"snip"
I would expect the higher aspect ratio tail to be more effective as a lifting surface, thus probably requiring less deflection - thus less drag in corners, not a bad thing, eh?
Missed this one back when it was active.
Mike's comment in the snip above is pretty much the best answer to his question of the thread.
The effects of aspect ratio are pretty much the same regardless of where the surface involved is attached to the airplane. The most important part of selecting the "best" for your purpose aspect ratio is that the resulting delivery of lift per unit of angle of attack best suits the task of the airplane in question.
Aspect ratio can best be understood by checking out the full scale airplanes designed for specific purposes. Mike's description in the "snip" above is as good a one as we require. High aspect ratios of a given area will produce a "given" amount of lift at a lower angle of attack (or in the case of tail-planes, elevator deflection) and produce less induced drag (drag that is the product of the lift delivered) than lower aspect ratios while doing so.
This is why you see slow flying sailplanes with very high aspect ratios (and no "motor/engine" to overcome additional drag) and high speed jet fighters with very low aspect ratios (with ton's of thrust to overcome the additional drag and still maintain those high speeds).
When speaking of "tails" for our stunt ships one needs to keep those factors clearly in mind. The amount of tail lift to provide the desired corners will be ~more or less the same whichever aspect ratio you select. The difference will be how much deflection is necessary to achieve the necessary "moment" about the CG to provide the desired rate of pitch change of the ship.
If you have lightning reflexes and the ability to build a very high aspect ratio stab/elevator at adequate rigidity (to prevent flexing) the amount of deflection necessary to achieve the desired pitch change will reduce dramatically the higher the AR gets. In addition, the pilot input force necessary to get that lift increase at small deflection will be "much" less the higher the aspect ratio. These combined factors less force required at lesser deflection to obtain the necessary lift for the desired corner will rapidly get to the point that the airplane track in pitch (maneuvering) will become very difficult to control...more lift at less deflection at some early point will require less and less line spacing at the handle further lessening the pilot "muscle" necessary to produce the desired pitch rate/corner size let alone fly smooth consistent round loops!!
The opposite--very low aspect ratios--will require much greater deflection and produce much more drag to provide the same lift to obtain the desired corner...and will quickly bring the Netzeband wall into play (not enough line tension to allow the necessary deflection to to obtain the desired/necessary aircraft pitch rate for the trick. (more discussion available if some aren't able to "think" the reverse of the effects of high aspect ratios).
Finding the best balance between the two options (different people might well have different preferences on aircraft response rate) is one of the important "fine tuning" factors in producing a stunt ship that responds as desired using the control inputs (both amount of deflection and [pilot] energy) to achieve it.
What successful designers have done over many years (even if they didn't realize it) when developing a career's worth of design refinements is experiment with the endless variety of options obtainable to find the ideal (for them but generally satisfactory for most) combination of these factors (and, IMPORTANTLY, the total tail area as a percentage of wing area and CG location) best suited to take advantage of those factors.
My designs starting with the Imitation/Excitation were a foray into this exact subject matter and several other design factors, wing area/aspect ratio/flap area/chord percentage, etc. David fitzgerald's Stunt News article "D'Tails" several years back also includes excellent discussions of the subject matter.
These factors are an important part, for instance, of my discussion of
design parameters touched on in my opening post of the At The Handle Forum;
"Some fresh thoughts on “Where/How to look while flying".
Once again, sorry for the length. Once I get started it seems my fingers take on a life of their own1
Ted