A spare-parts shop in Waldsee

Erich Bachem had spent the 1930s at Fieseler in Kassel, rising to technical director, and had written books on gliding. In February 1942 he left to found the Bachem-Werke in Waldsee, a small town in Württemberg, as a supplier of spare parts to the aircraft industry. It might have stayed that way. In August 1944, after watching an American bombing raid on a German city, Bachem sketched an answer to the bomber streams: a manned, vertically launched rocket interceptor that needed no airfield at all.

A manned missile made of wood

The BP-20, soon called the Natter, or adder, was built almost entirely of glued and nailed wood so that unskilled workers could make it. It had no landing gear. Four solid boosters and a Walter liquid-fuel rocket would push it up a 20 m steel tower and to 12 km in about a minute, an autopilot would steer it towards the bombers, and the pilot would only aim and fire a nose full of unguided rockets. Then he would release the nose, and he and the rear fuselage would come down by separate parachutes. Bachem insisted it was not a suicide weapon.

Himmler says yes

The Air Ministry’s technical office thought the idea unorthodox. Adolf Galland backed it, but the decisive support came from Heinrich Himmler. Within 24 hours the project had top priority, and in mid-September 1944 the Waffen-SS ordered Bachem to build it at Waldsee; in December it came largely under the control of SS general Hans Kammler. The first prototype was finished on 4 October 1944, manned towed glider flights began at Neuburg on 3 November, and the first unmanned vertical launch from the tower on the Heuberg training area succeeded in December.

One minute on 1 March 1945

On 1 March 1945 a young volunteer, Lothar Sieber, climbed into the fully fuelled M23. It rose vertically, pitched over at about 100 to 150 m, lost its canopy at about 500 m and vanished into cloud, then dived into the ground some kilometres away. Sieber was killed, probably knocked out when his headrest, fixed to the canopy, was torn away. It was nonetheless the first vertical take-off under pure rocket power by a human being. All later Natter launches were unmanned. Pilots waited to fly from launch pads near Kirchheim unter Teck in April, but American tanks arrived first.

From rocket fighters to caravans

French troops took Waldsee by 25 April 1945, and the company’s war ended with Natters burnt or captured in the Austrian Alps. By Bachem’s own count 36 were built; German Wikipedia gives 30. One survives, unrestored, in the Smithsonian’s Garber facility. Bachem himself left for Argentina in 1947 or 1948, came back to build mine locomotives in Mülheim and, from 1957, designed lightweight caravans with Erwin Hymer. The Eriba name, still sold today, is taken from his own name or his wife’s.

Fabrieken

• Bachem-Werk · Waldsee, Württemberg — Built in spring 1942; Natter production and booster tests
• Heuberg test site · Ochsenkopf, Truppenübungsplatz Heuberg, near Stetten am kalten Markt — Vertical launch tower about 50 km from the works

Mensen

• Erich Bachem · founder and designer — Former Fieseler technical director; later co-designer of Eriba caravans
• Lothar Sieber · test pilot — Killed on the only manned vertical launch, 1 March 1945, aged 22
• Erich Klöckner · test pilot — Flew the towed glider trials from November 1944
• Hans Zübert · test pilot — Made the only free glide flight, in the M8, 14 February 1945

Records en primeurs

• First vertical take-off from the ground under pure rocket power by a person, Lothar Sieber, 1 March 1945
• First aircraft to use tailerons alongside a conventional rudder, according to German Wikipedia