Commercial Passenger Cabin Monoplane Number 12 with Open Doors (Circa 1925)

A high-wing commercial passenger monoplane marked number 12 parked inside a hangar with three cabin doors standing open. — Commercial Passenger Cabin Monoplane Number 12 with Open Doors (Circa 1925) · Donald A. Hall Estate Collection

Illustrating the rapid evolution of passenger boarding and cabin ergonomics, Donald A. Hall Sr. documented this high-wing transport monoplane, marked with a bold number 12 on the nose, parked inside an assembly hangar. Featuring three separate access doors swung wide open along the port side for the flight crew and passengers, the aircraft represents early commercial efforts to provide comfortable, enclosed air travel that Hall later refined while engineering the Ryan B-1 Brougham.