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Bachem Ba 349 Natter

Bachem's cheap and simple vertical launch, rocket-powered fighter

Erich Bachem had a brilliant idea.

Bachem was a creative and persistent aircraft designer in wartime Nazi Germany. His idea, the Bachem Ba 349 Natter (Adder) was a manned, vertical takeoff interceptor; a semi-disposable aircraft intended to wield 24 nose-mounted Henschel Hs 217 73 mm air-to-air rockets or 33 of the smaller 55 mm R4M rockets against Allied bombers. Today, the Natter might be called a surface-to-air missile with a cockpit. Today, as well, because we know how things turned out, Bachem’s Natter might be called a brilliant mistake.

After Luftwaffe officials looked at his blueprints and dismissed Bachem’s concept, he bravely sought an appointment with Reichsführer-SS (Schutzstaffel, or “Protection Squadron”) Heinrich Himmler. Himmler was a man who had a temper and who could have anyone killed on a whim. One of the most powerful men in the Reich, an architect of the Holocaust, the deceptively bookish Himmler was a man to be feared. You did not get an audience with Himmler easily, and you did not want to make a mistake in his presence.

Fighting the Natter would have been difficult for P-51 Mustang pilots and near impossible for gunners aboard B-17 Flying Fortress and B-24 Liberator bombers. The Natter was designed to hit and run. With stubby little wings spanning less than a dozen feet, it was a very small target, and pushed through the sky by rocket power, it was exceedingly fast. Bachem’s rocket-armed aircraft was in many ways more like an artillery shell than a fighter plane.

But Bachem was desperate. He had a military solution to what he saw as the Reich’s military problems and military men, including key leaders of the Luftwaffe, had rejected him. He believed his aircraft could defeat the four-engined Allied heavy bombers that were increasingly plentiful in Germany’s skies.

 

Dumb Rockets

The idea of mounting an air-to-air defense using an aircraft carrying “dumb” rocket projectiles has recurred throughout air warfare history. Allied “balloon busters,” for example, had used primitive Le Prieur rockets to down German observation balloons during World War I. Long after Bachem had the idea, the U.S. heartland was defended in the 1950s by fighter interceptors that carried only 2.75 mm air-to-air rocket projectiles, twenty-four in the case of the F-86D Sabre, no fewer than 104 in the F-89D Scorpion and 48 in the F-94C Starfire. But the Sabre, Scorpion and Starfire were costly, complicated warplanes designed to return from a mission to fight another day. The aircraft taking shape in Bachem’s engineering drawings was cheap and expendable. The aircraft did not need to survive a mission, and it appears little concern was directed toward whether the pilot did, either.

Fighting Hitler's Jets

This article about the Bachem Ba 349 Natter is adapted from the book “Fighting Hitler’s Jets” by Robert F. Dorr, to be published in September by Zenith Press.

Thirty-four years old, credited with being a co-designer of the Feiesler Fi 156 Storch (Stork) light plane, Bachem was told Himmler would see him on a certain day in early 1944. Himmler had expanded the SS, which had begun merely as a bodyguard, to become a separate military service branch — thinking ahead to the day when he would replace Hitler and rule the Reich. Spurned by the Air Ministry and the Luftwaffe, Bachem had been led to believe that the SS chief would be receptive to becoming involved in military aviation.

Bachem was thinking that if Germany’s air force wouldn’t field his extraordinary aircraft, the SS would! No record survives of the Bachem-Himmler meeting. but afterward the Natter, which had been stalled, received a go-ahead, with Himmler becoming its champion. Shortly afterwards the RLM informed Bachem that it had reconsidered and was also affording high priority to development of the aircraft it now officially designated Ba 349.

With stubby little wings spanning less than a dozen feet, it was a very small target, and pushed through the sky by rocket power it was exceedingly fast. Bachem’s rocket-armed aircraft was in many ways more like an artillery shell than a fighter plane.

Fighting the Natter would have been difficult for P-51 Mustang pilots and near impossible for gunners aboard B-17 Flying Fortress and B-24 Liberator bombers. The Natter was designed to hit and run. With stubby little wings spanning less than a dozen feet, it was a very small target, and pushed through the sky by rocket power, it was exceedingly fast. Bachem’s rocket-armed aircraft was in many ways more like an artillery shell than a fighter plane.

 

Simple and Strategic

In September 1944 the Technical Office of the Waffen-SS issued an order for Bachem to build the Natter at his Waldsee factory.

The Natter had strengths, including the advantages of being cheap and simple. Bachem must have wondered why others were slow to grasp the beauty of it – a sky full of Natters, blasting B-17s right and left.

The concept was an accountant’s dream in a nation worried about a shortage of strategic materials. The Ba 349 was a crude airframe, intended for ease of manufacture by unskilled woodworkers.

Bachem Ba 349 Natter

U.S. Army soldiers inspect captured German Bachem Ba 349 Natters at the end of World War II. U.S. Army photo

The design of the wings was too simple for words: they were plain rectangular slabs of wood devoid of ailerons, flaps or control devices. The control surfaces to make the Ba 349 roll, pitch and yaw were installed on the four fins of its asymmetrical cruciform tail. The four control surfaces in the tail were also connected to guide vanes directing the rocket exhaust that augmented aerodynamic control.

The nearly cylindrical fuselage was wrapped around a Walter 109-509A-2 sustainer rocket capable of putting out thrust for 70 seconds at full power, and dependent upon volatile liquid fuel. The aircraft was to be aided in its vertical launch by what would later be called boosters — four Schmidding 109-533 solid-fuel rockets, two on each side, able to generate thrust for 10 seconds, necessary because fully loaded the aircraft weighed too much for the Walter rocket to lift on its own. As Allied bombers passed overhead, the Natter would be blasted vertically off the ground, climbing almost vertically on its internal rocket. Nearing the bombers, the pilot would sight on one and fire his battery of rocket projectiles. He would then use his remaining kinetic energy to climb higher than the bombers and swoop back for a ramming attack. Just before impact the pilot was to trigger a mechanism to separate his forward fuselage and let him bail out. The idea of a ramming attack was short-lived, abandoned with the early scheme of a separate forward fuselage section, but the remainder of the scenario remained unchanged: the Natter would go straight up, attack, and recover.

Lest there be any doubt of Himmler’s influence, the SS openly took charge of Natter development and of unpowered, manned flights in which the Natter flew as a glider.

The Natter had no landing gear, which saved weight, expense and construction time. The pilot and aircraft were meant to be recovered safely but separately. After intercepting bombers and discharging its weapons, the Ba 349 was to dive to a lower altitude and flatten out into level flight. The pilot would then open the cockpit canopy, be thrown clear, and open his parachute. A separate chute would bring the relatively lightweight Natter safely to the ground, ready to fight another day.

 

SS Scrutiny

Lest there be any doubt of Himmler’s influence, the SS openly took charge of Natter development and of unpowered, manned flights in which the Natter flew as a glider. In December 1944 the project came largely under the control of the SS and Gen. Dr. Ing. Hans Kammler, a longtime Himmler loyalist who’d razed the Warsaw Ghetto and who employed domestic prisoners to create an underground V-2 rocket assembly facility at the Mittelwerk, one of a complex of underground factories employing slave labor near Nordhausen in central Germany.

Bachem Ba 349 Natter

A U.S. Army soldier listens to a description of how the Bachem Ba 349 Natter worked from an unknown German. U.S. Army photo

The first of just 15 Natters that were completed became available in October 1944, and was used for four unpowered handling trials, towed aloft behind a Heinkel He 111 twin-engine bomber. Erich Klöckner piloted the Natter. Three times, it performed as predicted.

On the fourth flight, something went wrong. Klöckner abandoned the first Ba 349, known as aircraft M1, in mid-air and parachuted to safety.

To clear doubts about the Natter in the glider mode, Hans Zübert made a daring free flight in M8 on February 14, and showed that once it was aloft and level, the Natter was a stable and comfortable aerodynamic platform.

The problem was getting there.

Bachem comforted the pilot as they talked moments before the launch. If the Natter should veer off course, Bachem told Sieber, he should execute a half roll to stabilize the ship and attempt a recovery. Sieber’s Natter was equipped with an FM transmitter for the purpose of transmitting data from monitoring sensors in the machine, and Sieber also had an interphone that connected him to engineers in the launch bunker.

The first vertical launch with booster and sustainer rockets firing, but without a pilot in the cockpit, took place Feb. 23, 1945. Bachem was now under pressure from authorities in Berlin, who were telling him to achieve a manned vertical takeoff by the end of February.

 

March Mission

In fact, it was March 1, 1945 when test pilot Lothar Sieber briefly became the bravest man in the world.

The location was Heuberg near Stetten am kalten Markt, Würtemberg on an artificial plateau at a Truppenübungsplatz (military training area). Just short of his twenty-third birthday, seasoned pilot Sieber strapped into the fully fueled, camouflaged Natter vehicle No. M-23 for history’s first manned vertical takeoff of a rocket.

Bachem comforted the pilot as they talked moments before the launch. If the Natter should veer off course, Bachem told Sieber, he should execute a half roll to stabilize the ship and attempt a recovery. Sieber’s Natter was equipped with an FM transmitter for the purpose of transmitting data from monitoring sensors in the machine, and Sieber also had an interphone that connected him to engineers in the launch bunker.

Bachem Ba 349 Natter

A closer view of the German Bachem Ba 349 Natter experimental vertical take-off fighter-interceptor, captured by the U.S. Army in Austria 1945. U.S. Army photo

The launch began as planned. On cue, the Walter main rocket motor built up to full thrust. Sieber depressed the switch to ignite the four rocket boosters.

The sound was shattering. The Natter lifted aloft in a cloud of steam and rocket smoke. It climbed rapidly to 500 feet, where it abruptly pitched back into a near upside-down attitude. Now, instead of climbing at 90 degrees it was climbing at 30, but in an inverted curve. Onlookers thought they saw the four boosters detach and fall to earth as they were supposed to, but in fact one failed to break loose.

Sieber executed a roll maneuver but could not make the aircraft recover. Engineers on the ground saw the cockpit canopy fly loose at 1,500 feet, suggesting that Sieber considered the aircraft out of control and had begun the escape sequence.

To the frustration of observers, low hanging stratus clouds swallowed up the Natter. The Walter motor was heard to cut out. The Natter soared to about 5,000 feet and then came straight down. It blasted a 15-foot crater into the earth about five miles from the launch pad. Altogether, the Natter had been in the air for about 50 seconds.

Anxious onlookers searched the sky for Sieber to come descending out of the clouds beneath a parachute canopy. He did not. At the impact site, rescuers found a grisly assortment of body parts, including half of a left arm. Before the main motor cut out, Sieber may have unintentionally become the first human to fly faster than sound (763 miles per hour at sea level. While there are conflicting theories of what led to the pilot’s death, most agree that something went wrong with the canopy.

Because an experienced test pilot had lost his life, Himmler’s SS canceled the Natter project, and wrote finis to what can only be viewed, with hindsight, as a brilliant mistake.

By

Robert F. Dorr is an author, U.S. Air Force veteran, and retired American diplomat who...