The Northrop Delta was a derivative of the Gamma mailplane, its wider fuselage seating eight passengers. It was not a success as new regulations killed single-engined airliners in the USA in 1934. This example was registered in Sweden on 19 April 1934 and the next morning, it took off for a special Stockholm - Malmö - Amsterdam - Paris flight. Note the Northrop logo on the fin. Photo from: Amsterdam City Archives

Seen in front of Schiphol's Hangar B with KLM's first DC-3, PH-ALI Ibis, the ABA Northrop Delta is wearing no titles or name at this point and it may well be that the aircraft is on its way to Spain here where it served the Republican government during the Civil War. It was finally used by Franco's air force during WWII. Photo from: Amsterdam City Archives