Horten Flying Wings

Almost all of the photos, unless otherwise credited, are from the wonderful book, "Nurflügel", by Peter F. Selinger and Dr. Reimar Horten

If its fuselage, tail, and engine nacelles contribute nothing to an aircraft's lift, why not get rid of them?

Nothing New Under The Sun...

When the newest American super-bomber, the Northrop B-2, was revealed to the public at Palmdale, California on November 22, 1988, many aviation history enthusiasts must have noted that the configuration selected by the aircraft's designers, namely that of the "flying wing," had been resurrected from the dead, as it were. Although present day experience has shown that the all-wing configuration is the best one for avoiding detection by enemy radar (aided by the latest technology in materials, electronics and computers), the same configuration has been in practical use since about 1930. The first jet-powered all-wing aircraft flew in Germany on February 2, 1945, and at the time was also virtually undetectable by radar, partly on account of its mixed construction (wooden wings).

In the United States, John Knudsen Northrop had been working on all-wing aircraft since the end of the 1920s. His first aircraft of this configuration (although it did employ two small vertical tail fins on thin tail booms) was the "Flying Wing," which flew in 1929. Because of poor economic conditions during the 1930s, Northrop's twin-engined all-wing N1M did not appear until 1940, and the N9M until 1942.

Individual projects were undertaken in various countries, but in the Soviet Union there were numerous attempts, some of them very promising, to learn the secrets of the all-wing aircraft. The most successful Soviet designer was Boris Ivanovich Chernanovski, who developed a series of projects from 1921 to 1940.

In Germany, the Horten brothers, Reimar and Walter, had in mind a pure all-wing aircraft with no vertical control surfaces of any kind. Inspired by the Stork- and Delta-type tailless aircraft of Alexander Lippisch, they began their work at the end of the 1920s. Successful flight tests of their first tailless glider were carried out at Bonn-Hangelar airfield in July 1933. By 1934 they were working at Germany's "Gliding Mecca," the Wasserkuppe. The all-wing concept had achieved its first practical success.

Although development of the all-wing aircraft began at about the same time in Germany, the Soviet Union and America, there was no collaboration whatsoever between designers. In spite of this, design teams in these widely separated parts of the world were convinced that the all-wing aircraft was the best configuration and pursued the idea with much idealism. It is no wonder, therefore, that the concept has been revived in the present day.

Reimar and Walter Horten were two brothers who were born and raised in the Germany of the early 20th century. This was an exciting time for aviation, as almost everything was new, and there was plenty of room for new designs. Being blessed with parents who supported their efforts, to the extent of having the dining room become part of the construction site, Reimar was fascinated by the idea of airplanes which consisted solely of a wing, without the struts, wires, wheels, and various surfaces which dominated the airplanes of the day. The Horten borther were not at all the inventors of the flying wing design which was already used in kites and gliders as early as 1904, but they were absolutely single-minded about it and they never designed and other type of planes than flying wings, called "Nurflügel" in German, which means "wing only."

The treaty of Versailles forbad Germany to construct aircraft. So, German engineers constructed gliders, and thus the Horten brothers started with gliders, building test models as early as 1929 when they were still young boys. Walter Horten spent the first six months of the war as fighter pilot on the western front, flying a Me 109 in Fighter Squadron No. 26.

In the 1930's and 1940's in Germany, the Horten Brothers, Walter and Reimar, built a succession of flying wing designs which were quite advanced, and on the cutting edge for their day. Their "Ho" series is as follows:

Ho I - 1931

A flying-wing sailplane.

Ho II - 1934

Initially a glider, it fitted with a pusher propeller in 1935. Looked like Northrop's flying wings.

Ho III - 1938

A metal-frame glider, later fitted with a folding-blade (folded while gliding) propeller for powered flight.

Ho IV - 1941

A high-aspect-ratio glider (looking like a modern sailplane, but without a long tail or nose).

Ho V - 1937-42

First Horten plane designed to be powered, built partially from plastics, and powered by two counter-rotating pusher propellers.

Ho Parabola

 

Ho VI - 1944

Clearly intended as a high aspect ratio glider with ultra-high performance to succeed the Horten IV.

Ho VII - 1945

Considered the most flyable of the powered Ho series by the Horten Brothers, it was built as a flying-wing trainer. (Only one was built and tested, and 18 more were ordered, but the war ended before more than one additional Ho VII could be even partially completed.)

Ho VIII - 1945

A 158-food wingspan, 6-engine plane built as a transport. Never built. However, this design was "reborn" in the 1950's when Reimar Horten built a flying-wing plane for Argentina's Institute Aerotecnico, which flew on December 9, 1960 -- the project was shelved thereafter due to technical problems.

Ho IX - 1944

The first combat-intended Horten design, it was jet powered (Junkers Jumo 004B's), with metal frame and plywood exterior. First flew in January 1945, but never in combat.

Ho XI

An acrobatic glider of 8 meters span. It was built at Hersfeld and had no features of special interest.

Ho XII

A light side by side two seater with a 100 hp engine.

Ho XIII

A glider to test the swept-back wing concept for the Ho X, but the war ended before Ho X was constructed.

After the War:

Postwar, the western Allies dismissed their work, though the British toyed with a transport version of the Amerika Bomber. Walter stayed in Germany and eventually rejoined the Luftwaffe; he was able to develop a Ho 33 two-seater glider in 1951. A first version was scrapped, a second flew, but the commercial prospects for the aircraft were not good, as it was much too large and cumbersome for a two place ship. Plans to mass produce it were abandoned.

After World War II Germany was prohibited from developing aircraft. So in 1948, Reimar Horten emigrated to Argentina where he continued to design flying wings, including the two-seater PUL 10. It was not to be a success, as he narrates in his biography:

Working conditions in Argentina were even more difficult than in Germany during the war. Spruce and thin birch plywood were not available; inferior local materials had to be used. Glue was the largest problem. The General in charge of the Institute had ordered that the glue be prepared in the chemistry department. By the time it reached us, it had started to harden, and was mostly spoiled. Several aircraft were lost due to glue-failures.

The destiny of a new prototype was also peculiar: No sooner had it flown before the Public Relations Department had it sent off to some remote village, where it would be on display in a park until grass started growing from the wings. Afterwards it was ready for the salvage yard. Nine sailplanes were produced under these rather difficult circumstances.

I. Ae. 34

Ho 15a was a double-seated glider, and 15b a single seated glider.

Ho XVI - 1950

Nicknamed "Colibri", it was designed a small tailless sailplane for the Buenos Aires club "Condor" in 1950. The first one crashed on landing, and no further model was built.

I. Ae. 38 - 1950

A cargo glider to transport oranges to Buenos Aires. In 1960, ten years after its conception, the I Ae 38 finally flew.

Afterwards, the aircraft was simply scrapped, and my employment with the Institute terminated.

Reimar Horten died in 1994. Walter Horten was living in the city of Baden-Baden and died there on December 9, 1998.

In the end, all that came from their work was a dozen aircraft whose beauty still astonishes. This is especially true of the Ho 229 fighter-bomber, a batlike warplane that wouldn't look out of place at a 21st-century air show--or combat airfield.

Credits:

Photo Credits: Parts of the photos are from the book, "Nurflügel", by Peter F. Selinger and Dr. Reimar Horten.

References:

• "The Horten H X Series Ultra Light Flying Wing Sailplanes", by Albion H. Bowers, NASA Dryden Flight Research Center Edwards CA.
• "Die Geschichte der Horten-Flugzeuge 1933-1960", by Reimar Horten and Peter F. Seliger, H. Weishaupt Verlag, Graz, ISBN 3-900310-09-2.
• "The Horten Flying Wing in World War II, The History and Development of the HO 229", by H. P. Dabrowski, Gablenberger Bücherkiste Schifferbooks, ISBN 0-88740-357-3.
• "The Horten Brothers and Their All-Wing Aircraft", by David Myhra, ISBN: 0764304410.

Several Horten models can be seen at the Deutsches Technikalmuseum (DTM) in Berlin, Germany. Four models (Ho IIL, Ho IIIf, Ho IIIh, Ho VI-V2 ) are preserved at The National Air and Space Museum ("The Smithsonian") in the US. A Ho IV is at the Planes of Fame Museum in Chino, California. The single Horten 33 belongs to the Wasserkuppe Museum.