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S-4C Scout
Role advanced trainer
National origin United States
Manufacturer Thomas-Morse Aircraft
Designer Benjamin D. Thomas
First flight June 1917[1]

The Thomas-Morse S-4 Scout was an American biplane advanced trainer, operated by the Army and 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 S4B, which first appeared in the summer of 1917.[2]

Design and development

Built by Thomas-Morse Aircraft in Bath, New York in 1917, it was a compact single-seat open-cockpit biplane of equal span and a 100 hp (75 kW) Gnome rotary.[3] Designed by Benjamin D. Thomas, an Englishman (no relation),[4] formerly of the Sopwith Aviation Company,[5] the S-4 made her maiden flight in June 1917 in the hands of Paul D. Wilson.[4] Twelve went to the Navy.[4]

Operational history

A U.S. Navy S-5

The S-4B, with a 110 hp Gnome, span of 27’ (8.22 m), and length 20’3” (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][6] while six more were completed with two main and one tail floats as the Navy S-5.[3][7] The S4B 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 80 hp (60 kW) Gnome B-9 was replaced by the "more reliable" 80 hp (60 kW) Le Rhône C-9 with the fifty-second aircraft.[3][4] Four S-4Cs with floats went to the Navy, and 461 for the Army.[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 110 hp (82 kW) Le Rhône, becoming the S-4E aerobatic trainer.[3] It was not adopted, and (fitted with a 135 hp (101 kW) Aeromarine V8 engine) became Basil Rowe‘s racer Space-Eater.[4] About sixty surplus aircraft survived in civil service, most fitted with the Curtiss OX-5s.[4]


United States


  • S4C "Scout" is on display at the National Museum of the United States Air Force in Dayton, Ohio. The aircraft was donated to the Museum in March 1965 by Capt. R. W. Duff of Miami, Florida. It was later restored by Aero Mechanics High School in Detroit, Michigan. The aircraft is displayed in the Museum's Early Years gallery. Prior to this the Museum displayed the only known surviving S4B. This aircraft was on loan from Mrs. D.B. Woodard of Richland Center, Wisconsin from 1963 until 1965. Its whereabouts are currently unknown.[2]
  • One resides at Fantasy of Flight in Polk City, Florida.
  • Two S4C's, rebuilt with original metal fitting sets are currently under restoration in Kingsbury Texas. Both are powered with correct LeRhone 80 hp rotary engines. "Tommy I" has previously flown at Kingsbury and both aircraft will be flying eventually. As of April 2013 all horizontal surfaces have been restored for both aircraft and covered and fuselage work on both aircraft continues. The first restoration attempt of "Tommy II" was never completed but in the "re-restoration" new metal is being cut and formed for the forward fuselage and cockpit. It is intended that one Tommy will be marked with US WWI roundels and the other with the star and red disc insignia.
  • The Cradle of Aviation Museum in Garden City, NY, has an original S-4C once owned by Paul Kotze. They also have on exhibit an uncovered Scout fuselage, most likely from one of the prototypes, fitted with LeRhone engine and a working interrupter mechanism.

Specifications (S-4C, late production)

Data from Aerofiles, United States Navy Aircraft since 1911,[4][6]

General characteristics

  • Crew: 1
  • Length: 19 ft 10 in (6.05 m m)
  • Wingspan: 26 ft 6 in (8.08 m)
  • Height: 8 ft 1 in (2.46 m)
  • Gross weight: 1,330 lb (605 kg)
  • Powerplant: 1 × Le Rhône aircooled rotary, 80 hp (60 kW)


  • Maximum speed: 97 mph (156 km/h)
  • Endurance: 2 hours  30 min
  • Service ceiling: 15,000 ft (4,500 [8] m)


  • Optional .30 caliber Marlin machine gun
  • See also


    1. Holmes, 2005. p 52.
    2. 2.0 2.1 2.2 2.3 United States Air Force Museum 1975, p. 10.
    3. 3.0 3.1 3.2 3.3 Donald 1997, p. 875.
    4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 "Thomas." Retrieved: 8 April 2008.
    5. Angelucci 1973, p. 41.
    6. 6.0 6.1 Swanborough and Bowers 1976, p. 471.
    7. Swanborough and Bowers 1976, p. 472.
    8. Angelucci 1983, p. 85.
    • Angelucci, Enzo, Great Aeroplanes of the World. London: Hamlyn, 1973.
    • Angelucci, Enzo. The Rand McNally Encyclopedia of Military Aircraft, 1914-1980. San Diego, California: The Military Press, 1983. ISBN 0-517-41021-4.
    • Donald, David, ed. Encyclopedia of World Aircraft, p. 875, "Thomas Brothers and Thomas-Morse aircraft". Etobicoke, Ontario: Prospero Books, 1997.
    • Holmes, Tony. Jane's Vintage Aircraft Recognition Guide. London: Harper Collins, 2005. ISBN 0-00-719292-4.
    • Strnad, Frank. The Thomas Morse Scout. London: Profile Publications, 1966.
    • Swanborough, Gordon and Bowers, Peter. United States Navy Aircraft since 1911. London:Putnam, Second edition, 1976. ISBN 0-370-10054-9.
    • United States Air Force Museum. Wright-Patterson AFB, Ohio: Air Force Museum Foundation, 1975.

    External links

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