Two prototypes of the XCO-6 were built powered by a 420 hp (313 kW) inverted air-cooled V-1710 engine.[1] One was tested at McCook Field and subsequently modified but no others were built.[1]
Andrade, John (1979). U.S. Military Aircraft Designations and Serials since 1909. Hinckley, Leicstershire, UK: Midland Counties Publications. p. 171. ISBN 0-904597-22-9.