On this channel, we have covered our fair share of weird, wonderful, and sometimes utterly bonkers German ‘secret weapons’ from the Second World War, from rocket-powered fighters that sometimes dissolved their pilots alive to midget submarines cobbled together from old torpedoes, piggyback bombers crammed with explosives, jet fighters designed to be flown by children, and even weaponized space shuttles. But when it comes to insanity, few weapons can compare to the Bachem Ba 349 Natter. Less a fighter jet than an antiaircraft missile with a man strapped inside, the crude, hastily-built Natter was one of many ingenious attempts to save Germany from the relentless Allied bombing campaign. This is the story of one of the most desperate weapons of the Second World War.

By 1944, German cities were being pounded to rubble by round-the-clock Allied bombing raids, with the Americans bombing by day and the British by Night. With many of its factories and airfields damaged or destroyed by the bombing and the bulk of its forces already committed to the Eastern Front, the German Air Force or Luftwaffe found itself desperately short of aircraft, fuel, and pilots, and struggling to hold off the Allied onslaught. The Nazi High Command thus turned to a variety of high-tech “wonder weapons” in a desperate attempt to stem the tide. These weapons included the Messerschmitt Me-262 Schwalbe, the world’s first operational jet fighter; the rocket-powered Messerschmitt Me-163 Komet; and guided surface-to-air missiles like the Rheintochter, Enzian, Schmetterling, and Wasserfall. However, none of these advanced weapons came close to solving the problem – for a variety of reasons. As covered in our previous video The German Rocket Fighter That Dissolved Its Pilots Alive, while the Komet was faster than any contemporary Allied fighter aircraft, the fuels used by its engine were extremely volatile and had a tendency to blow up – or, as the title of that video suggests, dissolve its pilots – during rough landings. It also had an extremely short endurance, forcing Komet squadrons to be stationed close to the targets they were protecting and the aircraft to glide to a landing once their fuel ran out. This made the aircraft extremely vulnerable. The very same problem afflicted the Me-262 jet fighter, with the majority being shot down by marauding Allied fighters as they came in for a landing. Meanwhile, while Germany’s various guided missile projects showed promise, they were too complex and developed too hastily and too late to become viable weapons by the time the war ended. They were also developed separately by different branches of the German armed forces, leading to wasteful duplication of effort and competition for scarce resources. But what truly doomed these projects was the large quantities of raw materials and manpower they required to produce – resources Germany was swiftly running out of. So, on September 10, 1944, the German Air Ministry or RLM issued a set of requirements for an “Emergency Fighter” that could be produced in large numbers using non-strategic materials and semi-skilled labour and flown by pilots with only minimal training. One design to come out of these requirements was the Heinkel He-162 Volksjager or “people’s fighter”, which we have already covered in our previous video The Jet the Nazis Designed to be Flown by Children. But a far more radical was a concept submitted by engineer Erich Bachem of Fieseler Aircraft Works in Kassel.

38 years old at the time, Fieseler had until 1942 been the technical director of Fieseler, where he had contributed to the design of the highly-successful Fi 156 Storch military liaison aircraft. In February 1942, however, he left the company to form Bachem-Werke GmbH, an aircraft parts supplier based in Waldsee. Bachem’s submission for the Emergency Fighter Program neatly solved most of the issues which had plagued previous air defence weapons, such as the need for vulnerable runways for takeoff and landing; and the need for sophisticated automatic guidance systems. Instead of taking off from a runway, Bachem’s rocket-powered fighter was launched vertically from a tower like a missile, though unlike a missile it was guided to its target by a human pilot. After completing its mission the craft, which had no landing gear, simply split apart, with the pilot and the expensive rocket engine parachuting back to earth to be reused for a future mission.

A similar design had been proposed by Wernher von Braun, designer of the infamous V-2 ballistic missile, back in 1939, but this had been rejected by the RLM. And despite Germany’s desperate situation and the many advantages of Bachem’s design, it too was turned down in favour of the more conventional Heinkel P.1077 proposal. Undeterred, Bachem sought the help of decorated Luftwaffe ace and General Adolf Galland to push through his design, but once again the RLM was uninterested. Thankfully, however, the inter-service rivalry rampant in Nazi Germany soon came to Bachem’s rescue as his design caught the attention of Reichsführer Heinrich Himmler, head of the SS. Impressed by the proposal, Himmler signed an order to build 150 aircraft using SS funds, tapping SS-Obergruppenführer Hans Kammler to head the development effort. Kammler had already played a leading role in another secret weapons program, creating the infamous Mittelwerk underground factory at Nordhausen, where V-2 ballistic missiles were built using slave labour. Indeed, Kammler proposed a similar arrangement for producing this new interceptor, but Erich Bachem vehemently opposed this suggestion. Meanwhile, realizing that the SS was developing an aircraft outside their jurisdiction, the RLM placed their own order for 50 airframes, which they officially designated the Bachem Ba 349 Natter. And as side note, while many sources translate “Natter” as “adder” or “viper”, the term actually refers to non-venomous species such as the common European grass snake.

Measuring only 6 metres long and 4 metres wide, the Natter was a very basic aircraft, with simple, stubby rectangular wings and cruciform tail surfaces. Built mainly of wood held together with glue, the Natter could be assembled from poor-quality materials by semi-skilled labour in as little as 1000 man-hours. The craft was powered by the same Walter HWK 109-509 rocket engine as the Messerschmitt Me-163 Komet, which burned a combination of Hydrazine Hydrate and Hydrogen Peroxide fuel to produce 1140 kilograms of thrust. However, since the Natter was launched vertically, additional power was provided on takeoff by four Schmidding SG-34 strap-on solid rocket boosters producing 1,200 kilograms of thrust each. The Natter was launched from a 20-metre tall triangular launch tower which could be more easily concealed than the large runways used by the Komet, with the wings fitting into guide slots to prevent the aircraft from twisting as it rose. Once free of the tower, the Natter would be guided to its target altitude of around 6,000 metres by a simple autopilot or – as was later planned – via radio guidance from the ground. Thanks to its top speed of 1,000 kilometres an hour, the Natter would reach operational altitude in just 4.6 minutes, whereupon the controls would unlock, allowing the pilot to guide his aircraft towards the incoming allied bomber formation. At this point the main engine would have run out of propellant, turning the Natter into a high-speed glider. Once aligned with his target, the pilot would jettison the aircraft’s plastic nosecone to reveal the main armament: a battery of nineteen Heber R4M 55mm Orkan or twenty-four 73mm Henschel Hs 297 Föhn unguided rockets. These weapons – when they actually managed to hit their targets – were highly effective, with one Me-262 pilot describing their effects as:

“Shattered fuselages, broken-off wings, ripped-out engines, shards of aluminium and fragments of every size whirled through the air. It looked as if someone had emptied out an ashtray.”

It was also proposed to arm the Natter with the same 30mm MK 108 autocannon as the Me-262 and even a concrete nose for use in ramming attack, though Erich Bachem vehemently nixed the latter proposal, insisting that his design was not a suicide weapon. Indeed, the Natter’s pilot was provided with a steel armour plate behind his seat and an armoured windscreen to increase his chances of surviving a mission.

Once his main armament was expended, the Natter pilot would quickly descend to an altitude of around 3,000 metres, flatten out his glide slope, and initiate the escape sequence. This involved the pilot unlatching his harness, jettisoning the canopy, and releasing a lock at the base of his control column. This allowed him to tilt the column forward and unlock the nose release mechanism. He would then pull another lever on the cockpit floor to release the nose, which would be pulled free of the fuselage by aerodynamic forces. This, in turn, would deploy a small ribbon parachute from the fuselage, pulling it away and throwing the pilot forward via inertia. Once clear of the aircraft, the pilot would open his own parachute and descend to the ground, while the rear fuselage parachuted separately for eventual recovery and reuse. Each mission would take less than 10 minutes from start to finish, with the Natter having an operation radius of around 12 kilometres – enough to defend a single factory or other strategic site. This made the Natter a form of point defence interceptor – a role now largely filled by unmanned guided missiles.

Wind-tunnel tests conducted at the Institute for Aerodynamics for Berlin in September 1944 revealed the design to be stable at speeds of up to 500 kilometres per hour, allowing preliminary development to proceed as planned. The first prototype, designated M1, was manufactured at Bachem’s new factory at Waldsee in the Black Forest and delivered in October 1944. Fitted with temporary landing gear and towed behind a Heinkel He 111 bomber, the aircraft was used for a series of captive glide tests. While the first four flights went perfectly, during the fourth the Natter became unstable, forcing test pilot Erich Klöckner to bail out. When it was determined that the tow cable and temporary landing gear had interfered with the craft’s aerodynamics, pilot Hans Zübert made a daring untethered gliding flight to prove the design once and for all. The aircraft performed perfectly, allowing the project to proceed with powered flights.

The first vertical, unmanned launch of the Natter took place on December 18, 1944 at Ochsenkopf near Württemburg. As the Walter rocket engines were not yet ready, the aircraft was powered only by the Schmidding boosters. Unfortunately, due to a design flaw in the launch tower, the aircraft crashed soon after liftoff. The next launch on December 22, however, was completely successful, as were the next 10 launches. In early 1945, the Walter engines finally arrived, and a full-up test launch with all engines and a dummy pilot was conducted on February 25. Once again the launch went perfectly, with the dummy being recovered intact. However, the residual propellants in the engine exploded on impact with the ground, destroying the rear fuselage.

Though Erich Bachem pushed for further unmanned tests, the SS was anxious to get the Natter into combat and ordered that a manned flight be completed as soon as possible. A 28-year-old Luftwaffe test pilot named Lothar Sieber volunteered to make the flight, which was scheduled for February March 1. The test aircraft, M23, was fitted with a radio telemetry system to record flight data and an intercom to allow Sieber to communicate with the launch bunker before launch. During the flight itself, however, Sieber would be on his own – just like the anticipated future pilots of the Natter. Just prior to launch, Erich Bachem briefed Sieber as he lay on his back in the cockpit, reassuring him that the aircraft was stable and would be easy to control should it start going off course. Minutes later, all five rocket engines ignited with a deafening screech and the Natter roared up the launch tower, making Lothar Sieber the first human in history to ride a vertically-launched rocket. This feat would not be repeated until April 12, 1961, when Soviet cosmonaut Yuri Gagarin became the first human to reach outer space. But soon after the Natter cleared the launch tower, things started going seriously wrong. At an altitude of around 150 metres, the Natter suddenly pitched up by 30 degrees and entered an inverted loop, slowly pulling back to near-horizontal before disappearing into the clouds. About 30 seconds later, the aircraft slammed into the ground a few kilometres away, killing Sieber instantly. It was later determined that the canopy latch had not been properly secured, causing the canopy to fly open and knock Sieber unconscious. The autopilot then disengaged as designed, allowing the aircraft to plunge uncontrolled to the earth. Intriguingly, data collected from the telemetry system indicated that on his way down, Sieber briefly became the first human to break the sound barrier – and for more on another Luftwaffe pilot who claimed to have accomplished the same feat and survived, check out our previous video Did a German Pilot Break the Sound Barrier 2 Years Before Chuck Yeager? on our sister channel Highlight History.

Despite this tragedy, the SS pressed on with the project, though the next – and final – 10 test launches were all unmanned. In April 1945, ten aircraft and eight pilots were earmarked for the Natter’s first operational mission, codenamed Operation Crocus. The launch towers for this operation had already been constructed at the end of February in a forest called Hasenholtz just south of Stuttgart. The first missions were scheduled to be flown on April 20 – Adolf Hitler’s birthday – but on that day the U.S. 10th Armoured Division overran the area, forcing the Natter crews to destroy their aircraft and retreat to Waldsee. 18 days later Nazi Germany surrendered, the Natter having never seen combat. Today, only one complete Natter survives at the National Air and Space Museum in Washington, D.C, captured by American troops in Piztal, Austria, in May 1945.

Though the Natter was certainly among the most creative and cost-effective of Nazi Germany’s anti-bomber weapons, even had it been introduced earlier it is doubtful it would have had any impact on the course of the war. The aircraft’s operational range was simply too small, and its immobile launch towers too vulnerable to Allied air attack. And even if German industry, stretched thin as it was, had managed to produce large numbers of Natters, Germany simply had too few trained pilots to fly them. The plain truth was that Nazi Germany had already lost the war, and like all its fellow ‘wonder weapons’, the Natter program was simply a case of too little, too late.