The Bachem Natter Ba349 Manned Rocket
The Bachem Natter was projected as a small lightweight expendable interceptor, capable of destroying any enemy bomber using the least possible weapon expenditure. To achieve this objective, this ambitious project employed a vertical rocket-assisted takeoff followed by separate descent and landing of pilot and aircraft by separate parachutes.
It was believed that pilots having little or no experience would need only rudimentary flight and gunnery instruction, rather than spending valuable training resources on the finer points of flight training. Erich Bachem reasoned that, a reasonable number of such interceptors and launch sites could be installed around key industrial targets, to make attacking Allied bombers pay a prohibitively high price.
I notice in the power plant section ..you don't mention the Schmedding rockets. I was curious so I did the math, the Schmedding rockets would be 'L' motors in the model rocket world, 4 of them would kick butt. They also had a version that used two schmedding's but they were twice as big or 'M's..
I read up on the one manned natter launch. there are conflicting reports of what happened. the flight only lasted 32 seconds and the schmedding's burn for 80 seconds so it hit the ground right at peak thrust. probably wasn't a whole lot left to analyze. One is that the cockpit separated prematurely, with all that thrust that's a possibility. You mention the thrust broke the pilots neck, the second scenario which seems the more likely. ..was when it launched under full thrust the canopy tore loose and took off the pilots seat headrest, along with any of the pilot that was next to the headrest and on the way back that took out the vertical stabilizer. In model rocket language we call that CATO (catastrophe at Take off) Sparky (9/28)
Natter it's self nearly finished although I will have to find a trick to do the boosters , another wrinkle I use is where the fuselage has tabs with another section attaching and there is no room to get my fingers into the joint. I bend the tabs gently inwards about 45degrees and put glue on the tabs. The section without tabs can then be slid onto the tabs and the panel lines-camo lined up it is then a simple matter to put your finger inside and press the tabs into contact with the tab-less section. ( I need to do things this way as I us a contact adhesive where ever possible , speedy this way) Paul Needham
In reality, only one experimental vertical takeoff interceptor
was available in 1944. This simple innovative project designated
Bachem Projekt 20, which was accepted by the Air Ministry and
received the official RLM designation Ba 349, was code-named Natter
(Viper). It was manufactured in small numbers prior to the end
of the war. A second design with vertical takeoff capability,
the He P 1077 (see p. 152), failed to materialize except for a
few gliders that may have been completed prior to the war's conclusion.
The Bachem Werke GmbH was founded on February 10, 1942, by Dipl.-Ing.
Erich Bachem, formerly the Technischer Direktor of the Fieseler
firm. The company manufactured spare parts for piston-engine fighters
and other aircraft equipment before the Natter project was created.
The BP 20 was projected as a small lightweight expendable interceptor,
capable of destroying any enemy bomber using the least possible
weapon expenditure. To achieve this objective, this ambitious project
employed a vertical rocket-assisted takeoff followed by separate
descent and landing of pilot and aircraft by separate parachutes.
It was believed that pilots having little or no experience would
need only rudimentary flight and gunnery instruction, rather than
spending valuable training resources on the finer points of flight
training.
Erich Bachem reasoned that, a reasonable number of such interceptors and launch sites could be installed around key industrial targets, to make attacking Allied bombers pay a prohibitively high price. Other attributes of Natter included savings in the amount of steel and aviation fuel and the ability to be quickly transported from small, camouflaged sites. The ability to recover the rocket motor for reuse was considered an important feature of this aircraft, which was essentially a manned missile.. There were even plans to launch the interceptor from ships if the need arose.
The BP 20 was of wood construction and was to be built without
the use of gluing presses. Most of the parts could be made in
small woodworking shops through Germany, without interfering with
the existing needs of the aircraft industry. According to Erich
Bachem, ) only 600 man-hours were required for the production
of one airframe, excluding the HWK 509 A-2 rocket motor, which
was a relatively simple to manufacture when compared to sophisticated
turbojet.
The fuel capacity was to consist of 119 US gallons (450 liters)
T-Stoff and 66 US gallons (250 liters) C-Stoff, carried in separate
tanks. The available fuel was sufficient for 80 seconds at full
power, developing a thrust of about 3,750 lb (1,700 kg). Takeoff
assistance was provided by four solid-fuel rockets SR 34 which
produced an additional thrust of 2,200 lb (1,000 kg) for twelve
seconds.
Natter's weapon systems were simple and potentially devastating. They comprised either a honeycomb 24 electrically fired 73 mm F6hn air-to-air rockets, or 32 R40 air-to-air missiles located behind a jettisonable cover in nose section. The alternative, the Rheinmetall SG 119 consisted of six clusters, each cluster containing seven MK108 barrels grouped together in a cylinder with the clusters arranged about the Viper's nose as in a revolver.
Bachem
submitted his Natter project to the OKL and simultaneously to
the SS-F6hrungshaptamt (SS Planning Office), in August 1944. One
month later, a contract for fifteen experimental BP 20 aircraft
was awarded, and a few weeks later, Natter was included in the
J5gerNotprogramm (Emergency Fighter Program). The first experimental
aircraft, the Ba 349 M1 and M2, were under construction in October
1944, at a time when the RLM believed the Natter could be successfully
employed against Allied heavy bombers, including the anticipated
American Boeing B-29.30 The first batch of fifty Ba 349s was ordered
for delivery between October 1944, and January 1945. A measure
of the importance attached to the program is in the substantial
order of 200 Vipers at the start of mass production. 
The installation of parachutes delayed flight testing of the first
target defense prototype, the Ba 349 M1, until November 1944.
The Ba 349 M2 was completed soon thereafter and the first takeoff
under air-tow of the third prototype, Ba 349 M3, was made at Neuburg
on the Danube on December 14, 1944. A second flight behind a He
111 by the DFS, followed eight days later. After successful completion
of ground tests near Bad Waldsee on December 18, 1944, the first
vertical launch from a ramp was scheduled. This event was marred
when the Viper caught fire as a result of a technical fault. The
next attempt was made four days later at Heuberg Hill near Stetten
am kalten Markt. The aircraft was towed to an altitude of 2,460
ft (750 m) and parachutes were deployed to carry the Viper and
its simulated pilot safely to ground. The second takeoff occurred
on December 29, 1944, without serious incident while simultaneously,
other Vipers were towed into the air for further testing.
French armor advanced into Waldsee on April 1945 and a great number of spare parts was captured- Only a few days before the French arrived, fifteen rocket engines destined for Vipers had been thrown into Lake Waldsee to prevent their capture. The secret was not well kept however and all were later recovered.
Plans for mass production of the Ba 349 A-1 were authorized on
March 1, 1945, but only a few Natters were actually completed.
These were followed by the improved Ba 349 B-1 (Entwurf 2) interceptors
whkb were to be produced at Waldsee, but few were actually completed.
On of the models were powered by a solid-fuel rocket to evaluate
takeoff characteristics. Practical tests carried out at Peenemunde,
where a first test conducted during February 1945, proved unsuccessful.
Willy A. Fiedler, a testing engineer working for the RLM, was
sent to the Heuberg Hills to oversee the program Erich Bachem
is quoted after the war as having said that about twenty Vipers
had been used for practical tests. Fifteen were of the A-series,
and four B-series aircraft. All were constructed at Waldsee. Still
others were assembled by the Wolf Hirth glider factory. Four additional
Ba 349s, possibly of the B-series, were captured at the end of
the war by Allied forces near St. Leonhard, Austria.
   Some views of the Bachem 349 Natter (Viper) cockpit (see Dave Caldwell's paper model!) |
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