The Thomas-Morse S-4 Scout is an American biplane advanced trainer, operated by the United States Army and the United States Navy. Dubbed the "Tommy" by pilots who flew it, the aircraft became the favorite single-seat training airplane produced in the U.S. during World War I. It had a long and varied career beginning with the S-4B, which first appeared in the summer of 1917.[2]
The S-4B, with a 100 hp (75 kW) Gnome, a span of 27 ft (8.23 m) (8.22 m), and length of 20 ft 3 in (6.17 m)[4] proved more successful, with three prototypes followed by an order of 97 for the Army and 10 for the Navy,[4][7] while six more were completed with two main and one tail floats as the Navy S-5.[3][8] The S-4B was used by practically every pursuit flying school in the U.S. during 1918.[2]
It was supplemented in 1918 by the S-4C, at a cost of US$5400 each.[4] Six prototypes were built,[4] and the 100 hp (75 kW) Gnome 9B-2 was replaced by the more reliable 80 hp (60 kW) Le Rhône 9C starting with the fifty-second production aircraft.[3][4] 461 S-4Cs went to the Army and four S-4Cs with floats went to the Navy.[4]
After World War I, many "Tommys" were sold as surplus to civilian flying schools, sportsman pilots, and ex-Army fliers. Many were still being used in the mid-1930s for World War I aviation movies, and several continue to exist in flying condition today.[2]
A single aircraft was fitted with new tail and the more powerful 110 hp (82 kW) Le Rhone 9J rotary engine, becoming the S-4Eaerobatic trainer.[3] It was not adopted by the military, and after being fitted with a 135 hp (101 kW) AeromarineV8 engine, it became Basil Rowe‘s racer Space-Eater.[4]
About sixty surplus aircraft survived in civil service, most of which were fitted with the Curtiss OX-5.[4]
4366 – S-4B was restored over the course of 15 years by the Ithaca Aviation Heritage Foundation in Ithaca, New York. It is made up of the fuselage of an S-4B, a top wing of a S-4C, and a reproduction bottom wing. Because this unique setup is the same as the setup used by the Tommy in the 1918 film, A Romance of the Air, it is believed to be the exact same plane as the one in the movie.[14] Restoration was completed in 2018, and on September 29, the plane took off from the Ithaca Tompkins Regional Airport and flew multiple circuits above a large crowd gathered in honor of the Tommy's 100th birthday. It then successfully landed. The pilot was Ken Cassens of Rheinbeck.[15] That makes it the only known example in the world that is in flying condition.[16] Now that the plane has flown once, there are no plans for it to fly again. Instead it will be installed in a permanent exhibit at the Ithaca Heritage Center, being constructed in the new Ithaca Heritage Center, the former Tompkins Trust building on the Ithaca Commons. The plane was previously owned by William N. Thibault, who donated it to the Ithaca Aviation Heritage Foundation.[17][18][13]
S-4B on static display at the National Museum of the Marine Corps in Triangle, Virginia.[29] It was obtained in a trade with the Aeroflex Museum in 1979 and was restored by Century Aviation.[30] This aircraft has original S-4B wings mounted on a reproduction B-fuselage, which was fabricated using parts from the prototype S-4.[18]
S-4C on static display at the National Naval Aviation Museum in Pensacola, Florida. In 2000, it was reconfigured as an S-5 floatplane with the addition of twin floats. It is painted as Bureau Number A-5858.[31]