The Twenty-Foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics
A 1929 NACA technical report documenting the Twenty-Foot Propeller Research Tunnel, an American wind tunnel facility for aeronautical testing, issued through the NASA Technical Reports Server. Its photographs show engineers and apparatus inside the test hall, with plain black-and-white documentary views of aircraft models, test rigs and a full-size aircraft mounted for wind tests. A designer might draw on them for industrial, mechanical or early aviation visuals, where the grid of tall windows, steel framing and bracing cross-members give a precise engineering structure.
