Wind-tunnel Tests of the Fowler Variable-area Wing
This is a 1932 NASA technical report on wind-tunnel tests of a Fowler variable-area wing, a wing whose chord extends backward on rails to add area, issued as a government aeronautics research document for engineers and aircraft designers. The pictures are engineering line graphs plotting lift and drag coefficients against angle of attack for several flap positions, with a cross-section sketch of the wing at the top of each page; a designer might take from them only the plotted curve shapes, which are dense, technical, and unlabeled to a general eye.
