The Salmson-Moineau S.M.1 A3, (later re-designated Salmson Sal. 1 A3), was a French armed three-seat

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

long range

reconnaissance aircraft A reconnaissance aircraft (colloquially, a spy plane) is a military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using photography), signals intelligence, as ...

of the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

Salmson Salmson is a French engineering company. Initially a pump manufacturer, it turned to automobile and aeroplane manufacturing in the 20th century, returning to pump manufacturing in the 1960s, and re-expanded to a number of products and services ...

company.

Design and development

The S.M.1 A3 was developed from 1915 to meet the French military A3 specification, which called for a three-seat long range reconnaissance aircraft with strong defensive armament. The S.M.1 was unconventional, powered by a single Salmson 9A liquid-cooled radial engine mounted in the fuselage powering two airscrews mounted between the wings with a system of gears and drive shafts. This layout was chosen by Moineau to minimise drag. The twin airscrew layout allowed a wide field of fire for the two gunner-observers, one seated in the nose and one behind the pilot. Both gunners operated ring-mounted flexible 37 mm APX cannon built by Arsenal Puteaux. The airframe itself was relatively conventional, the boxy fuselage mounted on a system of struts between the wings. The undercarriage included a nose wheel, intended solely to prevent the aircraft nosing over, and a tail skid. One aircraft may have been fitted experimentally with a Salmson (Canton-Unne) P.9 engine. A single S.M.2 S2 aircraft, with an additional Salmson 9A engine in the nose driving a conventional tractor airscrew, was tested with poor results, due to inadequate engine cooling, in 1918.

Operational history

The aircraft was tested in early 1916 and was sufficiently successful to receive an order for 100 aircraft although the performance was inferior to the Sopwith 1½ Strutter. In service the S.M.1 was not successful. The nose-wheel undercarriage would collapse if misused and this caused many accidents. The complicated transmission system was difficult to service in the field and the performance of the aircraft was poor. It appears that around 155 S.M.1s were built in total. The type was largely withdrawn from service in 1917 but a small number of aircraft remained in use until late 1918. Some S.M.1s were supplied to the

Imperial Russian Air Service The Imperial Russian Air Service (russian: Императорскій военно-воздушный флотъ, , Emperor's Military Air Fleet) was an air force founded in 1912 for Imperial Russia."''12 августа 1912 года прик� ...

, but they were no better liked in

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

Operators

; *

French Air Force The French Air and Space Force (AAE) (french: Armée de l'air et de l'espace, ) is the air and space force of the French Armed Forces. It was the first military aviation force in history, formed in 1909 as the , a service arm of the French Army; ...

; *

Variants

;S.M.1 A3 :The production 3-seat reconnaissance aircraft, powered by a single

Salmson 9A2c The Salmson water-cooled aero-engines, produced in France by Société des Moteurs Salmson from 1908 until 1920, were a series of pioneering aero-engines: unusually combining water-cooling with the radial arrangement of their cylinders. Histor ...

radial engine laterally mounted in the fuselage driving two propellers via shafts and gearboxes. ;S.M.2 S2 :An enlarged S.M.1, for the S2 2-seater ground attack role, with extended upper wings with additional bracing, reinforced undercarriage and a second

in the nose driving a 2-bladed tractor propeller directly.

Specifications (S.M.1 A3)

Notes

References

* * * Davilla, James J., & Soltan, Arthur M., ''French Aircraft of the First World War.'' Stratford, Connecticut: Flying Machines Press, 1997. * {{Salmson aircraft 1910s French military reconnaissance aircraft Military aircraft of World War I Biplanes Salmson aircraft Single-engined tractor aircraft Aircraft first flown in 1916