Slotted-Wing Airplanes
This is a 1927 NASA technical report on slotted-wing airplanes, issued through the NASA Technical Reports Server and aimed at aeronautical engineers. The pictures are plain engineering charts and a line drawing: lift and drag coefficient graphs with plotted curves and grid lines, a moment coefficient plot, and a schematic of airflow over an airfoil with a slot. A designer could take from them the clean, labeled graph style and the simple flow-line diagram as models for technical explanation.
