Complex sentence: The Salmson 9 AD was a family of air-cooled nine cylinder radial aero-engines produced in the 1930s in France by the Société des Moteurs Salmson.
Split into simpler sentences: The Salmson 9 AD was a family of air-cooled 9-cyl. Radial aero-engines produced in the 1930s in France by the Société des Moteurs Salmson.