Lothar Sieber - Aftermath

Aftermath

Reconstruction of the flight, which lasted 55 seconds and traveled a horizontal distance of 7 km, calculated an average speed of about 800 km/h, thus about 14 km were traveled in total. It is assumed that during the vertical drop, with the engine firing, Sieber inadvertently also became the first human to break the sound barrier.

Things went well at first, but one of the four jettisonable Schmidding boosters failed to release and the Natter got 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 heights in which allied bombers operated. The Natter probably turned on its back and flew horizontally rather than climb, thus accelerating which Sieber may have misinterpreted for 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. When the Natter left the clouds, Sieber likely noticed his situation 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.

As an experienced test pilot had failed to control the Natter, which was intended to be operated by many inexperienced pilots as an interceptor, the SS cancelled the project. The cause was officially explained as a failure of the canopy which may simply not have been properly latched before launch. Photos were altered to hide the fact that a FuG16 radio was in the cockpit, used to order Sieber not to bail out.

Sieber's remains were buried with military honors on 3 March 1945.