Cox-Klemin CO-1/CO-2

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