Things went well at first, but one of the four jettisonable Schmidding boosters failed to release and the Natter went out of control. At 500 m (1,600 ft) the cockpit canopy pulled off as Sieber intended to bail out. He was instructed by radio to keep trying to shake off the booster, but inside the clouds he lost orientation as he presumably did not rely on the automatic radio guiding system which was designed to lead Natters with inexperienced pilots to the altitudes at which Allied bombers operated. The Natter probably turned on its back and flew horizontally rather than climbing, thus accelerating, which Sieber may have misinterpreted as a steep nose dive, pulling harder on the thrust rudder which made things even worse. Also, the brake parachute did not open due to the booster still being stuck. It is likely that Sieber understood his situation when the Natter left the clouds, and tried to bail out, but due to the high speed he managed only to get out with his left arm and leg before the violent impact.