Black Sun

Welcome to our forum. Feel free to post a message.

Forum: Black Sun
Start a New Topic 
BMW Flügelrad Eye Witness report

You write about the BMW Flügelrad that there's an eyewitness report of something that could be the Flügelrad.

As source you indicate: February 1989 issue, of the German magazine Flugzeug

The Problem: There never was a german magazine called "Flugzeug".
Could it be the "Flug Revue"?

I asked, because I wondered: In the report he mentions a drawing he made of the device ("See the attached sketch for the lower half."), but this isn't on the page. That's why I would like to know the source, so that I could look that drawing up.

Re: BMW Flügelrad Eye Witness report

Hi again,

I was busy in the meantime and organized several magazines which could be the right one:

- Tried "Flieger Revue"...nope
- Tried "Flug Revue"...nope
- Tried "Flugzeug Profile"...success!!!
"Flugzeug Profile Nr 23" page 23/24

And in it there's the pic as from the eye-witness himself. And it looks quite different than all the drawings.
(But it is definitely a Flügelrad and not another type of flying disc.)

I anyway just think all the "drawings" of these different types are rather imagination based on some explanations than based on real "drawings".

But the drawing as from the witness does make much more sense as the lower body is much bigger. You would anyway think seeing the "usual" drawings of the Flügelrad, that there's basically no room for fuel. But in the drawing from the witness the lower part looks very trapezoidal from the front, almost a rectangle. So there was enough space for fuel on the right and left side of the turbine...But is surely also created quite some drag...

My personal opinion:

I believe this eye-witness report is genuine. And it exactly matches what I would think of such a design: It's a very poor design, which behaves very bad, as described by the eye-witness. I do not believe it ever came further than hovering, so that it never "flew".
And I definitely do not think they every made further progresses from there but rather abandoned the project right there.
I could think that right from the beginning the V2 and V3 Flügelräder were just imagined progressions from it, basically for public relations purposes to get more attention and resources for this project.
I also think that BMW came up with this autogyro idea because Schriever presented them his ideas and wanted to have some engines from them. I think BMW immediately realized that Schriever's design was nuts as the forces on the rotating turbines would have been unbearable. That's probably why they came up with this autogyro idea by their own, which doesn't have the problem of the rotating turbines.

BTW: I think the same generally for the Schriever-type of flying disc. It just is IMHO a very bad design with many almost unsolvable problems (which are also just described like that in the test of their "first" prototype). The only design which does make sense IMHO was the Miethe design. And I personally think it was this design of which it was said, it flew very good at the end of the war, but used up huge amounts of fuel. As this is exactly what I would expect from the Miethe design.

And this is the design which was later copied and evolved by AVROE and then Bell (when the project got public).

As it seems to me already Miethe had in mind to make basically one big radial flow turbine out of the disc, instead of several single axial flow turbines radially arranged.

But I doubt they ever made this idea real, due to time running out...
But I think they rather wanted to make a big standard radial compressor, whereas AVROE changed this to a 6-stage-compressor with rotor and stator vanes as in an axial compressor but with a radial flow.
But also this design would have needed a lot of fuel due to the poor compression of just 3:1. But the flight performance would be awesome, as it is basically just one big giant flying jet engine...

Re: BMW Flügelrad Eye Witness report

Hi I just realized, that in the translation of the eye-witness report some details are missing. Especially one detail is interesting, namely the noise of the device (like an old motorcycle...).
So it seems to me he just saw a very early mock up, where they just used a piston engine instead of the turbine. It surely would have been enough for first rotation tests...

Here again the report as on your website but with the new additions by me, which were strangely not translated before as it seems:

Place of Sighting:

C 14 Flight School at the Prag-Gbell aerodrome.

Date of Event:

August/September 1943, supposedly on a Sunday (I seem to recall there were no services on that day). The weather was good, dry and sunny.

Kind of Observation:

I was with my flight comrades on the air strip, more precisely, near the school buildings, some 2000 [200m not 2000]meters away from the arsenal [shipyard](located to the extreme left). See adjoining diagram.

The device was inside the hangar: a disk some 5-6 meters in diameter. Its body is relatively large [small!!!]at the center. Underneath, it has four tall, thin legs. Color: Aluminum. Height: Almost as tall as a man. Thickness [of the disc]: some 30 - 40 cm., with an rim of external rods [[instead]fanned on the outer rim], perhaps square orifices.

The upper part of the body (almost a third of the total height) was shrunken over the upper half of the disk. It was flat and rounded. See the attached sketch for the lower half.

[[instead]The upper part of the body (almost a third of the total height) located above the disk,was flat and rounded, the lower part was bellied, See the attached sketch]

Along with my friends, I saw the device emerge from the hangar [[instead] I saw how the device was pushed on the forefield of hanger]. It was then that we heard [[instead] a loud rattle] the roar of the engines [it sounded like starting an old motorcycle], we saw the external side [[instead]rim] of the disk begin to rotate, and the vehicle began moving slowly and in a straight line toward the southern [southeast] end of the field. It then rose almost 1 meter into the air. After moving around some 300 meters at that altitude, it stopped again. Its landing was rather rough.

We had to leave the area while some custodians [attendants] pushed the vehicles toward the hangar. Later on [we have been told], the "thing" took off again, managing to reach the [other] end of the aerodrome this time.

Afterwards, I made a note in my flight log of the members of the FFS C14 who were present at the moment: Gruppenfluglehrer (group flight instructor) Ofw. Michelsen; Fluglehrer Uffz. Kohl und Buhler; Flugschüler (flight students): Ogefr. Klassmann, Kleiner, Müllers, Pfäffle, Schenk, Seifert, Siebert, Squarr, Stahn, Weinberger, Zöbele, Gefr. Hering, Koza, Sitzwohl, Voss, and Waluda.

[some name corrections made...]

Re: BMW Flügelrad Eye Witness report

Sorry for spamming, but one detail really baffles me about the witness report.

He clearly states that only the "outer rim of the disc" was fanned. If I look at all the pictures of it, I wouldn't say that there only the "outer rim" is fanned, when basically 2/3 of the disc diameter is fanned.

And especially baffling to me is that he describes the openings as square (quadratic as direct translation, as square is a bit ambiguous in english).

If it looked like on the pictures, then IMHO there's no way he would describe these fans as quadratic.
But OTOH we basically know, that all the known pictures of it are just imagined illustrations as it is known, that all original data has been destroyed at the end of the war.
So I personally would rather suspect that the disc looked differently than in all the pictures, much less like a giant fan, but probably more with just fan vanes really only at the rim part. This would certainly be much easier to construct in a mechanical way and it would also make sense due to lift, as the smaller slower inner part of every fan would deliver almost no lift compared to the much bigger outer section.
So maybe they designed it that way, that there was some fuel in this inner rotating part.
As advantage of this I would imagine, that the inertia upon starting would be huge, and that would be exactly what was needed for take off.

Additionally I do think as the thing should act like a normal wing during level flight, that the cross section from the rim to the blades to the rest really looked like a continuous shape, not like in all the drawings.

Just some thought...