 Despite this effort, Durnovtsev and his crew were given only a 50% chance of surviving the test.The bomb, weighing 27 metric tons, was so large ( long by in diameter) that the Tu-95V had to have its bomb bay doors and fuselage fuel tanks removed.The bomb was attached to an , parachute, which gave the release and observer planes time to fly about away from ground zero, giving them a 50 percent chance of survival.