this looks like it might make an interesting model.  this was a German WW-2 design.

Tom Wilk

Hello Tom,
What a weird looking aircraft. It looks like one of Ray Maelstrom's designs. For those that don't know he was an avid freeflighter who designed some of the most off beat designs you could think of. They all seemed to fly brilliantly too!
What was the thinking behind this design? Some form of dive bomber?

Regards,

Andrew

Well, I'm about to give up. I have tried to post this twice, with pictures, but I wait a minute or so, only to get a time-out error message. Here goes again- without pictures.

That's the Arthur Sack AS-6, designed and built by a German farmer during WW II and offered to the neareby Luftwaffe unit. They took the time to test it some, but found c.g. problems and the expected lift challenges of ultra low-A/R designs. Their problems involved torque roll and inability to get high enough angle of attack to make use of the high lift coefficient available from the low-A/R wing. So it hopped and was damaged some. They changed the c.g. by adding weight, and if I remember correctly, moving the gear, but my simple analysis for David Myhra showed that the added weight about offset the advantages of higher a.o.a. It's been a while, but I did make a cursory analysis of this particular plane for author David Myhra some years ago, and he said he wanted to quote it in his book on the AS-6. I have not gotten a copy, but you might find it out there. If anyone's interested, I probably have that file somewhere and would be happy to forward it to you.

The Arups were created by Dr. Cloyd Snyder of South Bend Indiana, and numbers two and four were engineered by Raoul Hoffman, who wrote a lot of popularized engineering articles for Popular Aviation, which many years later became Flying magazine. They were excellent flying planes that unfortunately came along during the great american depression (1932-1935). So, despite the fact that Snyder was able safely and comfortably to take his kids up in iton flights around the midwest and sometimes far afield, he was not financially successful. A contemporary of Snyder's was R.B. Johnson who built a plane of A/R = 1, called the "Uniplane", whose failures ironically proved its aerodynamic success. It had so many engine failures that the safety of the configuration was demonstrated too often when lost power on take-off resulted in an unscathed Johnson upon turning back on climb-out (usually fatal in conventional aircraft) or settling in to small spaces. Later in the 1980's,  Elkhart's Milt Hatfield, who had traded his engine to Snyder for flying lessons with Glenn Doolittle, built three successful smaller "Arup" derivatives, two of them technically "ultralights". I visited him a few times and have a video tape of his "Little Bird #3" flights. All three flew well. Charles Zimmerman, who worked at NACA Langley in the 1930's undoubtedly saw the patent applications of Johnson and Snyder, since all aviation patents were reviewed by NACA. He then wrote NACA TR 431 and TN 537 on low aspect ratio wings and then created the V-173 and XF5U-1 "Flying Flapjacks'. Here are some pictures: AS-6, Arup S-2, Johnson Uniplane, V-173, XF5U-1 (one of many patent drawings for various aspects and mechanisms).  I have a video of the Snyder S-4 doing touch and goes at South Bend's Bendix field in 1933, showing its nearly STOL abilities and low landin speed (the Arups had marvelous flapless max/min-speed ratios).  I'll see whether I can insert a link to such a video. - SK

OK, I see the Sak AS-6 file was too large. Here's the rest...

Edit 2: Look at Feb 3 post on this link to see the S-2 fly. Note the climb-out:

http://www.homebuiltairplanes.com/forums/light-stuff-area/6570-low-aspect-ratio-ultralight-5.html

Here is Charlie Reeves' XF5U-1 that has been flown at several of the Tucson 1/2A Multi-Engine Profile Scale contests.

This won the Unlimited category last year.

Keith

the original ducted-fan aircraft

I've looked at this one before, and schemed about how it could be made to work and still look right.

You would have to make the forward fuselage (back to the wing spar) fairly stout, because if I'm not mistaken there is no spar carry-through through the center of the barrel.  Or you'd have to make the flying wires functional and let the wings essentially "hinge" on the fuse (which is probably what the original did).  Or you'd have to carry the spar through (ick!).  Bury the bellcrank in the inboard wing, with the pushrod, uh, somewhere.

It would probably be easier to make the fuselage with plywood rings in front, with stub spars sticking out to be captured by boxes in the wings.  You'd need one such ring in back for the tail, and clearly you'd need to exert some cleverness to get the motor mount working.

It'd be a great model to just fly around in circles and wow the crowd, although I don't think it'd work out as a semi-scale stunt plane.