Extensive preliminary tests and research were necessary before construction could be started. Because of the great speed and the extraordinary heat stress, special heat-resisting materials had to be found. The development, which cost millions, was almost completed at the end of the war. The then existing models were destroyed but the plant in Breslau where Miethe worked fell into the hands of the Russians who took all the material and the experts to Siberia, where work on these "flying saucers" is being successfully continued.
A German newspaper (not further identified) recently published an interview with George Klein, famous German engineer and aircraft expert, describing the experimental construction of 'flying saucers' carried out by him from 1941 to 1945. Klein stated that he was present when, in 1945, the first piloted 'flying saucer' took off and reached a speed of 1,3000 miles per hour within 3 minutes. The experiments resulted in three designs: one designed by Miethe was a disc-shaped aircraft, 135 feet in diameter, which did not rotate; another designed by Habermohl and Schriever, consisted of a large rotating ring, in the centre of which was a round, stationary cabin for the crew. When the Soviets occupied Prague, the Germans destroyed every trace of the 'flying saucer' project and nothing more was heard of Habermohl and his assistants. 
The German newspaper appears to have been Welt am Sonntag for (different dates are given) April 25 or 26 1953. The article is titled "Erste 'Flugscheibe' flog 1945 in Prag", and there is a photo of 'George Klein' pointing at the same vague diagram that Lusar reprints.
The Lusar question - solved
Very few writers have made clear that Lusar actually wrote his explanation of German disc developments in the context of worldwide flying saucer reports. Indeed, little emphasis has been placed on the fact that all of the material published prior to Lusar's book only appeared in that context, providing a relatively local angle on reports of flying saucers further afield. Given the total absence of tangible, objective, contemporary evidence to support any of Lusar's assertions, I think we can safely say that Nazi UFOs did not lead to any of the reports of flying saucers from 1947 onwards. It would be far more accurate to say that the flying saucer craze led to the making of increasingly false and hollow claims about the existence, and achievements, of Nazi UFOs.
I've been lucky enough to find, through the local library, a copy of the other key work - taking into account the assorted contributions of 'Renato Vesco' - in the 'Nazi UFO' mythos. This is the almost legendary German Secret Weapons of the Second World War by Rudolf Lusar, translated by R P Heller and M Schindler. The copy I have was published in 1959 by the Philosophical Library, New York, but printed in Great Britain. Lusar gives a little information about himself at the end of his Foreword, originally written for the German edition in April 1957. He says it was written in Munich, and he signs himself as "RUDOLF LUSAR (Major of the Reserve) (ret.)
I am not aware that any competent check has been made of Lusar's background, rank, or of how he obtained - as a mere retired Major - the vast amount of supposedly highly secret material he presents in this book. Some of which seems to originate only with Lusar himself.
Famed US researcher Martin Kottmeyer has been good enough to provide me with some 'Nazi UFO' material from a range of sources. One news cutting from the New Britain Herald for Thursday, March 14, 1957 is credited to AP, and is headed
No Flying Saucer Built by Hitler
Washington (AP) James H Doolittle says it "just ain't so" that Nazi Germany developed a flying saucer and a bomber that could attack the United States and return without refuelling. The veteran airman, chairman of the National Advisory Committee for Aeronautics, gave a House Appropriations subcommittee his estimate of reports published in Germany of great aviation accomplishments under Hitler. These were contained in a book by Rudolf Lusar, former German War Ministry special weapons chief.
I don't know much about weapons or aircraft, but I do know that this clumsy disc apparatus, with something like a large domed summerhouse on top, did not fly at more than 1100 mph, or climb to around 8 miles up in three minutes. How many aircraft ever have? I also know little about cameras, but enough to identify another of Lusar's claims as pure fabrication:
Let's just consider these cameras. For 24 cameras, between them, to "take 5,000,000 pictures per second" means that each camera would have to take, er, 208,333 pictures per second. Quite a shutter speed. And an ability to move 5,787 x 36-exposure films past that shutter in just one second. I suppose Cranz-Schardin might just have linked up 24 cameras to shoot in sequence at intervals of one five-millionth of a second, over 24 five-millionths of a second and no longer. But I very much doubt it and, anyway, that just isn't what 'Lusar' claims. He clearly wants us to believe that German cameras could "take 5,000,000 pictures per second". If 'Lusar' was a real person, recording what he believed to be true, then he was, technically, grossly incompetent. His claims for flying saucers and cameras are just two examples to which I can relate. There may be plenty more.
His agenda is made clear at the end of the book, saying that;
The achievements of the German people in the Second World War are almost beyond belief . . Confident of justice, trusting in God and Right the German people fought on with superior courage despite great difficulties . . the German sword had to break, since this was the will of Germany's adversaries.
I can identify no regrets here. Lusar appears to be an unreconstructed Nazi, indulging in the standard disinformation and propaganda that lay at the heart of that regime. He wanted the world of 1957 to think that the still-exciting flying saucer phenomenon was the work of his comrades, a touch of Nazi genius that outlived the war. And he was willing to deceive to achieve that end.
In my view, the confirmation from the 1957 AP release that Lusar mixed real and fabricated information in his book is entirely consistent with the rest of our knowledge of the 'Nazi UFO' mythos. The later development of half-baked flying discs bears no comparison to Lusar's claims. There is no more of a timeline between Lusar's 1945 flying saucer and real aircraft in the real world than there is evidence that the thing ever existed, let alone flew. I have no doubt that the claims of performance, at least, are lies, concocted by whom, and why, we cannot be sure. But if believed, they make the Germans - the Nazis - look far cleverer than those sick losers have any right to appear.
I have a simple proposition to make. Unless anyone can find a convincing, coherent version of the February 1945 test-flight - not of some half-baked US flying wing a decade later - then I suggest that this "flying saucer" account was a fiction distributed by Lusar, whoever and whatever he may have been, possibly based on the highly dubious account said to have been given by Rudolf Schriever in West Germany in 1952. I also suggest that both were later elaborated by 'Renate Vesco' in the late 1960s to include wildly speculative interpretations of the 'Foo Fighter' material which, by then, was more widely known, and to place the test-flight in the same month, but in 'Thuringia'. Since then it has been propagated by one insufficiently careful author after another, particularly in the entertaining, but hardly meticulously researched, work of W A Harbinson.
If this tale is to survive, it's time for somebody produced a credible, authoritative account that doesn't quote ludicrous speeds of travel and ascent, that has some clue about the mechanics of the craft's propulsion, and which, preferably, doesn't come from a source that claims to have been actively involved with the wartime Nazi regime. Similarly, in the context of the flawed nature of the rest of the evidence, any claim based on the existence of surviving film of wartime 'Nazi UFO' test flights would require substantial investigation to be regarded as credible, including an explanation of exactly who presented that material, and how it came to be on show.
It's important to try to get this right. It's no good our having some success in controlling the 'alien abduction' and 'secret government' myths if we just get stuck with a disinformation-based 'Nazi technology' one instead. Tim Good's latest book, the under-researched Alien Base, refers to 'Flying Saucers of the Third Reich: The Legacy of Prague-Kbely (pending publication) by Mark Ian Birdsall". Another forthcoming book may represent Lusar as authoritative, and further propagate as a revelation a view for which I have yet to detect any proof. That may only highlight my many shortcomings as a researcher, but unless some solid, testable evidence comes along to balance the blatant lies, I think that we have a responsibility to do now what is necessary to dispose of this crude confabulation before it has a chance to achieve a respectability it does not seem to deserve.