M-4 BisonM 4 Bison airplane model. First flying soon after the first flight of the B 52 Stratofortress, the M 4 initially impressed Soviet officials, however, it soon became clear that the bomber had an insufficient range to attack the United States and still return to the Soviet Union. Only several of the original production M 4s were actually put into service. The M 4 was first displayed to the public in Red Square, on May Day, 1954. To remedy this problem,