Flying Plank

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Aircar

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Feb 20, 2010
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Maybe Jim Marske or Al Backstrom (is he still alive?) could comment -- some information on design aims and weights etc would help also , You might not know that the Plank was adopted in Australia by then noted sailplane and airshow aerobatic pilot Fred Hoinville who had one built and was test flying it when he died in an accident unrelated (in a Fischer RW3 Multoplane) to the Plank. It is now in the gliding museum . There was also a side by side two seater Plank built and flown by Glideair sailplanes but it was never certified or produced beyond a prototype (there was no experimental category until forty years later here ) -- it would have been better built with staggered side by side seating for balance 0like the contemporary Schneider ES 52 Kookaburra trainer -- Topaz (Marc) has posted his design along those lines a couple of years ago and would be better placed to comment on your concept . I would suggest thinking about self launching and in that case the tailless configuration has a lot going for it as a pusher --the Fauvel website has details of his comparable designs and I presume you know of the Genesis development or the New Zealand design by Gregg Matheson (both tapered wings with higher aspect ratio and span ) --wing tip wheels might be a good idea to reduce ground loop risk also .
 

Stefan Franke

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Aug 28, 2011
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Jim already saw this. The goalwight was less than 120 kg... this week i opened the molds of the wings an what a desaster. they look pretty well but way to heavy. About 50 kg one wing. its a big surface and the wingtip is removable that causes wight also. The fuslage with 3 bulheads missing wights 12 kg. now what to do.
build a lighter wing, shorten the existing wing or build it like this and the wight is 140 kg. then i have to do normal ultralight registration in germany Here you can see some pictures of the fuselage and one wing...
 

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cluttonfred

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It looks great, like a modern, composite interpretation of the final version of Al Backstrom's EPB-1C Flying Plank.

10_Flying_Plank.jpg

I have often thought that a straight plank design would make a great, low-powered sport plane, essentially something very similar to yours but with shorter wings, more wheels and a small engine in the nose.

It would be nice to see a clearer drawing and hear how you have done the control mixing. I am assuming two elevons near but not at the tips and a Fauvel or related airfoil?
 

cluttonfred

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That Easy Plank design doesn't look so easy to me...forward sweep, much more complex controls and structure. Single rudder, straight plank designs like Backstrom's and yours are far more appealing to me: constant chord wing, rudder, elevons, spoilers or air brakes if needed on a glider, that's it. On a powered version without too high a glide ratio so no need for spoilers, you could easily get by with just three control surfaces, wonderfully simple. I look forward to learning more about your design.
 

marpbcn

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May 23, 2008
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Hello Stefan,

Very interesting design, I like it. I am curious, how is going the construction? what did you do, did you repeat the wing
 

BoKu

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Interesting, it looks like a neat project! I'm curious, why did you decide to use so many ribs instead of just using sandwich construction?
 

Stefan Franke

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thats the crazy part of the story...the guy who asked me to start a project with him thaught he could calculate a composite spar and wing.he told me to use this ribs and how to build the spar and the wingskin. unfortunatly i made it like he told me.
thats the reason why the spar and wing is so heavy. after he quit working on this project he told me that he is not used to composites....
anyway if this himg is flying i will build much lighter wings...


the wings you see on the photos the skin is sandwich construction.

too strong and heavy...
 

Growlzler

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Hello,
I started a post in the members log. i havent seen that there is no possibility to give comments aout the projekts...
Here is a Viewing aout the Wing when its ready
The short booklet "Experiment in Flying Wing Sailplanes" by Jim Marske, 1970 covers Backstrom's EPB1-A in his development of the Pioneer I. He also used a full flying rudder in the first design of the Pioneer but changed to a finned rudder in the "1A" version to "stabilize the rudder". The book as far as I know is out of print - excerpts seem to be available around the web and the original sometimes appears on an Ebay auction. Marske is currently working on the Pioneer III.

-Growlzler
 

Growlzler

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@Norman,

Nothing except the announcement by Kollman Composites concerning their teaming with Marske:

"Kollman Composites is proud to announce our teaming arrangement with Jim Marske, designer of the Monarch and the Pioneer sailplane. This teaming has resulted in the latest version of the Pioneer: The Pioneer III. Preliminary flight testing of the prototype Pioneer III has completed. The prototype Pioneer III delivered excellent performance with no surprises. Testing of the prototype will conclude in the spring of 2012. Confidence gained through prototype testing has allowed us to begin construction of the first production version of the Pioneer III.

A key design adaptation employed in the Pioneer III production is the standardization of the fuselage/wing integration. This will make it possible to employ the same fuselage with different wing variants. In addition, the information gained through flight testing of the sport wing will allow Mr. Marske to finalize the design of a high performance/race wing. The race wing will employ a fifteen meter span designed to maximize laminar flow; this will result in a glide ratio of 50+. The composite fiberglass construction will also allow for the addition of ballast tanks."


Pioneer ready built and kits available - Kollman site. Pioneer III kit $32,500. Take a look around seems there's progress.

The Pioneer III has the sky look of a high performance (~L/D 40+) sailplane. Could it be Marske has set his sights on a surprise appearance at the Nationals in the not too distant future(?)

This leaves open the question Marske keeps asking "Why hasn't anyone done this before"...,

Growlzler
 
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marpbcn

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May 23, 2008
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Hello Stefan,

How is you the construction of your flying wing, have you finished, have you flown it?

Best regards,
 
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