Designs using auto stable airfoils

also called unswept flying wings

These designs use an airfoil, which doesn't require a sweep. Therefore they are the most compact version of a flying wing. Fauvel, a French designer, became famous with his unswept designs. These designs are without vertical tail very unstable, so most designs have a vertical tail.

This airfoil (CJ-5) is an example of an auto stable or reflexed airfoil. Note that the trailing edge goes up. You can see a reflexed airfoil as a normal airfoil with a tail-airfoil in one.

The most remarkable airplane in this type is for me the Facet Opal. It is tiny, but ... it is fast and have a unexpected range. It was a real record-breaker. You can read more about it. Just click the picture below.

 

The Debreyer Pelican

The Debreyer Pelican, a compact ultra light, uses the 17% thick Fauvel reflexed airfoil. "Ideal for a beginner" as the manufacturer says. Click here to go to a page about this remarkable airplane.

Marske Pioneer

Marske Pioneer, available as kit and on plans (picture given by Buddy and Lloyd Watson) Go to site of Kollmanwings where they construct the Marske designs (www.kollmanwings.com) and also see the Marske Monarch.

 


Fauvel made several flying wings with autosatble airfoils. More info about his work at http://www.nurflugel.com/Nurflugel/Fauvel/e_index.htm .

Advantages:

  • Less work on basic design. You don't need to calculate twist and sweep.
  • Compact. Since (mostly) no sweep is used, these designs are easy to place in a hangar.
  • No sweep means no difficult main spar connection.
  • Auto stable means no stall and no spin. The condition is that the CG (centre of gravity) is placed on the right spot.

Disadvantages:

  • Reflexed airfoils have less lift than normal airfoils. So more wing area is needed to have the same lift.

More videos:

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    The Opal Facet was a remarkable airplane. It set a few records. Don't underestimate it. It is small, but ...fast and it had a impressive range. I made a special page about this one. Go see the Specials.

I made a special page about this one. Go see the Specials.
It is a RCmodel. Look ... it has no verticals!! This was possible by using a Bell Shaped Lift Distribution wing. BSLD. Go read about Horten and Prandtl to understand more about it. Use the tool of Marko Stamenovic to make your first models. It is in this section too. Name is Flying Wing Designer.
Youtube videos i found about flying planks.
If i find more youtubes, i will add them here too. Hints are very welcome.  :)

Ending the discussion about flying planks and poor pitch-stability

I guess many of us have read in forums that flying planks are very pitch-unstable. And they are more than a handfull in turbulences, because they have a very short arm of moment of the control surfaces. Well, i dared to ask it to Mike Whittaker, who designed and build the MW9 Plank. You can read his experiences about pitch stability at the end of the special page about his airplane.