The United States Army Air Corps Type A back pack parachute was the first standardized model accepted by the military. It was designed and tested by the Engineering Division of the Air Service at McCook Field, Ohio. Les Irvin made the first jump with this type of parachute on April 28, 1919. Two months later, he founded the Irving Air Chute Company. The "G" was added to the company name because of a typographical error by the recording stenographer and it was never corrected. By 1939, Irving was the largest single manufacture of parachutes in the world.