At the beginning of 1915 there appeared the prototype Curtiss Model R, which was in 1935 given the retrospective designation Model 2, an enlarged version of the Model N with equal-span staggered wings. It was flown both as a land-plane and float seaplane. Pilot and observer of this military reconnaissance biplane were housed in one long open cockpit and the Model R could be distinguished from the Model N by its inter-plane ailerons and lack of a fixed fin. The R-2 introduced unequal-span wings with ailerons attached to the upper wing, a vertical tailplane which in-corporated a fixed fin and horn-balanced rudder and there were separate and widely spaced cockpits for the two crew members. The Curtiss V-X engine of the prototype was retained. The R-2 went into production at the end of 1915 and was built in some numbers, 12 going to the US Army, making only limited use of the type. The US Army R-2s were flown in support of the expedition against the Mexican insurgent leader Pancho Villa, but although their serviceability was poor they flew a number of reconnaissance and liaison missions. The one-off R-2A was an equal-span variant and established an American domestic altitude record of 2740m, carrying pilot and three passengers, in August 1915. Two R-3 seaplanes, resembling the R-2 but with increased wing span, were brought by the US Navy in 1916.
Curtiss R-2 Engine: 1 x 119kW Curtiss V-X inline piston Take-off weight: 1403 kg / 3093 lb Loaded weight: 826 kg / 1821 lb Wingspan: 14.00 m / 45 ft 11 in Length: 11.70 m / 38 ft 5 in Wing area: 46.90 sq.m / 504.83 sq ft Max. speed: 138 km/h / 86 mph