Curtiss S-1 / Model 10 / Baby Scout / S-2 Wireless
 
 Curti-S1-01
S-1 Speed Scout
 
The Model S was Curtiss' first attempt at a fast and manoeuvrable single-seat fighter. The first variant, S-1 Speed Scout, also called Baby Scout, had disappointing performance. The first Model S of 1916 was a single-seater built to the concepts of what European builders had called a Scout in 1914. This was a single-seat tractor biplane originally used for the work its name implied - the scouting of enemy activity.
 
 Curti-S1-02
The sole Curtiss S-1 mounted on a truck for an Independence Day parade in New York City
 
The original Model S-1 was the smallest aeroplane that Curtiss could build around the 90 hp OX engine.
 
Construction was thoroughly conventional for the time, but the 20-ft (6,09 m) span of the single-bay wings was inadequate. The upper wing was lengthened and the strut arrangement was altered to two spanwise Vs. The S-1 did not sell, and Curtiss kept the modified prototype for its own use.
 
 Curti-S1-03
Model S-1 with the upper span increased and braced with diagonal struts.
 
In March 1917, new wings were attached to the S-1 fuselage and a strut arrangement that eliminated the need for wing bracing wires, hence the name Wireless, and the project was redesignated S-2.
 
S-2 Wireless - The S-2 was essentially the Model S-1 fitted with new wings and a strut arrangement that eliminated the need for wing bracing wires, hence the name Wireless. The problem of fining shock absorbers in the undercarriage when the wing struts were anchored to the ends of the cross-axle was solved by using the new Ackermann Spring wheels, which featured curved spokes made of flat spring steel that served that purpose; these wheels did not have good resistance to side loads, unfortunately, and were not widely used. First flown in the summer of 1916 and demonstrated to the press by Curtiss pilot Victor Carlstrom on 9 August 1916, the S-2 was powered by a 100hp Curtiss and achieved a top level speed of 119mph at sea level. Despite its neat appearance, the S-2 was generally conceded to be around two years behind its European contemporaries, thanks to America's isolation from the design impetus provided by wartime developments.
 
 Curti-S1-04
S-2 Wireless
 
The sole Curtiss S-2 Wireless single seat scout, seen here without its twin, broad-bladed propeller, along with the associated inner and outer spinners, the purpose of which was to funnel cooling air to the annular engine radiator revealed in this view.
 
 Curti-S1-05
S-2 Wireless
 
Gallery
 
S-2 Wireless
Powerplant: 100 hp Curtiss OXX-2
Span 21 ft 10 in (6,65 m) (upper), 11ft 3 in (3,42 m) (lower)
Aerofoil Eiffel 32
Empty Weight 805 lb (365 kg)
Maximum speed 119 mph (191,5 km/h).