Development and Design
In 1924, specifically for a competition held by the U.S. Army Air Service, engineers Charles Cox and Alexander Klemin developed an aircraft designated CO-1. The aircraft was based on the German Heinkel HD.17, but featured a modified tail unit and interplane struts with increased chord.
A second example, designated CO-2, received a new powerplant: a twelve-cylinder Liberty L-12 engine with 400 hp.
USAAS Evaluation and Outcome
Both aircraft were delivered to the USAAS at McCook Field and were assigned tail numbers P-377 and P-379, respectively. However, the aircraft failed to generate interest and were returned to the company.
Designation Clarification and Legacy
It should be noted that the designation CO-1(2) was purely a company designation and did not align with the official U.S. Army Air Service designation system, which listed other aircraft (Engineering Division CO-1 and CO-2) under those numbers. According to one unverified source, at least one aircraft from the Cox-Klemin Aircraft Corporation was eventually refined and tested by the military under the official designation XO-4.
Technical Specifications
| Modification | CO-1 |
| Wingspan, m | 12.90 |
| Length, m | 9.30 |
| Height, m | 3.25 |
| Wing area, m2 | 39.00 |
| Empty weight | 1370 |
| Maximum takeoff weight | 2150 |
| Engine type | 1 Piston engine Napier Lion XI |
| Power, hp | 1 x 450 |
| Maximum speed, km/h | 232 |
| Cruising speed, km/h | 195 |
| Practical range, km | 801 |
| Service ceiling, m | 5837 |
| Crew | 2 |
Image gallery of the Cox-Klemin CO-1/CO-2
