by Rob Arndt
by Rob Arndt
The original propulsion units slated for the Schriever Flugkreisel were to be five BMW 003 jet engines with three units arranged on the disc rotor and two units on each side of the disc underbody. However, as BMW learned of Schriever’s original design the company started internal development of its own smaller-scale versions of the new “disc-fan” technology.
BMW Flügelrad I V-1
Art by Justo Miranda
Work began in 1943 with the BMW Flügelrad I V-1 (Versuchs or prototype 1) which was painted matte aluminum and performed its first flight tests at the Czech aerodrome at Prag-Kbley between August and September of that year. It left the hanger by its own means after which the rotor began to spin under the power of the Strahlrohr (Jet Pipe) deflector. Lifting to 1 meter and flying for 300 meters before making a hard landing. During static testing the prototype was surrounded by concrete blocks to prevent the test pilot in the unfortunate event of a disc blade breaking.
In general appearance the Flügelrad lay-out was of a central body housing a single pilot covered by a hemispheric dome surrounded by a disc blade rotor of 6 meters with a lower body housing a BMW 003 jet engine, fuel tanks, a Strahlrohr deflector and fixed landing gear of four legs fitted with wheels but no brakes nor shock absorbers. Flight was achieved by jet exhaust deflection into the 16 variable-pitch disc blades with hydo-pneumatic actuators.
BMW Flügelrad I V-2 minus tail rudder and painted yellow
Art by Richard Lewis Mendes
The first design was very crude so work proceeded on the second prototype designated BMW Flügelrad I V-2 in 1944. This time, the cockpit was enlarged to house two pilots and serve as a support for the addition of an aerodynamic rudder for better control. The fixed landing gear was replaced with a more practical semi-retractable one. Rotor diameter increased to 8 meters but kept the 16 disc blades. This machine was painted yellow and performed its first flight tests in late autumn 1944 at the Neubiberg Aerodrome near BMW’s Munich facility. Severe stability problems plagued the machine and the rudder proved useless.
Possible constructed BMW Flügelrad II V-2 in flight, April 1945 - powered by underbody
BMW 003 turbojets
Not to be deterred, BMW built another prototype designated BMW Flügelrad II V-1 in 1945 which kept the same body but discarded the failed rudder. The disc rotor was enlarged to 12.6 meters. The first test flight was again performed at Prag-Kbley in February 1945 with another jump at low altitude but without the ability to actually fly.
Meanwhile in 1945, another BMW Flügelrad prototype was under construction and may have possibly flown during April 1945. This was the BMW Flügelrad II V-2 which was powered by two BMW 003 jet engines located in the lower body side-by-side. The cockpit was enlarged for a crew of four and rotor diameter increased to 14.4 meters with 24 disc blades.
BMW Flügelrad III stratospheric recon disc
Art by Justo Miranda
A further BMW Flügelrad II V-3 was in the model phase and differed from the V-2 version in having 21 disc blades.
The final model, the BMW Flügelrad III was in the design phase and would have been the anticipated production model - a huge stratospheric reconnaissance aircraft powered by two BMW 018 jet engines each with twin Strahlrohrs, one engine mounted over the other in an upper and lower body. The upper and lower body would accommodate 6 crew, an enlarged 24 meter rotor with 32 disc blades, fully retractable tall gear, and room for an impressive array of cameras including infrared types.
Nevertheless, all work ceased on the Flügelrad development programs in the Russian advance. All prototypes and documentation was ordered destroyed by the SS.
As Schriever’s own failed Flugkreisel was also testing at the Prag-Kbley facility it too probably was destroyed. This machine was distinct from the Flügelrads by both its greater size, different configuration, and the tremendous roar of its five kerosene-burning jets that no Flügelrad possessed. Furthermore, Schriever’s Flugkreisel could actually fly while most of the Flügelrads could just barely hop or were tethered.
In its February 1989 issue, the German magazine Flugzeug published the following report made by a German aviation official who, allegedly, been the protagonist of the astonishing sighting involving a "flying saucer" at the Prag-Gbell (formerly Praha-Kbely) aerodrome in 1943. The controversial report follows:
In the top diagram the hangar which was the site of the research is marked as number 2.
The same hangar is indicated in the picture below with an arrow
Flügelrad I V-1
Flügelrad I V-2
Photos courtesy of Allen B. Ury