Experimental Wind Tunnel Models (1927)

Three carved wooden aircraft models, including an experimental tandem wing design, resting on the textured roof of the aviation factory. — Experimental Wind Tunnel Models (1927) · Donald A. Hall Estate Collection

Photographed on the roof of the factory where the Spirit of St. Louis was built, these carved wind tunnel models represent Donald A. Hall Sr.'s advanced aeronautical research in 1927. Supported by Frank Mahoney, Hall's radical tandem wing designs were later featured in Popular Mechanics and officially patented in 1933.