Experimental Models on the Roof (1927)

A low-angle photograph of three experimental aircraft wind tunnel models lined up on a factory roof with distant hills in the background. — Experimental Models on the Roof (1927) · Donald A. Hall Estate Collection

A 1927 lineup of Donald A. Hall Sr.'s experimental wind tunnel models, including his groundbreaking tandem wing concepts. Photographed on the roof of the historic San Diego factory, these designs secured funding from key backers and pushed the boundaries of 1920s aerospace engineering.