History

Reimar Horten, an aerodynamic genius
We owe our success to Dr. Reimar Horten who is considered the father of the flying wing. He was with us from the beginning and we have named our company HORTEN Aircraft® in his honor. Before and during the Second World War Reimar Horten and his brother Walther were considered the top secret "men of hope" of the German Luftwaffe. For the first time we have built a viable company in order to market the flying wing.

Four different flying wing designs were in mass production by the end of the war. After the war ended the Allies prohibited further flying wing development in Germany. But the United States continued research of its own with Northrop`s flying wings. Years later NorthropGrumman built the well known B-2 bomber. 

Decades ahead of his time
Reimar Horten guided us in the design and the construction of the PUL 9 and the PUL 10. His dream was to make the flying wing available to the public. With this in mind he encouraged the Italian company NIKE Aeronautica to join us. Its owner, Dr. Giampiero Fabbri is part of our team. This is the story of Dr. Horten, an aerodynamic genius who was so far ahead of his time that for decades the world was not ready for his revolutionary designs. But as you will see it reads like a Hollywood story, one from which you may benefit from the happy ending. 

Walter Horten, his most important companion
Most of the ideas for tailless aircraft were Reimar Horten`s. His brother Walter was a gifted negotiator who secured support from the German Air Ministry. We wish to acknoledge Walter`s efforts which were instrumental in making possible the many years of research and developement of the Horten flying wings. Reimar Horten died at the age of 78 in Argentina in 1993. We believe that he knew that one day HORTEN Aircraft® would fulfill his dream and we are confident that his vision will be his eternal legacy.

 

The years Before World War II

Workshop in the dining room
The Horten Brothers, Reimar (born December 03, 1915) and Walther (born November 13, 1913) were the two sons of Professor Dr. Max Horten who was an instructor of Oriental Culture at the University of Bonn. The early 20th century was an exciting time for aviation, as almost everything was new. The aviation world was open to new ideas on how to build a flying machine.

At the age of 14, Reimar Horten was convinced that the most efficent aircraft would be all wing and this set the course for his life`s work. The brothers were blessed with parents who always supported their efforts. Their activities began in Bonn, Germany about 1930 and were carried out in their Venusbergweg family home.

Prize: 600 Reichsmark at the Rhön glider contest
Their first man carrying flying wing was named the H I. In1934 it received a prize of 600 Reichsmark at the Rhön glider contest. The next glider, the H II was completed in 1935. The flight tests proved that the bell shaped lift distribution was the key to safe flight. A demonstration flight of a motorized version in 1936 attracted the attention of the "Reichsluftfahrtministerium". Even though during this flight the propeller shaft broke and the propeller fell off, Walther Horten made a safe landing right in front of the hanger. Impressed by this, Major Dinort gave the order to build three powered H II`s in the hangars of the Fliegerhorst in Lippstadt.

Hanna Reitsch tests the H II
Germany`s legendary test pilot Hanna Reitsch stated after flying the H II on November 12, 1938; „There was no possible control movement which could bring the H II into a spin or even cause it to tip over on one wing. With the stick pulled all the way back and to the right the airplane rotates slightly in front and descends but accelerates to no faster speed than 90 km/h. This is very useful during flying in the cluods when the instruments are frozen." 

The "New York Times" reports
Before the war the H II was demonstarted at many air shows in which it was put into nose dives of up to 450 km/hr. In 1938 the New York Times published an article with a full page picture of the H II and the headline "Flying wing over Berlin". Shortly thereafter the US company Northrop was awarded a contract to develop flying wings.

The first plastic (composite) airplane
In 1935 Dynamit Nobel AG in Troisdorf sponsored the construction of the H Va. It was the first plastic (composite) aircraft in the world. It resulted in a number of patents which later led to the first parts being made using sandwich construction. In 1937 the construction of a new H IVb was ordered with conventional materials. This plane was the first flying wing to solve the "Mitteneffekt" problem (the "Mitteneffekt" describes a loss of lift along the longitudenal axis through the center of the airframe.) In 1938 the H III with a 20 m wingspan was constructed as a high performance glider for the Rhön contest.

Luftwaffe finances 10 gliders
In spite of a tragic crash of an H II after flying into a thunderstorm during a Rhön contest people were impressed by the performance of the flying wing. The University of Berlin gave them use of a workshop to continue flying wing developement.

They were given all the funds they needed to build ten H IIIb`s. In 1939, Heiz Scheidhauer, one of their test pilots, earned the Golden Performance Glider Award for soaring 340 kilometers.

 

The War Years (1939-1945)

Soaring with 400 kg ammunition
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. Reimar Horten was also trained as an Me 109 pilot, but later in August 1940, transferred to the glider pilot school in Braunschweig.There, Five Ho III b's and two Ho II's were modified to carry ammunition during Operation Sea Lion, the planned invasion of England.

Flight tests showed that when the H IIIb was loaded with 400 kg of munition, which gave it a gross weight of 750 kg, it not only retained its stable flying characteristics, it would even soar in thermals.

High performance Sailplane with 20 m wingspan
When operation Sea Lion was cancelled, the construction of the high performance H IV sailplane began. This glider featured an unusual but comfortable kneeling position for the pilot. In August 1941 the H IV was measured with a glide ratio of 32 to 1, very impressive in those days. (Later after the war in July 1952 Rudolf Opitz entered an H IV in an American gliding contest, where he won first place.) Walter Horten was eventually assigned to the headquaters of the "Luftfahrtministerium" where he was put in charge of single engine airplanes. In 1941 the Special Command "L In 3" was established in Minden/Westfalen under the command of Reimar Horten. There he was ordered to built six additional H III`s.

Foundation of the special command "L In 3"
The third „Luftwaffen" Inspection ordered an H VII flying wing as a trainer for fighter pilots. The Special Command „L In 3" employed thirty additional aeronautal specialists and moved to Göttingen. At the same time Reimar Horten continued his studies of aerodynamics and later earned his doctorate under the famous Prof. Prandl. In February 1943, Prof. Prantl saw a presentation of the H III d in Göttingen and called the Horten flying wings „ a significant part of the entire aircraft developement". 

Horten wins bid "3x1000"
Reichsmarschall Göring wanted the developement of an aircraft with 1,000 km/hr airspeed, 1,000 km range and the ability to carry a bomb load of 1,000 kg. This was the H IX project.

The importance of flying wings was proven by the fact that famous factories like Messerschmitt, BMW, Heinkel und Focke-Wulff incorporated the Horten ideas into their own flying wing designs.  

Göring commands maiden flight within 6 months
In 1943 Walter Horten was transfered to Göttingen to work with his brother. He took over the command of "L In 3" which was renamed Luftwaffenkommando IX. After a presentation in 1943, Göring gave the order to make unpowered test flighs of the H IX within 6 months.

Project operates under top secrecy
The group was divided into several teams that could operate independently in case some of them were discovered by the Allies. The high speed flight project was transfered to Bad Hersfeld where one H VIII was built just before the war ended. The test flight group was transfered to the Wasserkuppe (Rhön). The developement and construction of the H VI was transfered to the Eudenbach Aegidienberg Airport near Bonn, where two planes were finished. One of them was confiscated by the United States and thourougly meassured by the Northrop company but never flown. The Special Comand IX remained top secret and independent from the Luftwaffe, under Göring until the end of the war.  

Mass production of the H IX starts
The so called H IX V-1 had its maiden flight as scheduled on March 1st 1944 as an unpowered glider with impressive flight results. The H IX V-2 was finished 9 months later with two Jumo-004B-turbines. The test flights proved the concept. In the early summer of 1944 the Gothaer Waggonfabrik received the order for 40 H IX`s (sometimes named the Ho 229).

Fighter impresses during flight demonstration
The twin engine fighter H VII, with the center section built by the Peschke company, made its maiden flight in May 1944. Later a flight demonstration of the plane impressed the German aviation authorities, including Göring. It demonstrated extraordinarly stable and forgiving flight characteristics of swept back wings. The H VII V-1 also maintained good control after the failure of one of its engines in flight.

 In November 1944 flight tests of a glider called the H XIII with the wings swept back 60 degrees began in in Bad Hersfeld. These tests provided data for a proposed super sonic delta wing aircraft.   

Horten wins design competition for long range bomber
In the Autumn of 1944 the German aircraft industry was ordered to design a long range bomber which could carry a 4,000 kg bomb load 13,000 kilometers. Horten won the design competition, beating Junkers and Messerschmitt with a six engine long distance bomber, the H XVIII. Horten`s concept promised a 60 percent greater range than the designs of his competitors. The time schedule was daring: The first plane with a 40 m wingspan was to be built in 6 months with support from the Junkers company only.

Situation at end of World War
When the Allies came in April of 1945 the drawings were already completed and the construction nearly half finished. At the same time, assembly line production of 50 H IIIe`s was alredy in progress in the Klemm company. At the Gut Tierstein company in Rottweil the production of 10 H IVb`s was also in full swing. At the Peschke company the production of 20 H VII`s had just commenced and at the Gothaer Waggon company the first 3 of 40 H IX`s were completed.

There was a total of 120 different flying wings about to be built. The mass production was running just as the Allies invaded and terminated all airplane construction. Dr. Reimar Horten had built a total of 44 different airplanes, most of which were successfully flown. 

 

After The War

Destruction of the flying wings
Just prior to the Allied invasion the destruction of all flying wings and related plans was ordered. Most of the airplanes which were not destroyed were confiscated by the United States. The Horten brothers ignored the order and tried to hide all available plans in their parents house in Bonn. In March 1946 a special group from the Allies discovered and confiscated the documents.

Horten supports english company
Later, the Horten brothers were obliged to assist the Royal Air Force in Göttingen for a short time, to support developement of civil airliners. Reimar Horten applied for the mathematics exam in March of 1946 and earned his doctorate at the University of Bonn. He wanted to wait for more favorable times befoe continuing with flying wing development. These hopes were lost in 1947 when a rule extended the prohibition for Germans to participate in any aircraft industry related business. He attempted unsuccessfully to secure employment with the British company FAIREY which was developing a supersonic delta plane. While the comany management appreciated his efforts, the hostile atmosphere of the personnel towards Germans prevented effective cooperation.

Horten continues work in Argentinia
In April 1948 Reimar Horten emigrated to Cordoba (Argentina), where he was allowed to continue his work on flying wings. Walter Horten remained in Germany where he joined the new "Luftwaffe".

Reimar Horten`s first project in Argentina was the I. Ae. 34 (H XV a), a two seat glider designed for the Aeronautical Institute.

Bad conditions for aircraft production
During the construction of the first two planes he encountered many problems. Sometimes there was a lack of the basic materials such as plywood and glue. The substandard quality of the glue led to the loss of several wooden airplanes over the years. Most of the problems were in material procurement. Another factor was the insufficient skills of the employees as described in Horten`s words: "when an area doesn`t bond together properly (because of insufficient glue) it was hard to convince people that a thick nail does not replace a glue joint". Horten was forced to adjust his developements according to the material situation which was a considerable restraint for him. 

But that was not all. There was the bureaucratic structure of the Argentinian government and the internal organisation of the "Institutes Aerotecnico" to which he belonged. In his own words: "The prototypes suffered a special fate: once a plane flew, the public relations office,'Relaciones Publicas' sent it somewhere to a village in the country. There the planes, which were initially consructed for flight, were displayed outside until grass grew from the wings. Then they were ripe for the salvage departement which also belonged to the institute. Often only the second or third plane served its intended purpose."

Flying wing glider first cross the Andes
In 1950 Reimar Horten became director and member of the board of the newly established Soaring Institute in La Cruz, appointed by Brigadier General C. Ojeda. During that time several flying wing gliders were built and tested. In 1952 the first of four two seat gliders, the I. Ae. 41 (H XVc) was built. In October 1956 the German test pilot Heinz Scheidhauer was the first to cross the Andes with this glider and to land in Chile. The advanced hang glider the HXa "Alita", to be foot launched, was built and successfully tested during the first years of his term in office.

Development of Jet delta
In 1953, the single seat jet delta, the I. Ae. 37 was built and successfully tested as a glider. Tests in a super sonic wind tunnel with the two seat version, the I. Ae. 48 showed that a maximum speed of mach 2.2 and a minimum speed of 155 km/hr could be reached. In 1959, when the production of the first two planes had just started, the project was suddently canceled by the governement because of funding problems. 

Demand for transportation aircraft
However, Reimar Hortens`s main assignment was to solve a transportation problem in Argentina. Oranges rotted by the ton in the provinces while Buenes Aires turned to orange imports. Because there were no adequate roads, transportation by truck was impossible. Also fish could not be transported from Mar del Plata to Bahia Blanca. 

As a possible solution, Horten designed the I. Ae. 38 transportation aircraft with a 32 m wingspan. It was to fulfill the following requirements:

  1. Useful load, minimum 10 tons
  2. Minimum range, 1,000 km
  3. Operation out of unpaved air strips
  4. Loading and unloading from the rear

Unsteady political situation
Next a new minister took control and reduced the funding. Consequently the development of this all metal plane slowed down and it took 8 years to build it. More political compromises were demanded. Underpowered engines had to be purchased from an Argentinien company in an effort to boost national prestige. The airplane had only 43% of the power for which the aircraft was designed. 

In 1960 the plane was demonstrated to President Frondizi. He was especially impressed by its slow flight characteristics. But the project was canceled because of a modification of the national transportation plan and additional funding cuts. The plane was finally destroyed. 

Horten teaches aeronautical engineering
Reimar Horten then resigned from the Institute and started a new career as a professor of aeronautical engineering in the College of Cordoba. There he worked until his retirement in 1979.

     

More information on flying wings can be found in the following books:

  1. Nurflügel, die Geschichte der Horten-Flugzeuge 1933-1960 from Reimar Horten und Peter F. Selinger
    H.Weishaupt Verlag (Graz), ISBN 3-900310-09-2 
  2. Flying wings, Die historische Entwicklung der Nurflügel-Flugzeuge der Welt from Rudolf Storck
    Bernard & Graefe Verlag (Bonn), ISBN 3-7637-6242-6
  3. The Horten brothers and their all wing aircraft from David Myhra
    Schiffer-Verlag. ISBN 0-7643-0441-0