B. D. Thomas, one of the senior designers of the Curtiss 'Jenny, designed the S.4 in early 1917. It made its first flight in June, and after evaluation tests was acquired by the US Army for advanced fighter training. Engine trouble developed and the original 100-hp Gnome Monosoupape rotary engine was replaced by an 80-hp Le Rhone. This variant of the plane was known as the S.4C. A total of 500 planes was ordered, but with the Armistice the last 155 were cancelled. Only 97 were completed. The performance of the S.4 was superior to that of the 'Jenny', and it became a popular civil trainer after the war. The S.4. also known familiarly as the 'Tommy' had an illustrious career after the First World War as a film aircraft, playing British, French and German aircraft with little more than different paint jobs and tail surfaces. It appeared in Hell's Angels and Dawn Patrol.

The Thomas company was founded by a young Englishman, W. T. Thomas, who emigrated to the United States and obtained a position with Glenn Curtiss at Hammondsport, New York. He was later joined by his brother Oliver, and they set up the aircraft firm of Thomas Brothers at Hammondsport, where an experimental pusher biplane was constructed in 1910.

The firm then moved to Bath, New York, where a number of types were built; one of these gained the world's altitude record in 1913. Shortly before the outbreak of war in Europe, B. D. Thomas-no relation-joined the concern; he had worked for both the Vickers and Sopwith companies in England. His first design was the T-2 tractor biplane, twenty-four of which were supplied to the British Admiralty in 1915.

After a second move, to Ithaca, New York, the firm began to produce aero engines, one of which was installed in their next design, the D-2 tractor biplane. During 1915 two seaplanes and the D-5 landplane were built for the U.S. Navy and Signal Corps respectively; further seaplanes and a flying boat appeared in the following year.

In January 1917 the firm merged with the Morse Chain Company of Ithaca, and the concern was reorganized as the Thomas-Morse Corporation. The first Thomas-Morse aeroplane was a trim little single-seater biplane, the S-4. Its 100 h.p. Gnome Monosoupape 9-B rotary engine was partly enclosed by a circular open-fronted cowling, which was faired into the flat-sided fuselage by triangular fillets.

The staggered wings were constructed of wood, wire-braced and fabric-covered; the top plane was flat, the lower plane had slight dihedral. There was a semicircular cut-out in the trailing-edge of the top wing, which carried the ailerons; these were operated by vertical rods.

Single-bay wooden interplane struts, braced by wire, were fitted; the center section struts were slightly splayed outwards. The fuselage was a wooden wire-braced box girder, with a rounded top decking; the whole structure being covered with fabric.

The neatly shaped empennage was of wood and fabric construction. Wooden vee struts formed the undercarriage legs; the wheels were sprung with rubber cord.

As it could be easily converted into a seaplane, the S-4 was offered to both the U.S. Army and Navy. The prototype was tested at Hampton, Virginia, and as a result of these trials fifty modified machines, known as S-4Bs, were ordered shortly after the United States entered the war.

This order was increased to 150 to cope with the increased need for training aeroplanes. Meanwhile a similar model with twin floats, the S-5, was put into production for the Navy Department.

The last fifty machines ordered had shorter-span wings and were designated S-4Cs. Further orders were placed for this version, with the 80 h.p. Le Rhone 9-C rotary, built by the Union Switch and Signal Company of Swissvale, Pennsylvania, in place of the Mono-Gnome; the fuselage of the Le Rhone 'Tommy' was slightly shorter.

In all 447 Le Rhone versions were delivered, and they were widely used as advanced trainers. The final model in the series was the S-4E aerobatic trainer; it had shorter tapered wings and a mounting for a synchronized gun.

 

THE THOMAS Morse S~C was a single-seat advanced trainer of which about 600 were built. Most went to the U.S. Army Air Service but a few also went to the U.S. Navy from 1917. They were powered by the 80-hp LeRhone rotary engine and also used the 100-hp Gnome rotary in some models.

Nicknamed "Tommy", the trainer represented to student pursuit pilots all that was to be expected of a single-seat fighter by way of feel and appearance, plus a lot of gentleness that some combat types of WW I lacked. It was not considered good enough, either in performance or handling qualities to be used as a fighter. It never went overseas and was relegated to training fields during WW I.

Over 1,000 were built and, following the Armistice, were declared surplus and purchased by sportsman pilots and barnstormers during the early '20s. The busy roar of its rotary engine that had echoed from dozens of training fields all over the country during the war continued to be heard until about 1930. The motion picture industry used a great many Tommy's after that in Hollywood air epics.

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Only one S4B is left, at Cole Palen's Old Rhinebeck Aerodrome; four-C's are in museums.

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Specifications for the Thomas-Morse S-4c "Tommy"

Length: 19 ft 10 in Wingspan: 26 ft 6 in Gross weight: 1,330 lb Powerplant: 1 × Le Rhône aircooled rotary, 80 hp Performance Maximum speed: 97 mph Service ceiling: 15,000 ft

 

Thomas-Morse S-4c "Tommy" Scout crashed near Carlstrom Field.