Hydroplanes

The Curtiss N-9H was a seaplane version of the famous Curtiss JN-4D trainer used by the U.S. Air Service during the First World War. To make the conversion, a single large central pontoon was mounted below the fuselage, with a small float fitted under each wingtip. These changes required a 10-foot increase in wingspan to compensate for the additional weight.

During the war, 2,500 Navy pilots were trained on the N-9H. In addition to training a generation of Navy pilots, the N-9H was used to develop tactics for ship-borne aircraft operations in 1916 and 1917, using catapults mounted on armored cruisers. After the war, the airplane was again employed to successfully demonstrate a compressed air turntable catapult. In July 1917, several N-9Hs were acquired by the Sperry Gyroscope Company and were used as test vehicles for aerial torpedo experiments conducted for the Navy's Bureau of Ordnance. The N-9H was withdrawn from the U.S. Navy inventory in 1927 after ten years of exemplary service.