During the 1920s and 1930s scores of aircraft firms around the world developed flying boats for both military and commercial roles. One that was successful, but not produced in large numbers—nor generally remembered—was the Hall PH flying boat.
Engineer Charles Ward Hall founded the Hall Aluminum Aircraft Company in 1927 in Buffalo, New York, to build all-metal aircraft for the U.S. Navy. He was the son of Charles Martin Hall, inventor of the definitive aluminum-refining process and founder of what became the Aluminum Company of America (Alcoa). The younger Hall began research into aluminum-hull flying boats with the Aeromarine firm in 1916. A decade later he designed the PH flying boat. It was derived from the long series of flying-boat designs produced by the Naval Aircraft Factory in Philadelphia, which in turn had been based on the British F.5 Felixstowe flying boat of World War I.
Although Hall produced few PH flying boats—a total of 24 for the U.S. Navy and Coast Guard—the aircraft was well liked and gave long service.