Letov VR-1003 "Káně" (What If...)
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Great detective work, Daniel! Who would expect such a story behind the book for kids... 😉
Thank you, Robert. Yes, it was hard work, but it was worth it. 😄 😄 😄
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Post-war experimental VTOL aircraft
The Weserflug P.1003 was a single-seat vertical take-off and landing (VTOL) aircraft designed by the German company Weserflug Zeikbau in 1938. With the support of the German Ministry of Aviation, which was interested in military tiltrotors, this aircraft was developed with Dr. Adolf Rohrbach as chief designer. The most characteristic feature of this aeroplane is that the wings were rotated 90 degrees from the centre of the wing upwards; the propellers are directly above it, the vertical take-off is therefore performed in the same way as in a helicopter, and after take-off the wings are gradually rotated to a horizontal position; this ensures forward propulsion. The main wing is of the high type, to provide clearance for the huge propellers of four metres in diameter. Power was provided by a 12-cylinder Daimler-Benz DB600 series engine located in the rear of the cockpit with the air intake at the bottom of the nose. The landing gear was completely retracted into the fuselage. The P.1003 was a highly innovative concept. In the summer of 1944, work on the prototype began in the Protectorate of Bohemia and Moravia, specifically at the Letov company. Work proceeded very slowly and so by the end of the war the machine was not yet completed. The very interesting design of this aircraft did not leave our post-war experts cold and they decided to try to complete the prototype and put it into operation. The first engine test was carried out on 28 March 1946 on the airfield of the Letov factory. During the test, strong vibrations of the propellers were noticed, and therefore the test was aborted. These vibrations were still present in subsequent tests and the technicians were unable to find their origin for a long time. Further tests and trials revealed problems in maintaining and tuning the complex power transfer mechanism, which operated the propellers at the ends of both wings by a single motor, and engine cooling was also a problem. After many innovative modifications, the sixth engine test on 11 September of the same year was already successful and the vibrations remained within tolerable limits. It was decided to continue with the project and get the aircraft into the air. This was accomplished in the summer of the following year, specifically on June 3, 1947, when VR-1003 successfully rose several meters above the test area and managed to stay aloft for nearly a quarter of an hour, after which the test was terminated. The enthusiasm of all involved was unbounded and it was decided to fine-tune the surface of the aircraft and to paint it so that the machine could be presented in full parade to representatives of both the civil and military sectors. The choice was made for a futuristic blue-silver colour, the propeller cones received a red colour, the propeller blades remained in the original black-green colour. A stylized Czechoslovak flag and the VR-1003/1 marking were painted on the rudder, the OK-1003 call sign was sprayed over the fuselage and on the right wing (in the direction of flight from above and below), and the nickname "Kane" was handwritten under the cockpit. After that the machine was shown on static demonstrations to selected officials, the dynamic test was to take place in November. Unfortunately, however, it did not take place, because at the end of 1947 Letov was beginning to feel a shortage of material and professional staff. The final grounding of VR-1003 was confirmed in February 1948, after which all costly projects were stopped and most of them scrapped. The subsequent fate of this unique machine is shrouded in mystery. It is not known how, or where, the machine itself, its photographs, its drawing, or oral or written testimony could have been seen - but the trace of the VR-1003 can still be seen today in another, completely unrelated area. This is the book „O letadélku Káněti" by the writer Bohumil Říha, which saw the light of day in 1957. Looking at the original illustrations by Rudolf Šváb, or the more recent pictures by Helena Zmatlíková, it is striking how similar the "Káně Airplane" is to the VR-1003, be it in colour, construction or flight characteristics. Coincidentally, neither is the name that the writer Říha gave it! It is worth noting that a machine of similar concept (but much higher parameters!) was successfully flown after a very long time by the Americans in 1989, and it was put into service after protracted tests only in 2007 under the name of V-22 "Osprey". The story of our Kane lives on at least in books...
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