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HORTEN FLYING WING PROJECTS OF THE 30S

Horten aircraft almost always consist of wings only, i.e. they are planes without fuselage or vertical steering and stabilising elements as opposed to Alexander Lippisch's tailless planes. However, it was the later who inspired the Horten Brothers Reimar (1915-1993) and Walter (1913-1998) to take up their flying wing model experiments at the beginning of the 1930s.

The two brothers started to build their first glider, which was large enough to carry a human being, in their parents' flat. The flying wing known as the H I had a wing span of 12.4 meters and was test flown by Walter Horten on the Bonn-Hangelar Airport in July 1933.

An invitation to an air day at Bonn-Hangelar in July 1934 was seen as the first success. As official registration for the H I the name "D-Hangwind" was chosen, which was the nickname of Alexander Lippisch. The A-level student Reimar Horten was unable to get a day off at school. This and other organisational difficulties meant that he was only able to attend the end of the competition on the Wasserkuppe. His brother Walter, who was then 20 years of age, towed Reimar's glider by plane to the "Kuppe". Despite the fact that he only took part for a very short time, Reimar received a construction award for his H I of 600 Reichsmarks. He was however not able to take the H I back to Bonn and had to destroy it.

The next flying wing was a glider equipped with an engine. The H II m, the "D-Habicht", was also constructed at home in Bonn in 1934/35. In May 1935 the aircraft took to the air in Hangelar with the aid of a winch, since it had not yet been fitted with an engine. The pilot had to lie in prone position. The H II m received a borrowed overhauled Hirth-HM-60-Engine, which drove the two-blade propeller.

In 1937 Walter Horten served with the Fighter Squadron Schlageter in Cologne. His Section Commander was the well-known glider pilot Squadron Leader Oskar Dinort. He arranged the construction of three motorised H II gliders in the hangars of the military airfield Lippstadt and Reimar's transfer to Cologne. Unlike the H II which had been built in Bonn, there was a seat for the pilot in this gilder. Construction was delayed because of the occupation of the Rhineland. This explains why only two H II were completed in 1937 and only one in 1938. Furthermore the H II Ls could not be fitted with engines. The two flying wings which had been constructed in 1937 took part in the Rhön Glider Competition in the same year. Two of these robust gliders, which were able to perform aerobatics, were at the Horten Brothers' disposal for test purposes until the end of the war.

The next Horten Glider was the H III, which was built in Cologne and was basically a larger version of the H II with an increased wingspan of 20.4 meters. Two models piloted by Werner Blech and Heinz Scheidhauer took part in the Rhön Gliding Competition in 1938. Unfortunately they were caught in a terrible thunderstorm on 6 August 1938. Blech's aircraft, which was considerably damaged by hailstones, crashed into the ground. The pilot was hanging dead at the end of his parachute. He had broken his neck. Scheidhauer, however, was able to save himself despite frostbite.

With the help of the Ministry of Education and cultural Affairs a new H III could be constructed for the Rhön Competition in 1939. A further ten were supplied to the various Luftwaffen Glider Squadrons. Four H III took part in the competition. Another variation was the H III c with slats which could be extended when more lift was needed. It was initially tested in its extended state and did not really improve performance.

An H IIIb, which was being constructed in Bonn-Hangelar, was converted into a motorised glider with twin blade propeller by fitting it with a Walter-Mikron engine. The maiden flight of the H IIId took place on 29 June 1942. A second motorised glider H III e, which had been constructed in Göttingen, received an improved air-cooled VW engine and a fodable propeller and took off for the first time on 25 January 1944. What happened to the two motorised H III is not known today.

During proving flights to test the prone position of the pilot, two H III b were converted into H III f in Göttingen in 1943. From 8 July test flights started in Klippeneck. This was where Herman Strebel flew the first of two two-seater gliders, (H III g), on 10 July 1944. In autumn 1944 all these planes gathered at the Hornberg.

Soldiers of the Luftwaffe in Königsberg constructed the first high performance glider H IV as early as in 1940/41. This took place under the instruction of Reimar Horten, who had designed it in 1938. Heinz Scheidhauer carried out the maiden flight in May 1941. He had to take a kneeling/lying position in the glider. In the meanwhile three further H IV were being completed in Göttingen.

Comparative flights with the gliders Condor III, Weihe and Reiher in Trebbin as well as the D 30 Cirrus at the end of May in Darmstadt underlined the quality of the Horten glider. The Cirrus proved to be the only glider to perform better during flight, the H IV was superior to all the others. However, the serial no. 26 was damaged considerably during a crash landing on the Kippeneck and was never repaired. On 30 June 1943 the serial no. 24 with Zübert at the helm, collided with some telephone wires in Göttingen. The aircraft was repaired, but its wingspan had to be reduced from 20.3 meters to only 18 meters - at least it was still operational.

In December 1944 an H IV b with laminar profile was built in Bad Hersfeld and test-flown by Heinz Scheidhauer in Göttingen. It was then transferred to Göppingen. The profile was a copy of the American fighter North American P-51 Mustang. However, it gave the aircraft unexpected flight properties, i.e. wing swings and a tendency to spin, which Horten Gliders had never experienced before. The pilot Herman Strebel died as a result on 18 January 1945, when he had to get out of the H IV. His parachute did not open, and he fell to his death. As a result the series production of the H IV b, which had already started, came to a sudden end.

The first twin-engined Horten flying wing was the H V a, built in 1936/37. This aircraft consisted mainly of the plastic "Trolitax" of the Dynamit Nobel AG. The Troisdorf firm supported the construction of the H V a to test its product. The two pilots were lying in a middle section, which was lined with glass clear cellon. The glider had novel swing-wing steering at its wing tips and two HM-60-R-Engines, which drove the twin blade propellers. The main undercarriage was rigid, the nose landing gear was retractable.

The first test flight took place in spring 1937 at the Bonn-Hangelar Airport. Since the two engines were fitted at the back of the aircraft, the glider's tail section proved to be too heavy. The aircraft only made a quick jump into the air and then a hard landing. Since the plastic was very porous, the H V a was destroyed entirely. Walter and Reimar Horten, the pilots, walked away with minor injuries.

With the help of Squadron Leader Oskar Dinort the H V b was being built for training purposes in the hangars at Cologne-Ostheim. It was made from conventional materials and without swing-wing steering. The two pilots were sitting upright and looked through two separate head bubbles. The fuselage was rigid and covered up to the nose wheel. The engines of the H V a were re-used. However, this time they were fitted towards the front and were connected via drive shafts to the propellers. In autumn 1937 Walter Horten carried out the H V b's maiden flight in Cologne-Ostheim. Further test flights were thwarted with the onset of World War II.

Since the beginning of the war the H V b was left in the open air in Potsdam-Werder and was in danger of slowly rotting away. Walter Horten approached all the relevant authorities in an attempt to save the aircraft. He was finally successful in September 1941. The "Special Command L In 3" lead initially by Commander Reimar, and then later by Walter Horten, was founded in 1941/42 for the construction of the H VII near Preschke, Minden. This Special Command took on the re-construction of the H V b under the new name H V c. The two-seater was changed to a single seat, the construction method and the engines stayed the same. The maiden flight took place on 26 May 1942. Afterwards Walter Horten took the flying wing to Göttingen, where it was made available to the Aerodynamic Test Institute (AVA). Prof. Joseph Stüper was in charge of Research and carried out some test flights with the H V c in the early summer of 1943. During the last take off he was unable to clear one of the hangars, slid across the roof and dropped off the back of the building. Prof. Stüper managed to escape with no more than a fright, but the aircraft was damaged considerably. The intention was to re-build it after the war. However, it later became the victim of clearance work undertaken by US Troops and was burnt.

From page 90 of FLUG REVUE 8/99