1 A3), was a French armed three-seat biplane long range reconnaissance aircraft of the First World War designed by René Moineau for the Salmson company.

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 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 complicated transmission system was difficult to service in the field and the performance of the aircraft was poor.