This a shot of the Aero Synergie Papango ultralight, the succesor of the Aero Synergie J300 Joker.

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The wings are more elaborate compared to its predecessor's and include on their top two additional extensions/devices.

What are they? Any aerodynamic role or just for aesthetic sake?


1 Answer 1


Those are wing fences and they prevent airflow perpendicular to the direction of travel. This isolates the portions of the wing and allows the inner wing to stall independently of the outer wing.

Since the wing uses flaps, the inner portion will create more lift and stall (separation of airflow on the upper wing leading to loss of lift) at a lower angle of attack. Wing fences prevent this stall from extending over the outer part with the ailerons, so the airplane will stay controllable in a stall and will not suddenly drop one wing.

  • $\begingroup$ Why is that a benefit? $\endgroup$ May 5, 2014 at 13:50
  • $\begingroup$ @GrahamBorland it is more beneficial for swept wings, but because the isobars don't need to be in line along the whole wing you can get away with more $\endgroup$ May 5, 2014 at 13:55
  • $\begingroup$ I must be missing something - wings can stall? I thought engines stalled... How can part of a wing stall when the rest of the craft hasn't? Aren't they all travelling at the same speed? Or is that something that kind of deserves its own question... $\endgroup$
    – corsiKa
    May 5, 2014 at 15:35
  • $\begingroup$ @corsiKa when a wing loses lift that is called stalling, and the different aerodynamic properties of where the flaps and ailerons are is enough to provide different stall characteristics $\endgroup$ May 5, 2014 at 15:42
  • $\begingroup$ @corsiKa: See en.wikipedia.org/wiki/Stall_%28fluid_mechanics%29 $\endgroup$ May 5, 2014 at 16:52

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