The referred to picture is a photograph taken under less than optimal conditions of an airplane with a circular bearing surface with the Luftwaffe colours of the Second World War. This "Fliegende Bierdeckel" as it was called at the time makes a martial first impression heightened by the cockpit cover resembling that of the Me-109. The use of a wooden propeller and an obviously fixed landing gear with spur makes it evident that it could hardly have been intended as an opponent of Mustangs, Spitfires and Thunderbolts although the designer of this strange aircraft intended it for military employment (at least for its successors developed from this prototype).

The story of this disk begins quite harmlessly, when the farmer Arthur Sack of Machern near Leipzig decided to seize upon the not quite new idea of the Kreisflügler and to realize it as a model for the time being. We do not know what finally inspired Arthur Sack but there were plenty of precedents. For instance the Discus, the throwing disk of ancient classical history or the constant reports over the centuries of ‘Flying Disks’ – even today these sky phenomena appear regularly in the media as UFOs. They are not included in aviation history since the theory that these sightings for the most part are due to  natural atmospheric phenomena is gaining more and more ground (?). Possibly disks like the UFOs have stimulated the construction of similar manned aircrafts. In the 19th century in Germany, the now forgotten mathematician and aviation theoretician August Wilhelm Zachariae experimented with circular load bearing models. Around 1911 in England an aircraft with a circular ring wings build by Lee Richards was said to have managed a speed of 130 km/h and a landing speed of around 35 km/h. For aviation construction in just the beginning stages these were fantastic achievements. In the early 30s a ‘Circle Plane’ was build in the US, where the circular load bearing surface was mounted on a conventional fuselage. This airplane was reputed to have had very good short landing qualities. The American H. Zimmermann proceeded in a more scientific manner when he conducted wind tunnel experiments in 1932 with extremely shortened wings; the results published in “Technical Report 431’ of NACA (now NASA) caused some attention, led to a patent (USA 2.108.093) and later found practical appliction in the "Chance Vought 173" (first flown in 1942). In Germany it was no less a personage than Dr. Alexander Lippisch who since the beginning of 1939 at Messerschmitt in Augsburg developed his Delta Rocket Interceptor Me-163 to the point of readiness for mass production and who, as a side line to this had the Kreisflügel 1940/41 tested in the wind tunnel of AVA in Göttingen, but without achieving any spectacular results.

These cited prototypes and projects are the exceptions in aviation construction. Airplanes with circular bearing surfaces are so rare, they are barely mentioned in aviation reference books. Too many drawbacks are ranged against their use For one thing their structure and thus their construction is quite complex. In addition the circular bearing plane without the aid of supplementary complicated propelling equipment has no aerodynamic advantages over the conventional airplane. To return to Arthur Sack’s labours – he began realization of his idea around 1938/39. When he demonstrated his Model 1939 the fortunate coincidence of the Generalluftzeugmeister’s presence came to his aid. Udet was so impressed by the idea of a militarily operational Flugscheibe that promised to pass unhindered through the current defensive balloon barrages, he at least eased Sack’s way to further trials. The demonstration of the model occurred during the "Erster Reichswettbewerb für Flugmodelle mit Verbrennungsmotoren", July 27 and 28, 1939 in Leipzig-Mockau. The participants were given the assignment to carry out an aimed flight with return to the starting point using the most simple directional guidance systems. The contest was carried out in a low-key fashion, excluding the public. That soon proved to be a wise decision, since this first attempt to come upon a tactical usable Mini Reconnaissance Aircraft via model flights turned out to be a total failure. Most of the models were equipped with so-called ‘self steering devices’ which did not function while the engines were engaged. The only true remote controlled model of Sinn crashed at the start and the steam turbine equipped model of Scholl burned up during the heating up process. A full-fledged fiasco. Sack too had problems with his ‘Flying Beer Coaster’. His model, starting without competition, could not break free of its earthly bonds despite several attempts and had to finally be launched manually by its builder. The powered flight, lasting several minutes, took the model, labouring heavily due to faulty trim but, nonetheless flying stable, to heights of some hundreds of meters. The final ‘glide landing flight’ scarcely deserves that appellation – the model came down heavy like a ‘piano in a weak thermal layer’. But these were mere shortcomings, which Sack during further flight tests after the contest could easily remedy. The diameter of the Kreisflügler was 1,250 mm, its weight about 4,500 grams. Apart from its circular shape and the unique demands caused by it, the flying disk corresponded in its technical data to other conventional types of the time. A suspended Kratmo 30 Motor of 0.65 horsepower at 4,500 rpm with a propeller of 600 mm diameter served as propulsion. This 30 ccm engine soon discontinued by the manufacturer because of its high weight and low output was not in common usage with the model flyers of that period since, like most other German motors, it did not start easily. Nowadays the Graupner Wankel Motor of only 4.9 ccm and weighing 335 grams delivers the same performance!

As far as can be established to date no design drawings of the models demonstrated by Sack in Leipzig-Mockau exist anymore. Since it was described and pictured in several newspapers of the time it is possible to reconstruct a provisional multi-view picture to show the general details of construction. It shows that at first Sack intended an altitude rudder to provide greater flight stability. The raked fuselage reminiscent of the WW 190, proved to be unsuitable for starts and should also be of little use in landings. Arthur Sack build four more models before he proceeded, mid war, to the realization of a manned aircraft. Because of the private basis of his project he was naturally dependant on the help of specialists. Initially statistical assessment and then construction was carried out with the aid of an engineer of Mi-Mo ((Mitteldeutsche Motorenwerke) in Leipzig.  The further construction of the plane with the designation AS 6 was completed with the help of the Flugplatz Werkstatt Brandis by the beginning of 1944.  The airplane was equipped with an Argus 10 C engine of 240 hp and had a circular surface with a Göttinger profile and a diameter of 6.4 meters. With an estimated flight weight of 750 to 800 kg the bearing weight would have been about 25 to 30 kilograms per square meter, something in the range of a Klemm 25 D. Since Sack himself was no flyer he had to search for a solo pilot. In the beginning of February 1944 he approached the chief pilot of ATG in Leipzig and asked him to test fly the airplane. (The ATG, formerly DFW, during the war build the Ju 52/3m and Ju 88/188/388 under licence). With the agreement of the ATG, Chief Pilot Baltabol began his employment at the beginning of April 1944 with a ‘ground inspection’. Baltabol reported: “The airplane, to the eye, made a good impression.  Despite it being a hobbyist construction, of course also using the resources available to the Aviation Center at Brandis, one must definitely declare it of superior workmanship.” With the first attempt of an in-flight loop it turned out that the arrangement and adjustment of the pedals were badly chosen and that the full side rudder had no braking qualities. The breakage of a landing spur brought the first test to a premature close.  

After the spur was reinforced and equipped with a steel rail as a backbone and the pedals had been adjusted more usefully, the testing could continue. Even though lateral direction guidance proved to be heavy, Baltabol carried out 5 starts on the 1.2 km long runway of Brandis. All five attempts remained  unsuccessful because the plane porpoised and over-reacted to the lateral rudder. To add insult to injury the leg on the right side of the landing gear broke during the last start attempt. During the repairs a suggestion of the pilot to move the landing gear provisionally back 20 cms due to high tail heaviness, was considered. Because of construction reasons this was unfortunately not possible, it had to moved back a full 40 cms. As a result the plane during taxiing star became so front heavy that the pilot refused to take responsibility for a start,  more so since new alterations in the cable arrangements for the side rudder and the pedals made application of the brakes impossible. Thus more changes were necessary. After installation of a brake system from a Ju 88 and the addition of 70 kg ballast just in front of the side fin, as well changes in depth of lateral and vertical rudders by about 20 mm through the application of stripping the aircraft was once again ready to start. But that start also failed. With a front heavy trim the airplane, even after taxiing 600 meters (!) still showed no inclination to leave the runway. When, after the second attempt, it turned out that the motor had much too little performance the testing had to be interrupted once again. After remedying all shortcomings the decisive start attempt was made on April 16, 1944. in almost dead calm weather the machine was rolled to the furthest edge of the 700 m long runway. When Baltabol opened the throttle, the AS 6 did accelerate extremely quickly – but once again showed no inclination to launch after 400 m, even though the pilot pulled gently on the joystick. Only after 500 m did the violently swaying plane make its first tentative hop, and while the pilot was still trying to compensate for the sway, it already alit again. Since the end of the runway was approaching threateningly Baltabol had no choice but to terminate the start. At the next start the pilot aided the launch by rolling the machine at a somewhat higher angle. Even though a somewhat longer ‘jump’ resulted, the machine did not gain altitude even at high rpm. A continuation of the start attempts was no longer possible that day, since the propeller had been damaged due to strong tilt of the plane while rolling. Baltabol suggested  increasing the output of the motor, that in his opinion was inadequate, and if a renewed start should fail to have the plane checked out for its start and landing capabilities in a wind tunnel.  

The tests so far had proven that a decisive flaw existed, one that in all likelihood could only be remedied by wind tunnel testing. That exceeding Sack’s opportunities. However he did not give up but tried to solve the problem by conventional means. When in Summer 1944 the first group of JG 400 with Me-163 were stationed at Brandis, Arthur Sack once again began a search for a pilot. Even though the men of JG 400 with their Me-163, the fastest plane at that time and perhaps the most critical, had seen a lot, even they became sceptical when they saw Sack’s "Bierdeckel". Nevertheless an adventurous pilot was found in the person of Oberleutnant Franz Rösle who was willing to venture the start. But already at the first roll-out there was new drive-train failure. With that the career of the AS 6 V1 appears to have ended, since during  the last difficult war months every man was needed, especially in Brandis. 

To round off the story, it must be mentioned that an eyewitness claimed to have seen a circular load-bearing plane in the autumn of 1944 at the airport of Neubiberg near Munich. The aircraft was painted yellow. The question if it was the AS 6 V1 must remain open. Its not unthinkable, since Arthur Sack proved that he pursued his ideas with fervour with his construction and ongoing testing, although without success. All that without the support of the RLM and in times of war! Why should he not have been to bring the plane to Southern Germany for wind tunnel trials? Maybe the machine came under the aegis of the Luftwaffe and was relocated from Brandis. 

This revelatory article was accompanied by three b&w pictures, two of which show the original plane as Walter Zucker and Wolfgang Späte were able to photograph it. The third picture is of a display model by Hans Justus Meier, demonstrating how the AS 6 would have looked. Also a comprehensive drawing found its way into publication, one in which Peter von Schalscha-Ehrenfeld is said to have had decisive input. As a bonus a sketch of the Wind Tunnel Model J 1253 from the period of 1940/41 ordered by Alexander Lippisch is printed; not an airplane model but a wind tunnel prototype of a pure discoid wing shape. Furthermore, there is an autobiography of the authors, to show which publications had already reported on Sack’s work:: Der Flieger 11-12/1940, Modellflug 9/1939, with picture; Der deutsche Sportflieger 11/1939, Der deutsche Sportflieger 9/1940.  The photograph by Walter Zucker already appeared in the English magazine RAF Flying Review  during the 50s. This picture was then used in the book “Das Buch der deutschen Luftfahrttechnik", Mainz 1970, by B. Lange with the following caption: “An unidentified Kreisflügel Flugzeug of the Second World War”. Späte’s photograph first appeared in Der Flieger 4/1977 with the notation that it was a private construction with which repeated taxiing and start attempts were made in Brandis. As can be seen the idea of this Flying Disk was quite well-known in aviation enthusiast circles in the early 40s: it is no wonder that thinkers, hobbyists and inventors, without having Sack’s possibilities, sat down and wove all sort of thoughts about this kind of aircraft, thoughts that were later brought into circulation as ‘Factual Reports', without ever achieving the status of Sack’s AS 6 V1.

The Journal für UFO-Forschung (JUFOF) in January 1980 published “Test Edition 1”, letter sized, mimeographed one-sided. It took over for the GEP Nachrichten, and the test issue was to establish if a further publication of the GEP internal newsorgan was worthwhile at all. In this edition Hw Peiniger concerned himself with the question “Were there Flugkreisel in Germany”. He made it clear that Schriever’s Flugkreisel was never flown and that an examination of press reports regarding it show “many discrepancies”.

The Neue Presse of Augsburg on 2 Mai 1980 had sensational news: The Father of the Flying Saucer is a Long-Time Augsburg Resident / Hein­rich Fleißner (76): I Could Build the Jet Disk Again Anytime / Americans Snapped Up Patent for the Super Machine reported Reinhardt Sandner:

It was not that easy to track down the inventor –or at least the father of the idea of a flying disk- of the ‘Flying Saucer’. But now the 'Neue Presse' can lift the veil of this “UFO” secrecy, that the constructor and multi-patent holder Heinrich Fleißner is no ‘greenhorn’ as his birth year, 1904, can attest. Exactly 25 years later this ‘inventive spirit’ who had been intensely involved in fluid dynamics, of both water and air, took out a patent on a "Ro­ta­ting Jet Air­craft with Lif­ting Disc Wing and Cen­tri­fu­ging Tanks". Years later, when the war threatened to lift the whole world from its hinges, this Jet Disk became of interest to the Luft Waffe as a Courier Transport.  Hermann Göring, despite a construction prohibition by Hitler for whom ‘the thing was too fast’ declared himself as a proponent of this aircraft, which could reach speeds of 3,000 km/h within earth’s atmosphere and up to 10,000 km/h outside. One example makes the unimaginable clear: circumnavigate the globe in four hours. The ‘brain’ of the technical developers was in Peenemünde, the component parts were assembled in different locations under the strictest secrecy. Fleißner acted as Technical Advisor. He can not provide proof of these flight capabilities to this day, although he knows an eyewitness who reported the following to him: “Shortly before the capitulation, on 24 April 24 1945 a Staffel of four Flying Disks, each manned by two pilots (names unknown), started from  the Berlin-Lichterfelde under heavy artillery barrage from both German and Russian sides for a goal unknown even today.”

Hein­rich Fleißner (76), born in Augsburg, and now living in a small village outside the city talks about his legendary machine like an auto mechanic about an engine. To him this revolutionary development is almost something commonplace and he only wonders “why there is no interest in it nowadays.” Of course he had to relinquish his patent to the Americans in 1954, without remuneration. The last detail, the total concept, however is still locked in his brain. Answering the question if he could still build a ‘Flying Saucer’ today, he said, “Saucers only fly inside the home – but, all joking aside, I believe it would be possible anytime.” The costs may be prohibitive, since “even then one of these aircrafts cost forty million Reichsmark.” He gave up on the idea of finding sponsors to present a model at the aviation show years ago. The phenomena also attracted the attention of the Messerschmitt Test pilot Fritz Wendel. The legendary world record holder, also a native of Augsburg had raised doubts that the technology of the 40s was capable of building aircrafts with such speeds. Some years later the District Attorney, according to Fleißner had to return the supporting documents – “without rebuttal”.  Some easily understood techbical details will make the ‘UFO’ comprehensible to the layman. The rounded tanks were filled separetelly with Hydrogen and Oxygen. Once the jets were open there was an explosive combustion – creating propulsion. While the outer disk rotated almost silently, the pilot’s cupola, with a 360 degree view, remained stationery. A landing of the ten-meter in diameter disk was possible everywhere, on land or water, without problems.  The retractable undercarriage legs terminated in inflatable rubber cushions enabling swimming or soft landing. After the war, as per Fleißner, all documentation was destroyed by the Deutsche Wehrmacht. Only a few useless design drawings fell into the hands of the Russian occupation forces. If unidentified flying objects are observed today, they well be ‘descendants’ of Fleißner’s original idea. Thus the veil of the unknown continues to exist, since even Fleißner declares, “We do not know what’s hidden behind the Sun.”

This headline story was accompanied by a reprint of a patent drawing of a "Rotating Jet Aircraft with Lifting Disc Wing and Centrifuging Tanks" by an H. Fleissner. The submission was made on 28 March  1955 and received the US Patent number 2.939.648 on 7 June 1960. Fleißner’s version is incorrect, whereby his patent was allegedly already filed 1929 in Germany, and led, supported by Göring, to the German Flugscheibe (with an unbelievable price tag of 40 million Reichsmark!) only to be taken from him by the Americans – after all the patent, from the beginning, was under his name. It looks more like he could not pay the appropriate patent fees and so simply registered his double-sided (!) patent in the United States.