The Engineering Division XCO-6 was an American two-seat observation biplane designed by the United States Army Engineering Division, only two were built and the type did not enter production.
Design and development
Two prototypes of the XCO-6 were built powered by a 420 hp (313 kW) inverted air-cooled V-1710 engine. One was tested at McCook Field and subsequently modified but no others were built.
- Prototype two-seat single-engined observation biplane.
- Proposed variant with the main fuel tanks moved into the upper wing, not built.
- A XCO-6 modified with a change of engine to a 435 hp (324 kW) Liberty 12A engine.
- XCO-6B modified with a larger propeller and changes to the landing gear.
Data from 
- Crew: 2
- Length: 29 ft 8 in (9.04 m)
- Wingspan: 48 ft 0 in (14.63 m)
- Powerplant: 1 × Liberty V-1410 V-12 water-cooled piston engine, 420 hp (310 kW)
- Related lists
- 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.