Development of the NACA slot-lip aileron
This is a 1935 NACA technical report from the NASA Technical Reports Server, presenting wind-tunnel test data on slot-lip ailerons for engineers and aeronautical researchers. The pictures are engineering line graphs of hinge-moment coefficient against aileron deflection at two angles of attack, plus a cross-section sketch of the aileron and slot geometry and a mechanical linkage diagram. A designer could take from them the clean plotting conventions of mid-century technical graphs, with thin grid lines, labelled axes and simple curve families in black ink.



