Biplanes Over the Hall X-1 Monoplane

A formation of vintage biplanes flying low over a dirt airfield, with the experimental Hall X-1 low-wing monoplane parked in the foreground. — Biplanes Over the Hall X-1 Monoplane · Donald A. Hall Estate Collection

Several vintage biplanes fly in tight formation over Camp Kearny during secret flight tests of the experimental Hall X-1 low-wing monoplane. This striking aerial view captures the dramatic transition in aeronautical design as traditional wooden-and-fabric biplanes shared the skies with the sleek, cantilevered monoplane engineering pioneered by Donald A. Hall.