The Tupolev ANT-7 prototype was a scaled-down version of the ANT-4. First flown on 11 September 1929, it was powered by two 544kW BMW VI engines. Production began in summer 1930 as the multi-purpose R-6 for the air force, with a total of 435 built by June 1934. The KR-6 version was a long-range reconnaissance aircraft with increased fuel capacity and no bombload, and the MR-6 was a naval floatplane variant. Many late production aircraft were delivered for civil use under the designation PS-7 or P-6; modifications were minimal, including a strengthened freight floor and elimination of gunners' positions. The MP-6 was the civil floatplane version, and many P-/MP-6s and PS-7s had enclosed cockpits for Arctic use. The specially built R-6L was a one-off 'limousine' version incorporating a nine-passenger cabin.
R-6 Engine: 2 x M-17 Max take-off weight: 6470 kg / 14264 lb Empty weight: 3855 kg / 8499 lb Wingspan: 23.2 m / 76 ft 1 in Length: 15.1 m / 50 ft 6 in Height: 6.1 m / 20 ft 0 in Wing area: 80.0 sq.m / 861.11 sq ft Max. speed: 230 km/h / 143 mph Ceiling: 4900 m / 16100 ft Range: 800 km / 497 miles Armament: 3 x 7.62mm machine-guns, 500kg of bombs Crew: 3-5