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 a vertical take - off , which eliminated the need for airfields , the majority of the flight to the Allied bombers was to be controlled by an autopilot . The primary mission of the relatively untrained pilot , was to aim the aircraft at its target bomber and fire its armament of rockets . The pilot and the fuselage containing the rocket motor would then land under separate parachutes , while the nose section was disposable . The only manned vertical take - off flight on 1 March 1945 ended in the death of the test pilot , Lothar Sieber . Development . In 1943 with " Luftwaffe " air superiority being challenged by the Allies over the " Reich " , radical innovations were required to overcome the crisis . Surface - to - air missiles appeared to be a promising approach to counter the Allied strategic bombing offensive ; a variety of projects were started , but invariably problems with the guidance and homing systems prevented any of these from attaining operational status . Providing the missile with a pilot , who could operate a weapon during the brief terminal approach phase , offered a solution . Submissions for a simple target defence interceptor were requested by the " Luftwaffe " in early 1944 under the umbrella of the " Emergency Fighter Program " . A number of simple designs were proposed , including the Heinkel P . 1077 " Julia " , in which the pilot lay prone ( on his stomach ) , to reduce the frontal area . The " Julia " was the front - runner for the contract . The initial plan was to launch the aircraft vertically , but this concept was later changed to a conventional horizontal take - off from a tricycle - wheeled trolley , similar to that used by the first eight prototypes of the Arado Ar 234 jet reconnaissance bomber . Bachem ' s proposal . Erich Bachem ' s BP - 20 ( " Natter " ) was a development from a design he had worked on at Fieseler , the Fi 166 concept , but considerably more radical than the other submissions . It was built using glued and nailed wooden parts with an armour - plated bulkhead and bulletproof glass windshield at the front of the cockpit . The initial plan was to power the machine with a Walter HWK 109 - 509 A2 rocket motor ; however , only the 109 - 509 A1 unit was available as used in the Me 163 rocket aircraft . It had a sea level thrust of 1 , 700 kg . thrust with its quartet of Schmidding SG34 solid fuel rocket boosters used in its vertical launch to provide an additional thrust of 1 , 200 × 4 = 4 , 800 kg for 10 seconds before they burned out and were jettisoned . The experimental prototypes slid up a 20 m high vertical steel launch tower for a maximum sliding length of 17 m in three guideways , one for each wing tip and one for the lower tip of the ventral tail fin . By the time the aircraft left the tower it was hoped that it would have achieved sufficient speed to allow its aerodynamic surfaces to provide stable flight . Under operational conditions once the Natter had left the launcher , it would be guided to the proximity of the Allied bombers by an autopilot with the possibility of an added beam guidance similar to that used in some V - 2 rocket launches . Only then would the pilot take control , aim and fire the armament , which was originally proposed to be a salvo of 19 R4M rockets . Later , 28 R4Ms were suggested , with another source stating that the similar Henschel Hs 297 " Föhn " unguided rocket was meant to be used in the nose - mounted launch tubes . The Natter was intended to fly up and over the bombers , by which time its Walter motor would probably be out of propellant . Following its one - time attack with its rockets , the pilot would dive his Natter , now effectively a glider , to an altitude of around 3 , 000 m , flatten out , release the nose of the Natter and a small braking parachute from the rear fuselage . The fuselage would decelerate and the pilot would be ejected forwards by his own inertia and land by means of a personal parachute . In an early proposal in August 1944 , the Natter design had a concrete nose ; it was suggested that the machine might ram a bomber , but this proposal was subsequently withdrawn in later Project Natter outlines . Bachem stated clearly in the initial proposal that the Natter was not a suicide weapon and much effort went into designing safety features for the pilot . However , owing to the potential dangers for the pilot inherent in the operation of this precarious aircraft , the Natter is sometimes listed as a suicide craft . The design had one decisive advantage over its competitors – it eliminated the necessity to land an unpowered gliding machine at an airbase , which , as the history of the Me 163 rocket aircraft had clearly demonstrated , made an aircraft extremely vulnerable to attack by Allied fighters . Modifications . Bachem ' s design caught the eye of Heinrich Himmler . The " Reichsführer - SS " granted Bachem an interview and fully supported the project . In the middle of September 1944 the Technical Office of the " Waffen - SS " made an order for Bachem to develop and manufacture the Natter at his Waldsee factory . In December 1944 the project came largely under the control of the SS and Hans Kammler . This decision is said to have been the only time the SS significantly interfered with aircraft design and air fighting strategy . Early - on in the project , the " Reichsluftfahrtministerium " ( " RLM " ) undertook an engineering assessment of the Natter , which it reported on 28 October 1944 . Various stringent economies were imposed on an already frugal design . The Natter had no landing gear , which saved weight , expense and construction time . Consequently one of the most unusual features of the machine was the escape of the pilot and recovery of the machine . The proposed sequence of these events was as follows : After the attack , the Natter might dive to a lower altitude and flatten out into level flight . The pilot would proceed with a well - practised escape sequence . He would then open the cockpit canopy latch ; the canopy flicking backwards on its hinge in the airstream ; he would undo his seat belt and remove his feet from the rudder pedal stirrups . By squeezing a lever mounted on the control column , he would release a lock at the base of the column , which would allow him to tilt the column forwards where it could engage in and undo a safety latch for the nose release mechanism . He would then lean a little further forward and pull a lever hinged near the floor at the front of the cockpit . This action frees the nose section , which flies off as a result of the reduced aerodynamic pressure at the front of the fuselage . As the nose section separates , it was intended to briefly pull on two cables that release a small ribbon parachute stored on the starboard side of the rear fuselage . The parachute subsequently opens and decelerates the Natter . The pilot would be ejected from the cockpit by his own inertia and as soon as he is clear of the fuselage , he would open his personal parachute and descend to the ground . Although it was originally planned to recover the Walter liquid propulsion unit , which was probably the most expensive single component of the machine , using two salvage parachutes , associated problems were still not fully resolved prior to the war ' s end . Professor Wilhelm Fuchs reportedly calculated the Natter ' s aerodynamics at the " Technische Hochschule " , Aachen using a large analog computer . Wind tunnel testing on a wooden model , scaled to 40 % of full size , was performed at the " Deutsche Versuchsanstalt für Luftfahrt " ( DVL ) , the Institute for Aerodynamics at Berlin - Adlershof in September 1944 at speeds up to 504 km / h . Results from these tests were reported in January 1945 to the Bachem - Werk . Further model tests were carried out at " Luftfahrtforschungsanstalt Hermann Göring " ( LFA ) , Braunschweig at speeds close to Mach 1 . In March the Bachem - Werk simply received a statement that satisfactory flying qualities should be expected with speeds up to 1 , 100 km / h . Testing . Construction of the first experimental prototype " Natter , Versuchsmuster 1 " , was completed on 4 October 1944 . V1 was subsequently referred to as " Baumuster1 " ( " BM1 " ) and later still the " B " was dropped and the machine became known as the M1 . Most subsequent prototypes were known by ‘ M ’ codes , as the later prototypes of the Heinkel He 162 were . Manned glider flights began on 3 November 1944 . The first glider M1 was towed to around 3 , 000 m by a Heinkel He 111 bomber with a cable ( " Tragschlepp " mode ) at Neuburg an der Donau . The pilot was Erich Klöckner , who made all four documented " Tragschlepp " flights . After carrying out the test programme of the M1 , he bailed out and the machine crashed into the ground . Unfortunately it was found that the towing cable , and in the case of the M3 , the undercarriage interfered with the flight characteristics of the gliders and consequently the results were difficult to interpret . To clear any lingering doubts about the Natter in the glider mode , Hans Zübert made a daring free flight in the M8 on the 14 February , and showed that the Natter was indeed a very good flying machine . The vertical take - off ( VTO ) trials were conducted on high ground called the Ochsenkopf at the " Truppenübungsplatz " ( military training area ) Heuberg near Stetten am kalten Markt , Würtemberg . The first successful unmanned vertical take - off from the experimental launch tower occurred on 22 December 1944 . The distance between the Bachem factory at Waldsee and the Heuberg test site was approximately 60 km . The test machine , the M16 , was powered by four solid boosters only , without the Walter motor , as were all the early VTO trials . Up to and including 1 March 1945 , 16 prototypes had been used , eight in glider trials and eight in VTO trials . Manned VTO test flight . By January 1945 Bachem was under pressure from the authorities in Berlin to carry out a manned VTO flight by the end of February . On 25 February a M22 was in the experimental launch tower . It was as complete an operational machine as possible with the Walter HWK 109 - 509 A1 motor installed for the first time . A dummy pilot was in the cockpit . Lift - off from the tower was perfect . The engineers and ground crew watched spellbound as the M22 ascended under the combined power of the four Schmidding boosters and the Walter motor , an estimated total thrust of 6 , 500 kg ( 64 kN or 14 , 330 lbs ) . The nose separated as programmed and the dummy pilot descended " safely " under its personal parachute . The remainder of the fuselage came down under its two large salvage parachutes , but when it hit the ground the residual propellant exploded and the machine was destroyed . Despite Bachem ’ s concerns that the test programme had been significantly cut short , a young volunteer " Luftwaffe " test pilot , Lothar Sieber , climbed into the cockpit of the fully fuelled M23 on 1 March . The aircraft was equipped with an FM transmitter for the purpose of transmitting flight data from various monitoring sensors in the machine . A hard wire intercom appears to have been provided between Sieber and the engineers in the launch bunker using a system similar to that used in the manned glider flights . Around 1100 am , the M23 was ready for take - off . Low stratus clouds lay over the Ocksenkopf . The Walter motor built up to full thrust and Sieber pushed the button to ignite the four solid boosters . With a roar , the M23 rose out of a cloud of steam and rocket smoke straight up , displaying its camouflage paintwork . At an altitude of about , the Natter suddenly pitched backwards into an inverted curved flight . Initially it climbed at about 30° to the vertical . At about the cockpit canopy was seen to fly off . The Natter continued to climb at high speed at an angle of 15° from the horizontal and disappeared into the clouds . The Walter motor stalled at this time , about 15 seconds after take - off . It is estimated that the Natter reached , at which point it nose - dived and hit the ground with great force about 32 seconds later , some kilometres from the launch site . Unknown at the time , one of the Schmidding boosters failed to jettison and its remains were dug up at the crash site in 1998 . Bachem surmised that Sieber had involuntarily pulled back on the control column under the effect of the 3 G acceleration . Examination of the canopy , which fell near the launch site , showed that the tip of the latch was bent , suggesting that it may not have been in the fully closed position at launch . The pilot ’ s headrest had been attached to the underside of the canopy and as the canopy flew off the pilot ’ s head would have snapped back suddenly about , hitting the solid wooden rear upper cockpit bulkhead , and either knocking Sieber unconscious or breaking his neck . This tragedy reinforced Bachem ' s long held belief that the take - off and flight in the vicinity of the target bombers should be fully automated . The canopy latch was strengthened and the headrest was attached to the backboard of the cockpit . Before the introduction of the autopilot in the test programme , the control column would have a temporary locking device on it , which would allow the machine to ascend vertically to at least 1 , 000 m and then be removed by the pilot . The Walter motor probably ceased operation because the Natter was virtually upside - down and air may have entered the intake pipes in the propellant tanks starving the motor . Sieber had become the first man to take off vertically from the ground under pure rocket power , years before the flights of Yuri Gagarin and Alan Shepard ; if one discounts the ancient legend of the equally ill - fated flight of Wan Hu . Production . Much debate has surrounded the number of Natters built at the Bachem - Werk and their disposition . According to Bachem 36 , " Natters " were produced at the Bachem - Werk in Waldsee by the end of the war . Up to April 1945 , 17 aircraft had been used in unmanned trials comprising five gliders , all slung under an He 111 in the " Mistelschlepp " configuration prior to launch , and 12 VTO examples . Five aircraft were prepared for manned trials , four gliders and one VTO version . The M3 was flown twice , and then rebuilt at which time it was given the new code BM3a but was never flown . The total number of launches to early April 1945 was 22 , as was the total number of Natters constructed up to that time . Bachem reported further that there were 14 more finished or almost finished aircraft in April 1945 . Four of these were prototype A1 operational Natters built for test launching from a wooden pole launcher , which had been designed for field deployment . This new launcher was also constructed on the Heuberg , not far from the experimental steel tower . There is documentary evidence for two pole launches in April but not three as claimed by Bachem in his post - war presentation . The documentation for this third flight may have been destroyed by the SS at war ’ s end . Ten A1 operational Natters , called " K - Maschinen " , were constructed for the " Krokus - Einsatz " ( " Operation Crocus " ) . The fate of these 14 A1 Natters was as follows : Three were fired from the pole launcher according to Bachem , four were burnt at Waldsee , two were burnt at " Lager " Schlatt , Oetztal , Austria , four were captured by US troops at Sankt Leonhard im Pitztal , Austria and one , which had been sent as a sample model to a new factory in Thuringia , was captured by the Red Army . Consequently , the total of 36 test and operational aircraft constructed at the Bachem - Werk can be accounted for . However , Natter carcasses were used for a variety of ground based purposes ; for example , as a static booster rocket , armament and strength testing and pilot seat position tests . Some fuselages were reused after flight testing ; for example , the M5 , 6 and 7 . Of the four Natters captured at Sankt Leonhard im Pitztal , two went to the United States . Only one original Natter built in Germany in the Second World War survives in storage at the Paul E . Garber Preservation , Restoration , and Storage Facility in Suitland , Maryland , under the auspices of the Smithsonian Institution . The fate of the other Natter brought to the US is unknown . There is no documentary evidence that a Natter was ever flown from Muroc Field . The tail section of one of the Natters at Sankt Leonhard im Pitztal was broken off while it still rested on its trailer . The remaining machine was possibly destroyed when the CIOS Field Team left the area . Despite being promised one of these Natters , there is no evidence that a machine ever reached UK shores . Stability . In early February 1945 the positions of the centre of gravity for the A1 operational machine during its flight profile were giving the RLM and the SS cause for concern . They wanted these figures to be decided upon for the upcoming construction of the A1 aircraft for " Krokus - Einsatz " ( Operation Crocus ) , the field deployment of the Natter . The position of the centre of gravity is expressed as a percentage of the chord ( distance between the leading and trailing edges ) of the main wing . Thus 0 % is the leading edge and 100 % is the trailing edge . In the manned glider trials the centre of gravity had been varied between 20 and 34 % . At a meeting of engineers held on 8 February , the variations in the centre of gravity expected in the A1 " Krokus " machine were discussed . At take - off with the weight of the four solid boosters , the centre of gravity would be brought back to 65 % , but after releasing these rockets it would move forwards to 22 % . The free flight by Zübert on 14 February had showed unequivocally that the little Natter had excellent flying characteristics as a glider . The centre of gravity problem was solved initially by the addition of one metre square auxiliary tailfins that were released simultaneously with the jettisoning of the boosters . The " Krokus " aircraft had vanes that would direct the Walter rocket exhaust gases so as to assist vehicle stabilisation at low speed similar to those used in the V - 2 rocket . Legacy . French forces had captured Waldsee by 25 April 1945 and presumably took control of the Bachem - Werk . Shortly before the French troops arrived , a group of Bachem - Werk personnel set out for Austria with five A1 Natters on trailers . At Bad Wörishofen , the group waited for another squad retreating from Nabern unter Teck with one completed Natter . Both groups then set out for the Austrian Alps . One group with two Natters ended up at the junction of the river Inn and one of its tributaries , the Ötztaler Ache , at Camp Schlatt . The other group went to St . Leonhard im Pitztal with four aircraft . US troops captured the first group at Camp Schlatt around 4 May and the second group on the following day . At some time during the project , the Bachem - Werk was ordered to give complete details of the BP - 20 Natter to the Japanese , but there was doubt over whether they had received them . They were , however , known to have a general knowledge of the Natter and showed considerable interest in the project . " Operation Krokus " launch pads at Hasenholz wood . An operational launch site for the first Ba 349A - 1 operational Natters under the code name Operation " Krokus " was being established in a small wooded area called Hasenholz , south of the Stuttgart to Munich autobahn and to the east of Nabern unter Teck . Around the end of February and the beginning of March the Todt Organisation was in action , constructing each set of the trios of concrete foundations ( or " footings " ) for the launch towers . These three launch pads and their towers were arranged at the corners of an equilateral triangle , 120 m per side . The specific locations are said to be , and . In the centre of each of the three concrete footings is a square hole approximately 50 centimeters deep , which once served as the foundation for the launch tower . Beside each hole is a pipe , cut off at ground level , which was probably once a cable pit . These three concrete pads were noticed by a surveyor in the autumn of 1945 , but not rediscovered until 1999 . In March 1945 eight pilots , who were experienced , mostly highly decorated and volunteers for the first operational flights , started training at the Heuberg . This training continued until the first half of April at which time they moved to the Hasenholz operational area . The first three manned and fully armed A1 " Krokus " examples were scheduled to be launched from 20 April , which was Hitler ’ s birthday . But on that day the US 10th Armored Division drove its tanks into Kirchheim unter Teck to the northwest of Hasenholz wood . The next day it crossed the autobahn and headed straight for the Natter operational area . The Natter group subsequently retreated to Waldsee . Survivor and reproductions . Only one original A1 Natter survives ; it is stored in the Paul E . Garber Preservation , Restoration , and Storage Facility in Suitland , Maryland , USA . The evidence supports the proposition that this machine was captured at St . Leonhard im Pitztal , Austria in May 1945 by US troops . It is in a poor state of repair and is no longer accessible to the general public . The Natter displayed at the Deutsches Museum is said to have been reconstructed partly from sub - assemblies that survived the end of the war . This machine is of the experimental type as launched from the steel tower and is painted to look like an M17 . There are several static reproductions of Natters around the world , for example at the Planes of Fame Air Museum , Chino , California and Fantasy of Flight , Polk City , Florida , USA .