When the United States entered World War I, the Army’s Technical Advisory Board committed to an ambitious aviation production program. The program involved establishment of a dedicated military aeronautical research and development facility to be operated by the newly formed Engineering Division of the United States Army Air Service at McCook Field in Dayton.

The propeller unit was the first Engineering Division branch to open at McCook in December 1917. It dealt with enhancing the efficiency and durability of propellers for military aircraft. Because the goal for the propeller program was approval for service use, testing ensured that contractors manufactured products according to predetermined specifications. The type of construction, materials including wood laminates and glue, and finish could be evaluated.

This propeller was used on the Lepère, a French designed U.S. Army World War I fighter built by in America by Packard. Very few of the Liberty powered aircraft were manufactured before the war ended.