The French Salmson concern was founded in 1890 by Emile Salmson and produced a variety of automobiles prior to World War 1. Just prior to the war, Salmson turned to manufacture of aero engines and this continued throughout the conflict, well into the 1940s. Before the company went defunct in 1946, Salmson undertook various design and production initiatives regarding military-grade aircraft - among these being the "Salmson 2" biplane series of World War 1 fame.
The Salmson 2 was developed to a French Air Force requirement for a reconnaissance-minded platform intended to supplant the outgoing Sopwith 1 1/2 Strutter and Dorand A.R. series in the same role. To this, Salmson developed a highly conventional biplane arrangement with a roughly streamlined fuselage mounting the engine at the front and a crew of two seated inline in separated, open-air cockpits. The wings sported equal span assemblies with parallel support struts and applicable cabling throughout. The empennage was traditional with a single vertical tail fin and associated horizontal tailplanes. The undercarriage was a fixed assembly of struts tied to the underside of the fuselage and lower wing assembly, sporting a pair of landing wheels. A simple tail skid assisted the rear of the aircraft when at rest.
As Salmson already held an established history of aero engine production, the Salmson 2 design made proper use of the in-house Salmson 9Za series radial piston engine outputting 230 horsepower and powering a wooden two-bladed propeller assembly. This supplied the completed airframe with a maximum speed of 116 miles per hour with a range out to 300 miles. The aircraft's service ceiling was listed at a useful 20,500 feet.
Consistent with other evolved designs of the war, the Salmson 2 showcased several machine guns for which to take to the offensive or defensive as the situation in the air permitted. The pilot managed a single 0.303 caliber Vickers machine gun mated to an interrupter gear controlling the propeller. This arrangement allowed for the firing of the machine gun through the spinning propeller blades without harm to the aircraft - a technology first perfected by the Germans in the war. The rear crewman - considered an observer in the reconnaissance role and gunner in the defensive role - managed a pair of 0.303 caliber Lewis machine guns on a trainable mount. His primary role was in defense of the critical rear quadrants of the aircraft as this was where pursuing intercepting enemy aircraft would most likely originate from.
Development of the Salmson 2 occurred in 1916 to which the aircraft was formally readied for its late-1917 introduction. Production eventually steadied to provide healthy, useful wartime numbers and some 3,200 units were completed in all. The Salmson 2 proved critical to French airborne operations in the final year of the war (1918) and its importance was exemplified in the production tally. Additionally, Arriving American forces were given the mount to the tune of 700 examples for their own reconnaissance purposes - further strengthening the type's overall reach and importance to the Allied war effort against the Central Powers. Salmson also provided a slightly modified trainer variant of their Salmson 2 with redundant controls for student and instructor. All told, the aircraft was a serviceable mount with a capable feel and appropriate armament and power. Several limitations in her design were common to other aircraft of the period - limited unobstructed vision from the cockpit, open-air communications between pilot and gunner and canvas-over-wood construction.
After the Armistice of November 1918, stocks of Salmson aircraft existed to the point that they could be sold off to interested allied nations in the post-war rebuilding world. Therefore, global operators emerged in Belgium, Czechoslovakia, Peru, Poland, Spain, the Soviet Union and Japan - hundreds were produced locally in Japanese factories. The series was also developed into a handful of forgotten and, ultimately, abandoned wartime variants including the strike-minded Salmson 4, the tactical reconnaissance Salmson 5 and the single-cockpit, twin-seat Salmson 7 reconnaissance platform. Some wartime Salmson 2s were, however, recovered and modified for the civilian passenger role as the "Salmson Limousine" - air travel beginning to take hold as an applicable mode of transportation in the post-war world.