Sikorsky S-41

The Sikorsky S-41 was an amphibious flying boat airliner produced in the United States in the early 1930s, essentially a scaled-up monoplane version of the S-38 biplane flying boat. It had a parasol wing with two radial engines on struts between the fuselage and wing and a completely enclosed all-metal hull cabin seating 15 passengers. Pan Am flew it on routes in the Caribbean, South America and between Boston and Halifax, and the US Navy bought three as the RS-1 and took two Pan Am aircraft into service as the RS-5.