, including the famous JN-4 "Jenny".

The OX-5 produced 90 HP at 1400 RPM, and just over 12,600 were built.

There is a group of OX-5 enthusiasts and aging barnstormers known as the OX-5 Aviation Pioneers. Their motto is "Aviation History by those Who Lived It".