Lothar Sieber
Encyclopedia
Lothar Sieber was a German test pilot
who was killed in the first vertical take-off manned rocket flight, in a Bachem Ba 349
"Natter".
Before he became a test pilot for Bachem, he piloted an Arado Ar 232
in highly risky sorties. Shortly before his flight, he had become engaged to Gertrud Naudit, a Luftwaffenhelfer
. Sieber had held the rank of Second Lieutenant
but was demoted to Private
after an alcohol-related AWOL. Posthumuously he was promoted to Oberleutnant
.
Eyewitnesses reported that the main engine kept firing. Soon, the Natter reappeared vertically from the clouds and hit the ground at high speed. All eyes searched for Sieber appearing with his parachute from the clouds, but to no avail.
In 1998-1999, excavations found the remains of one of the Starthilfsraketen RATO rockets at the impact site, proving that it did not release from the fuselage of the Natter.
.
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.
Test pilot
A test pilot is an aviator who flies new and modified aircraft in specific maneuvers, known as flight test techniques or FTTs, allowing the results to be measured and the design to be evaluated....
who was killed in the first vertical take-off manned rocket flight, in a Bachem Ba 349
Bachem Ba 349
The Bachem Ba 349 Natter was a World War II German point-defence rocket powered interceptor, which was to be used in a very similar way to a manned surface-to-air missile. After vertical take-off, which eliminated the need for airfields, the majority of the flight to the Allied bombers was to be...
"Natter".
Before he became a test pilot for Bachem, he piloted an Arado Ar 232
Arado Ar 232
The Arado Ar 232 Tausendfüssler was the first truly modern cargo aircraft, designed and built in small numbers by the German firm Arado Flugzeugwerke during World War II...
in highly risky sorties. Shortly before his flight, he had become engaged to Gertrud Naudit, a Luftwaffenhelfer
Luftwaffenhelfer
Luftwaffenhelfer are terms commonly used for German students deployed as child soldiers during World War II....
. Sieber had held the rank of Second Lieutenant
Second Lieutenant
Second lieutenant is a junior commissioned officer military rank in many armed forces.- United Kingdom and Commonwealth :The rank second lieutenant was introduced throughout the British Army in 1871 to replace the rank of ensign , although it had long been used in the Royal Artillery, Royal...
but was demoted to Private
Private (rank)
A Private is a soldier of the lowest military rank .In modern military parlance, 'Private' is shortened to 'Pte' in the United Kingdom and other Commonwealth countries and to 'Pvt.' in the United States.Notably both Sir Fitzroy MacLean and Enoch Powell are examples of, rare, rapid career...
after an alcohol-related AWOL. Posthumuously he was promoted to Oberleutnant
Oberleutnant
Oberleutnant is a junior officer rank in the militaries of Germany, Switzerland and Austria. In the German Army, it dates from the early 19th century. Translated as "Senior Lieutenant", the rank is typically bestowed upon commissioned officers after five to six years of active duty...
.
The first manned rocket flight
On 1 March, at the Truppenübungsplatz Heuberg, Sieber entered the Natter Ba 349A M23 for the first manned vertical take-off of a rocket. The experienced test pilot was told to execute a half roll if the Natter should veer off course. The start worked as planned, Sieber executed the roll maneuvers as soon as the Natter changed its course. After the release of the solid fuel rocket boosters it could be seen that the canopy came off and fell to the ground while the Natter disappeared into the clouds.Eyewitnesses reported that the main engine kept firing. Soon, the Natter reappeared vertically from the clouds and hit the ground at high speed. All eyes searched for Sieber appearing with his parachute from the clouds, but to no avail.
Impact site
At the impact site, about 7 km away, a 5 m deep crater was found, and except half of a left arm and half of a left leg, only small parts were found, and later on a 14 cm long part of a skull.In 1998-1999, excavations found the remains of one of the Starthilfsraketen RATO rockets at the impact site, proving that it did not release from the fuselage of the Natter.
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 barrierSound barrier
The sound barrier, in aerodynamics, is the point at which an aircraft moves from transonic to supersonic speed. The term, which occasionally has other meanings, came into use during World War II, when a number of aircraft started to encounter the effects of compressibility, a collection of several...
.
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.
Further reading
- Horst Lommel: Der erste bemannte Raketenstart der Welt, Motorbuch Verlag, 2. Auflage 1998, ISBN 3-61301-862-4
- Horst Lommel: Vom Höhenaufklärer bis zum Raumgleiter - Geheimprojekte der DFS 1935–1945, Motorbuch Verlag, 1. Auflage 2000, ISBN 3-613-02072-6