Radio, Marconi, SE 1100, Felixstowe (NAF) F5L

The Felixstowe F series flying boats were a joint British and American development during the First World War. They were an outgrowth of a prewar project led by Glenn Curtiss to build a flying boat capable of a transatlantic flight. After the war began, John Cyril Porte, a former Royal Navy officer and acquaintance of Curtiss, experimented with Curtiss flying boats for the Royal Navy. The Felixstowe F-5, as with earlier Porte designs, incorporated wings and a tail unit that were essentially of Curtiss origin, but with an improved hull design that enabled the aircraft to take off more quickly under heavy load.

The Naval Aircraft Factory redesigned the Felixstowe F-5 for American production. Numerous modifications were made, including fitting 400-horsepower Liberty 12A engines. The Liberty-powered version was designated the F-5-L. The Felixstowe F-5-L was operational in the last months of the war, but made its principal contribution after, and continued in U.S. Navy service until 1928.