Completed Hall X-1 Prototype on Airfield Beneath Military Formation Flyover (Circa 1929)

The completed Hall X-1 tandem-wing prototype parked on an airfield beside a roadster as an eight-plane military biplane formation flies overhead. — Completed Hall X-1 Prototype on Airfield Beneath Military Formation Flyover (Circa 1929) · Donald A. Hall Estate Collection

A crowning historical document of Donald A. Hall Sr.'s private aeronautical development, this negative captures his completed, fabric-covered Hall X-1 prototype parked on a Southern California airfield. The aircraft's aft fuselage shows an open tandem cockpit with padded leather coamings, tail registration markings ending in 621, and a sandbag securing the aft wing. Parked alongside a custom roadster, the aircraft sits on the runway apron as an eight-plane military biplane formation passes overhead in dual V-formations, marking a pivotal flight evaluation of Hall's patented tandem-wing design.