Drawing by Tapani Tuomanen

Images of R-5 SSS (Skorostnoj, Skoropodemnij, Skorostrelnij: High speed, high ascensional rate, high fire rate) in the Kiev military district, 1936.

According to some sources, the plane was designed SSS only , but the designation R-5SSS is utilized by M.Maslov on his monograph.

This was an improved plane built for ground attack role.

The main differences compared to usual R-5 were:

• more powerful engine M-17F instead of M-17;
• lightened construction with smaller oleo-pneumatic shock absorbers;
• improved aerodynamics with wing-fuselage fairings, wheels fairings;
• intakes under the nose removed;
• the gun installation on the photo looks a single Degtjarev, but it is said to have had different turrets with ShKAS;
• armed with 4 ShKAS machine guns in lower wings; some planes appear to have guns lodged into a drop-like fairing protruding on each upper surface, but this is not the case of the planes on these photos;
• internal bomb bay under the cockpit floor, aside 2 bomb racks under each lower wing.
  
  

Image from Armada n.22, Polikarpov RI-5 and R-z of Maslov

http://www.network54.com/Forum/394728/thread/1299531689/There+were+no+Polikarpov+R-5+in+Spain!