page_title: Thomas-Morse S-4
section_title: Operational history
hierarchical_section_title: Thomas-Morse S-4 / Operational history
caption_attribution_description: English: Thomas Morse Sv-4c Scout, 38945, at Rogers Field air show, 1918.
context_page_description: The Thomas-Morse S-4 Scout was 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.
context_section_description: The S-4B, with a100 hp (75 kW) Gnome, a span of 27’ (8.22 m), and length of 20’3” (6.17 m) proved more successful, with three prototypes followed by an order of 97 for the Army and 10 for the Navy, while six more were completed with two main and one tail floats as the Navy S-5. The S-4B was used by practically every pursuit flying school in the U.S. during 1918.
  It was supplemented in 1918 by the S-4C, at a cost of US$5400 each. Six prototypes were built, 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. 461 S-4Cs went to the Army and four S-4Cs with floats went to the Navy.
  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.
  A single aircraft was fitted with new tail and the more powerful 110 hp (82 kW) Le Rhone 9J rotary engine, becoming the S-4E aerobatic trainer. It was not adopted by the military, and after being fitted with a 135 hp (101 kW) Aeromarine V8 engine, it became Basil Rowe‘s racer Space-Eater.
  About sixty surplus aircraft survived in civil service, most of which were fitted with the Curtiss OX-5.
caption: Thomas Morse S-4C with training school number on fuselage sides
exif: {}