Österreich-Ungarische Hubschrauber

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Anscheinend hat Österreisch-Ungarn wärend des Ersten Weltkriegens an Hubschraubern gebastelt (musste alles hier reinkopieren, da die Ursprungsseiten Werbung enthalten):

Petroczy PKZ1 (1917)
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[FONT=Verdana, Arial][SIZE=-1][FONT=Verdana, Arial][SIZE=-1]Oberleutnant Dr. Theodor von Karman (later of Cal Tech fame) and Ingenieurleutnant Wilhelm Zurovec, both attached to Flars, were assigned the task of constructing a prototype helicopter applying the latest information from the propeller laboratory. Eschewing endless theoretical calculations, Karman and Zurovec proceeded with empirical trials. As first envisaged, the tethered helicopter had 10 to 12 lifting rotors arranged in a circle, but the problem of weight and complexity reduced the final choice to a four-rotor design. After testing rubber-band powered models without success, Zurovec conceived a unique compressed air motor (weighing 4kg and developing 6hp at 2400 rpm) which enabled him to construct a 35kg flying model. Starting in Junc 1917, flight tests explored various stabilizing surfaces, center of gravity shift, and rotor configurations. Unable to achieve dynamic stability with one or two tethering cables, Karman and Zurovec found that a three-cable system gave the best results. A further 50 flights, ranging in height from 10 to 15 meters, were performed in the great balloon hangar at Fischamend between July 1917 and March 1918.
Meanwhile, on 21 August 1917, the MAG company in Matyasfold had been given the task of building a full-scale, manned helicopter based on the Karman-Zurovec model work. Having little financial incentive and directed by the military bureaucracy, MAG progress was slow, to some degree due to late delivery of the Daimler electro-motor. Completion, scheduled for October, did not occur until February 1918. The aircraft, called a Schraubenfesselflieger (SFF - rotor-driven tethered aircraft) was identified in post-war literature as the Petroczy-Karman-Zurovec PKZ 1. The design was patented jointly by Karman and Zurovec (German patent 346,425, dated 28 June 1917). Karman remained as project director, but it appears that Zurovec began work on his own PKZ 2 helicopter project in November 1917. The PKZ 1 motor weighed 195kg and produced 190hp at 6000 rpm - 60hp less than projected because the winding insulation was of inferior quality. In flight, power would have been transferred by an aluminum cable 800 meters long. On the first test in Fischamend (date unknown), the PKZ 1 (empty weight 650kg) took off with surprising abruptness at a rotor speed of 700 rpm and rose to the maximum tethered height of 50cm. Next, three men climbed aboard and the helicopter easily hovered at the limit of the restraining cables. After 15 minutes into the fourth flight, the over-burdened motor burned through. With high-grade electrical copper and quality insulation impossible to obtain, Daimler was unable to repair the motor. Since the private initiative of Liptak had sped the PKZ 2 to completion, the PKZ 1 was transferred to the Liptak factory but, lacking a motor, nothing was done. Nevertheless, the PKZ 1 had demonstrated the feasibility of an electric-powered helicopter as predicted by the model tests in Fischamend.
[SIZE=-2]Peter Grosz "Austro-Hungarian Army Aircraft of World War I", 2002[/SIZE][/SIZE][/FONT][/SIZE][/FONT]
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[/SIZE][/SIZE][/FONT][/SIZE][/FONT][FONT=Verdana, Arial][SIZE=-1] Prior to the First World War, it seemed that no one quite knew what the helicopter was good for, much less how to solve the problems associated with it. A balloon could certainly accomplish the primary requirements for the helicopter: vertical take-off and landing, and hover. With the success of the airplane, it seemed to many that the rotary wing inventors were wasting their time with helicopters and had missed the news that powered flight had been achieved. Fixed wing aircraft quickly found military uses during World War I, however, first for reconnaissance, and then as bomber and fighter aircraft. The aircraft was also found to be quite adept at shooting down enemy reconnaissance balloons. The balloon, however, had a much needed capability that the airplane lacked: the ability to connect a telephone line to the ground to report the events from the battlefield.
During the war, Lieutenant Stefan von Petroczy of the Austrian Army Balloon Corps initiated a project to develop a tethered, armed aerial observation platform that could be quickly reeled in when needed. Under the technical guidance of the now legendary Theodore von Karman, with assistance from Ensign Wilhelm Zurovec, a 650kg full-size machine, referred to as the [B]PKZ 1[/B], was begun in Budapest in October 1917. A 190hp Austro-Daimler electric motor was used to drive two propellers in front of the observer and two behind. The electrical power was transmitted through a cable but still the motor weighed 195kW. Four test flights were made in March 1918 up to a height of 6m, but the motor burned out, preventing further tests.
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Petroczy-Karman-Zurovec PKZ 2 (1918)
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[FONT=Verdana, Arial][SIZE=-1][FONT=Verdana, Arial][SIZE=-1]The Petroczy-Karman-Zurovec PKZ 2 helicopter, despite its name, was invented by Wilhelm Zurovec for which he alone received German patent No. 347,578, dated 12 February 1918. Unlike the PKZ 1, which was government funded, the PKZ 2 was privately financed by the Hungarian Bank and the firm of Dr. Liptak & Co AG, a large iron foundry and steel fabricator located near Budapest which established an experimental section under Zurovec's direction in late 1917.
The PKZ 2 has been amply described in post-war and contemporary literature, yet in virtually all accounts the design is incorrectly attributed to Karman who, in 1919 by claiming sole authorship and totally neglecting to mention the true inventor, Wilhelm Zurovec, deviously reaped the lion's share of the honors (documented by Zurovec correspondence in the Karman Archive). It is a great pity that Zurovec has never received the full measure of recognition that he surely deserves as one of the outstanding pioneers of helicopter development.
In the design of the PKZ 2 helicopter, Zurovec incorporated the concept of using counter-rotating rotors to cancel torque effects. Each rotor, with a diameter of 6 meters, represented an ingenious combination of old-world craftsmanship with modern applied engineering. Power was supplied by three 100hp Gnome rotary engines, that drove the rotors at 600 rpm through a common gearbox. The light, tubular airframe, easily disassembled for transport, rested on a patented central air-bag cushion (1 meter diameter) and three smaller cushions mounted on the outriggers. The cushions were kept inflated by an air pump attached to the rotor drive. Three tethering cables affixed to the outriggers ran through pulleys anchored in the ground and were controlled by separate, electric winches. The total weight of the PKZ 2 with fuel for one hour, but without observer and machine gun, was approximately 1200kg. Two forms of parachute rescue were planned. One was to carry the observer and aircraft safely to earth, and the other was a cannon-launched parachute that would clear the rotors and lift the observer to safety.
The PKZ 2 was test flown for the first time at the Liptak factory on 2 April 1918. After several flights, one lasting up to one hour, tests were suspended on 5 April because engine power was insufficient to permit safe hovering above 1.2m height. The Gnome engines were replaced by three 120hp Le Rhones. Flight testing continued from 17 to 21 May, during which flights between 10 and 50 meters altitude were recorded. During periods of calm weather and smooth engine operation, the excess lift measured at ground level was 150 to 200kg. As the PKZ 2 climbed, the loss of ground effect and the increase in tethering cable weight steadily reduced the excess lift. Yet, as long as excess lift sufficed to maintain proper cable tension, the PKZ 2 remained in stable hovering flight. At higher altitudes, the excess lift became marginal, causing the machine to slowly oscillate with increasing amplitude. Provided the tethering cables were retracted at about 1.5m/s, the oscillations to cease in about 15 to 20 seconds.
On 10 June 1918, Zurovec was called upon to demonstrate the PKZ 2 for high ranking military authorities. Although the rotary engines had recently been overhauled, their operation the day before was erratic, and Zurovec, fearing the worst, was reluctant to proceed. But what could a mere Leutnant do against the weight of official brass eager to see the wonder machine fly? Taking advantage of the zero wind conditions, the PKZ 2 with the observer's basket in place took-off at 5:40 and twice rose to 7-8 meters height, showing "considerable rocking motion." The basket was removed and the PKZ 2 took off again at 6:07 in a wind of 6-7 meters per second, climbing to a height of 12 meters. Due to overheating, the engine power dropped off and the helicopter began to pitch with increasing frequency until the tether-winch crew could no longer control the machine. The PKZ 2 crashed from two meters height, severely damaging the airframe and splintering the rotors. In a careful review of progress to date, Uzelac, realizing that the technical problems were too complex to resolve quickly, cancelled the project on 21 June 1918. Zurovec, Karman, and Liptak were directed to compile a record that would be a basis for further investigation when peace returned. Zurovec, refusing to accept defeat, devised a method to water-cool the rotary engines! He reported on 1 September that the PKZ 2 helicopter would be ready for further testing or 1 November 1918. By then it was too late.
[SIZE=-2]Peter Grosz "Austro-Hungarian Army Aircraft of World War I", 2002[/SIZE][/SIZE][/FONT][/SIZE][/FONT]
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[FONT=Verdana, Arial][SIZE=-1][FONT=Verdana, Arial][SIZE=-1] Powered by three 90kW airplane engines, this captive observation helicopter was the creation of Stefan Petroczy, a lieutenant in the Austrian Army during World War I. At first the machine failed to perform, but young professor Theodore von Karman — who later emigrated and became a leading American aerodynamicist — joined the effort, and eventually the aircraft flew to a height of over 45m. Supported by two massive wooden propellers turning in opposite directions, the Petroczy-Von Karman marvel was intended to lift a pilot, observer, and fuel for an hour's flight. During flight the machine was anchored to the ground by outrigger cables. There is no record that it was developed beyond the experimental stage.
[SIZE=-2]C.Gablehouse "Helicopters and Autogiros", 1969[/SIZE][/SIZE][/FONT][/SIZE][/FONT]
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[FONT=Verdana, Arial][SIZE=-1][FONT=Verdana, Arial][SIZE=-1]The PKZ 1 was followed by the 1400kg PKZ 2, primarily developed by Zurovec. The triangular structure used three 100hp Gnome rotary engines powering two counter-rotating propellers. The engines were soon replaced with 120hp Le Rhone engines and flight tests resumed that May. The vehicle was flown over 30 times, eventually with a second observer, and reportedly achieved a tethered height of 50m and an endurance of 30 minutes. A crash during a military demonstration ended the project and the conclusion of the war terminated further study. The PKZ 1 and PKZ 2 demonstrated that the thrust to weight deficiency could be overcome and that useful vertical flight could be attained. Since they were tethered, however, they did not in any way attempt to address the controllability challenges. [/SIZE][/FONT][/SIZE][/FONT]
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Asboth Helicopter (1917)
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[FONT=Verdana, Arial][SIZE=-1]In late 1917, Oscar von Asboth left Fischamend to become a director of the Ungarische Luftschraubenfabrik GmbH, the former propeller manufacturing subsidiary of UFAG. At his own expense, Asboth commissioned UFAG to build a model helicopter followed by a man-carrying version based on the designs he had discussed with Balaban at Fischamend and for which he received Austrian patents 76,184 and 79,539 dated April 1917. His was a four-rotor helicopter tethered by a single cable attached to the airframe by a gimballed yoke that allowed the airframe to move about all axes. The four wooden rotors each had a diameter of 3 meters. Unfortunately, before any tests were run the model version, powered by a French 20hp rotary engine, and the virtually completed full-sized airframe were destroyed in a fire at the UFAG factory on 9 September 1918. Five months of effort had come to naught.
[SIZE=-2]Peter Grosz "Austro-Hungarian Army Aircraft of World War I", 2002[/SIZE][/SIZE][/FONT]
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Balaban-Bloudek Helicopter (1917)
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[FONT=Verdana, Arial][SIZE=-1]After leaving the propeller laboratory at Fischamend, Balaban became chief engineer at UFAG. Working with Oberingenieur Stanko Bloudek, Balaban proposed a free-flying helicopter to Flars. In return, Balaban received detailed specifications that he felt were unrealistic and well beyond what could be reasonably achieved. On 27 August 1917, Balaban and Bloudek proposed to Flars a helicopter design that appears simple and practical. If accepted, UFAG agreed to have the airframe ready for testing within four weeks after delivery of a 100hp rotary engine. But Flars declined to support the work, much to Balaban's regret. Flight experimentation, performed at UFAG with a model having a 1.5m rotor diameter, demonstrated, perhaps for the first time, that auto-rotation in event of engine failure was feasible.
[SIZE=-2]Peter Grosz "Austro-Hungarian Army Aircraft of World War I", 2002[/SIZE][/SIZE][/FONT]
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Zum PKZ 2 gibt es sogar Modellbausätze!
 
Sehr interessant. Unter den meist erwähnten Pionieren der Hubschraubertechnik erscheinen diese gar nicht, obwohl ihre Entwicklungen recht richtungsweisend waren, z.B. die beiden gegenläufigen Rotoren die später beim Kamov u.A. verwendet wurden.

Die kuriose Konstruktion mit dem Beobachterstand über dem Rotor ist übrigens in den 60.ern in den USA experimentell wieder aufgenommen worden. Ich muss suchen in welchen alten Buch ich ein Foto von einem ähnlichen Gerät gesehen habe.
 
Ich bin am überlegen ob dieser Threasd vielleicht in Technikgeschichte besser aufgehoben wäre?

Diesen moderen Hubschrauber mit Beobachterstand würd ich aber gern mal sehn :)
 
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