The first prototype, named Krylia Sovietov (Wings of the Soviets) used three French Gnome-Rhone Titan radial engines.

Mikhail Gromov accomplished a European round flight on the route Moscow – Travemünde – Berlin – Paris – Rome – Marseille – London – Paris – Berlin – Warsaw – Moscow with the Krylia Sovietov, which lasted from 10 July to 8 August 1929 and generated considerable publicity.

It carried eight passengers over a distance of 9,037 km (5,615 mi), in 53 flying hours with an average speed of 177 km/h (110 mph).

Up to the beginning of the German invasion of the Soviet Union, they served as passenger or staff airplanes mainly on routes in Central Asia and the Caucasus.

[citation needed] One PS-9 was modified into a propaganda aircraft named Krokodil (Crocodile) with a reptile-like plywood nose.