This slide rule calculator was designed and manufactured by the Standard Aeronautical Co. of Chicago, Illinois, in 1916. It was intended to “supplement the slide rule for the special calculations involved in aeroplane design.” The instrument works based on the interdependence of a selected wing cross section and the weight, drag, and horsepower of an aircraft, producing lift coefficient, glide distance, and required horsepower.
This item first ran in the February 2020 issue of EAA Sport Aviation magazine.