|Type||ANT-7||R-6||R-6 pre- prod.||R-6 prod.|
|Function||Multi-role combat aircraft|
|Weights (kg) and Loads|
|Wing Load (kg/m2)||64.7||67.6||77.6||81.0|
|Power load (kg/hp)||5.17||5.40||6.10||6.50|
|Roll (m [sec])|
|Landing||250 ||-||-||250 |
|Takeoff||120 ||-||-||160 |
|Turn time (sec)||19||-||23||23>|
|Range (km) and Endurance|
Idea of heavy multi-role aircraft was very popular in many countries since 20's. Indeed, twin-engine monoplanes often were faster than contemporary biplane fighters. Large aircraft could have long range and carry strong armament, providing reliable escort for bombers and capable to perform reconnaissance (and strike) missions far behind enemy lines.
Success of TB-1 (ANT-4) provided Soviet aviation with reliable basic design, and scaled down variant was put into series production even before first flights were performed. Design stage started in October 1926, TTKh of the 'air combat aircraft' were approved in January 1928, and on September 11, 1929 first ANT-7 was ready. Originally planned 520...610hp Hispano-Suiza (or 420hp Bristol Jupiter VI) were replaced by more powerful BMW-VI, scheduled for mass production in the USSR as M-17.
After some modification of the aircraft tail R-6 was presented on State Trials (even without passing Factory Trials!) in May 1930. The first aircraft differed from following machines by retractable radiators in center wing section. All series R-6 had honeycomb radiators installed under the engines, in same nacelles.
Aircraft was armed with 5 machineguns, one gunner occupied retractable underbelly turret.
Trials of first series R-6 (started October 5, 1931) revealed dangerous vibration of tail, caused by wing generated vortex. Problem was solved by adding fixed flaps at trailing edge of the central wing section. Speed was lowered by 7...8km/h
Team of V.M.Myasichev modified cooling system on one ANT-7. radiators were moved into in-wing tunnels, with air flow exit on the upper wing surface. Eventually this modification allowed to remove fixed flaps from the wing. Aircraft speed increased by 5km/h and ceiling by 300m, but during taxi and hot weather operations engines suffered from overheat.
In 1937 P.G.Golovin flew the R-6 over the North Pole. He reconned the area, where other aircraft of The First Polar expedition landed later.
More than 400 built, in service for ~15 years.