The Tupolev Tu-156 is a soviet concept AWACS,this plane was ment to replace the Tu-126 whit a more modern and advance plane and the Tu-156 came this plane is a Hevly modified TU-154 ,only the cockpit remained the same and the all plane chances whit a normal tail,middle wing position and 4 engines under them for better speed for the range is not know but it needed to be at least 11.000km,on the roof of the plane is the circular dome for the radar ment to intercept planes at a range of 300km of distance, despite all the thing the plane never become reality due to difficulties in the buimding and a simpler plane for the role the Il-76 become the A-50 whit the same radar dome.