The initial production S.90 was a low-wing aircraft with fixed tailwheel undercarriage and side-by-side seating for two.

[1] 100 aircraft were ordered by the French government, on behalf of the aeroclubs, and these were powered by the 75 hp (56 kW) Minie 4DC engine as the SIPA S.901.

[2] In later years, the S.90 series readily found buyers in the secondhand market and examples have flown with private owners in Belgium, Germany, Switzerland and the United Kingdom.

Nine further aircraft were built later with plywood covering in lieu of fabric, receiving new designations.

The following variants were produced:[3] Data from Airlife's World Aircraft[4]General characteristics Performance