The Kharkov R-10 (KhAI-5) Nieman is a Soviet World War II-era recon and light bomber monoplane. It was very outdated by the time war broke out. The plane is very cheap, but it has to be upgraded, even in the 1939 era.
The first prototype of the plane, with a factory designation KhAI-5 (ХАИ-5), flew in June 1936. Despite a lower performance, the aircraft won a contest against another reconnaissance plane design, the Kotcherigin R-9, and was accepted for a production with the military designation R-10 ('R' stands for razvyedchik, which means reconnaissance). It was quite a modern design at that time. 493 R-10s had been manufactured in Kharkiv and Saratov aviation plants by early 1940. The first series showed some teething problems, and because of these I. Neman was arrested by the NKVD on December 11, 1938 under false accusation of sabotage and espionage.
In 1938, a variant KhAI-5bis was tested and fitted with an M-25E engine, it developed a speed of 425 km/h. In 1938, the KhAI-52 ground attack aircraft, based on the R-10, was also developed. It was fitted with an M-63 670 kW engine and armed with seven machine guns and 400 kg bombs. A production run of an experimental series of 10 aircraft was prepared, but it was cancelled after one was produced.
The aircraft entered service in the Soviet Air Force in 1937. R-10s were first used in combat in the Soviet-Japanese Battle of Khalkhin Gol in 1939. Then, they were used in the initial stage of the World War II, starting with use against Poland in the Invasion of Poland (without combat encounters) and against Finland in the Winter War (1939–1940). R-10s were next used in the first period of the German-Soviet war, following the German attack on June 22, 1941. By this time, they were outdated and suffered heavy losses, as did the rest of the Soviet Air Force. Many planes were destroyed on airfields. They were used as close reconnaissance aircraft, and, in need, also as light attack bombers. Later many were used as night bombers, to avoid losses in encounters with fighters. The remaining R-10s were withdrawn from combat service in 1943.