The R-6 traces its roots back to early 1928 when the Soviet Air Force needed a long-range multirole aircraft.
The requirements were that it could be used for long-range transport, defensive patrolling, reconnaissance, light bombing and torpedo attack.
The next flight encountered radiator damage and an engine failure, but in spite of this, the ANT-7 passed the state acceptance tests.
Another variant was the KR-6 (KR – Kreiser Razveyedchik – cruiser reconnaissance), which had two PV-2 machine guns and a second gunner, that was later relegated to training duties.
By 1935, the R-6 was becoming obsolete, and several were transferred to Aeroflot and Avia Arktika, which used them to carry passengers and cargo in Siberia before the Great Patriotic War, designated PS-7-2M17 (the "2M17" showed that the aircraft were powered by two Mikulin M-17s), or as MP-6-2M17 if floats were attached.