susquach

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Just wonder'n.....how a thermal ship would fare with ailerons/elevator only. I'm aware that a few plane types get along just fine without one....but I can't remember ever seeing a thermal type plane sans rudder. Specifically, what interests me is the advantage of a considerably lighter tail (no control rod, hinges, horn or rudder structure). Is there anyone flying slope/thermal who can shed some light on the matter?

daveosoar

Many slope gliders use ail/elev systems only, remember that aileron is ROLL and rudder is YAW, in thermal conditions a judicious of both, together with some elevator input will result in aFLAT turn. In TD flat is paramount, lose a metre in a turn and its lost forever.
Daveosoar.

OzMo

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What Daveosoar said,
High dihedral or polyhedral wings tend to roll in a rudder turn to a degree that ailerons are not required and I read here the may not have much effect in that configuration either. In the flatter wing setups ailerons are essential.

so like what the oldest women in the world wears on a date........JUST DEPENDS LOL

susquach

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Thanks guys.

SoarLA45

Flat wing aircraft require a more yaw than rudder only can provide to turn. If you use the ailerons carefully, you will have no problem thermalling.

aeajr

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Many thermal pilots fly without using the rudder. It is likely they are flying less efficently than they could, but the fact is that rudder is optional on an aileron ship. But rudder helps you fly more smoothly, more efficently and more effectively.

So, yaw or not, thermal soaring is still a blast!

BMatthews

A local guy flew a 2 meter with aileron elevator only a bunch of years back and I later followed in his footsteps. It worked just fine. However I will add that you will probably want to fine tune the size of the vertical tail to get a nice neutral handling model. But it will work and work just fine including perfectly normal winch and high start launches once the model is moving.

susquach

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HUMMMM...the plot thickens...as they say. It's interesting to read some experiences of folks who have done aileron only soaring.

What got me curious about the prospect of flying just ailerons is a 4-channel HLG that I've been enjoying. I relaized one day that I was inadvertantly using only the ailerons only to steer. Normally I coordinate rudder/aileron so rather than correct my style, I just kept using aileron only, to see what the result would be. Frankly, I couldn't tell much difference outside of the finesse aspect that AEAJR mentioned. Rudder definitely adds nuance and outright steering authority. BTW, my HLG has minimal dihedral.

I suspect BMATHEWS has the remedy to "balancing" the performance of a rudderless plane...that is "trial-and-error adjustment of the vertical surface area to fine-tune the way a plane performs in thermal.

The issue got me interested enough that I began using just aileron on my sport plane...a Blue Max......with swept wings, sans dihedral and not an overly large vertical surface. The plane has almost no use for a rudder. is very sensitive to roll inputs. If I could get a sailplane to handle with the same smoothness and authority...with so little control throw (read drag) I'd be dowright delirious. However, the areas that rudder is essential is crosswind landing, slipping to lose altitude and fine steering some aerobatic manuvers....and stall turns....and taxing ( not one of yer more useful sailplane attributes).

And going back to DAVEOSOAR said...it's hard to get around the "flat turn" aspect of rudder control. Guess the hope would be that drag created by a "roll/aileron" turn would be offset by the lighter weight and more responsive performance of ailerons.