Bachem Ba 349

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Ba 349 Natter

Bachem Ba349 at the Deutsches Museum in Munich
Type	rocket interceptor
Manufacturer	Bachem
Designed by	Erich Bachem
Maiden flight	March 1 1945
Introduced	never
Number built	11 production aircraft (Ba 349B)

Bachem Ba 349 Natter (Adder) was a World War II era German experimental rocket-powered interceptor aircraft which was to be used in a very similar way as surface-to-air missiles. The pilot's primary mission was to aim the aircraft at its target bomber and fire its armament of rockets, with the majority of the flight to the bombers being radio controlled from the ground, and landing under a parachute.

1 Development
2 Natter launchpads at Kirchheim (Teck)
3 Survivors
4 Specification
5 External links
6 Related content

[edit] Development

With the Luftwaffe air superiority being challenged by the Allies even over the Reich in 1943, radical innovations were required to overcome the crisis. Surface-to-air missiles appeared to be a very promising approach to counter the Allied bombing offensive and various projects were started, but invariably problems with the guidance systems prevented these from seeing widespread use. Providing the missile with a pilot who could control the weapon during the critical terminal offered a solution and was requested by the Luftwaffe in early 1944.

A number of simple designs were proposed, most using a prone pilot to reduce frontal area. The front runner for the design was initially the Heinkel P.1077 that took off from a rail and landed on a skid like the Messerschmitt Me 163 Komet.

Erich Bachem's BP20 was a development from a design he worked on at Fieseler, but considerably more radical than the other offerings. It was built using glued and screwed wooden parts with an armored cockpit, powered by a Walter HWK 509A-2 rocket, similar to the one in the Me 163. Four jettisonable Schmidding rocket boosters were used for launch, providing a combined thrust of 4,800 kgf (47 kN or 10,600 lbf) for 10 seconds before they were jettisoned. The plane rode up a rail for about 25 metres, by which time it was going fast enough for the aerodynamic flight controls to keep it flying straight.

The plane took off and was guided almost to the bomber's altitude using radio control from the ground, with the pilot taking control right at the end to point the nose in the right direction, jettison the plastic nosecone and pull the trigger. This fired a salvo of rockets (either 33 R4Ms or 24 Hs 217s), at which point the plane flew up and over the bombers. After running out of fuel the plane would then be used to ram the tail of a bomber, with the pilot ejecting just before impact to parachute to the ground.

Despite its apparent complexity, the design had one decisive advantage over the competitors — it eliminated the necessity to land an extremely fast rocket aircraft at an airbase that, as the history of the Me 163 demonstrated, was extremely vulnerable against air raids.

After Bachem's design caught the eye of Heinrich Himmler at the SS, it emerged as the winner of the design contest. The Luftwaffe nevertheless managed to include some minor redesigns to try to save as much of the plane as possible, as well as eliminating the ramming attack.

A Bachem Ba349 displays its rocket armament

The resulting tiny plane was fired up a 50 foot (15 meter) wooden pole with the help of four solid fuel rockets, at the end of which it was already going fast enough for its control surfaces to work. The boosters burned out after 12 seconds, at which point the main engine was long up to full thrust. The mission now had the plane guided to a point in front and above the bombers, where the pilot would turn off the autopilot, and push over for a gliding attack. After firing its armament of rockets it continued gliding down at high speed to about 3,000 m (10,000 ft), at which point the plane "broke" when a large parachute opened at the rear of the plane, popping off the nose section and the pilot with it. Both would land under their separate parachutes, and only the fuselage with the wooden wings were disposable.

Wind-tunnel models which were built early in the program were shipped off for testing and the only results returned to the Bachem designers were that it would be "satisfactory" up to speeds of about 685 mph. Full sized models were then completed and started flight testing in November 1944. The initial versions didn't include an engine, and were towed in the air by a Heinkel He 111 bomber for glide testing. Other test articles were equipped with extra solid motors for launch and autopilot tests. All of these went well, but during testing it was shown that any attempt to re-use the engine was hopeless; the landing speed was simply too high.

Construction of the production Ba 349A models had already started in October, and fifteen were launched over the next few months. Each launch resulted in some small modification to the design, and eventually these were collected into the definitive production version, the Ba 349B which started testing in January.

In February 1945 the SS funders decided that the program was not going fast enough, and demanded a manned launch later that month. The first and only time that the aircraft was tested in this way was on March 1, when Lothar Sieber flew a Ba 349A, which was launched from the military training area near Stetten am kalten Markt. Things went well at first, but at 500 m (1,600 ft) the cockpit canopy pulled off. The plane suddenly turned over and flew directly into the ground. Siebert was killed in the accident, and the cause was never explained. It was suspected that the canopy may simply have not been properly latched before launch.

US forces overran the factory at Waldsee in April, but small numbers of Bachem staff had moved and taken the remaining ten B models with them. Soon the US had caught up with them again, and six of the ten were burnt.

Remnants of a Natter launch pad near Kirchheim

Several sources claim that an operational unit of Natters was set up by volunteers in Kirchheim unter Teck but didn't carry out any operations, but the evidence for this is inconclusive.

Coincidentally, in Japan during the last days of the Pacific War, the Mizuno aircraft company under orders from the Imperial Japanese Navy developed an aircraft similar to the Natter. The Mizuno Shinryu suicide-interceptor rocket aircraft was the result. It would have been armed with air-to-air unguided rockets mounted under its wings and used, like the Natter, for interception of enemy aircraft, as well as a nose mounted warhead to be used for a suicide attack.

[edit] Natter launchpads at Kirchheim (Teck)

There are three launch pads for the Bachem Ba 349 in the Hasenholz forest near Kirchheim/Teck at 48°37'42,2" N, 9°29'57,4"E, 48°37'42" N, 9°29'53,5"E and 48°37'39,8" N, 9°29'54"E. They are all that remain from the active launch site constructed in 1945. The three launchpads are arranged in the form of an equilateral triangle, whose sides point toward the east and the south. The distance between the launchpads is approximately 50 meters. The circular concrete pads on which the Bachem Ba 349's and their launch towers once stood still exist. In the center of each of the three concrete plates 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. The Natter launchpads at Kirchheim (Teck) might be the only remnants of these rocket launch pads still on publicly accessible terrain. The former test site for the Natter in Baden-Württemberg on the Heuberg near Stetten am kalten Markt is in an active military area, and therefore not accessible to tourists.

[edit] Survivors

A Bachem Ba349 at the Smithsonian Institute's Paul E. Garber Preservation, Restoration, and Storage Facility in Suitland, MD

Three Ba 349As survive today.

A restored Ba 349A is on display at the Smithsonian Institution's Steven F. Udvar-Hazy Center near Washington, D.C. This aircraft was captured at the war's end and transferred to Freeman Field, Indiana for evaluation. It was given the foreign captured equipment number T2-1. The U.S. Air Force transferred the aircraft to the The National Air Museum (now the National Air & Space Museum) on May 1, 1949. The aircraft was stored for many years at the museum's Paul E. Garber Preservation, Restoration, and Storage Facility in Suitland, Maryland before undergoing a full restoration. It was one of the first aircraft moved to the new center in 2004.

An additional unrestored Ba 349A remains at the Garber facility and restoration plans are unknown.

A restored Ba 349A is on display at the Deutsches Museum in Munich, Germany. This aircraft is painted to represent one of the unmanned test aircraft.

[edit] Specification

General characteristics

Crew: 1
Length: 6.02 m (19 ft 9 in)
Wingspan: 3.60 m (11 ft 10 in)
Height: ()
Empty weight: 800 kg (1,940 lb)
Loaded weight: 2,232 kg (4,920 lb)
Powerplant:
- 1× Walter HWK 509A liquid-fuel rocket, 16.7 kN (10,600 lbf)
- 4× Schmidding solid fuel rocket boosters, () each