Milton - I'm as much of a BigJim fan as you, maybe more, but that doesn't wash. If it was a design flaw, ALL AVANTI's would hunt, not one, or some. All Banshee's should have the problem too, not just yours, or a few, or some.
I agree with this statement. I think I was trying to say the same thing, but maybe I did not do a very good job. So much is lost on internet posts... A lot of "Texas logic" is thrown about in stunt. This is the logic that "what you see much be true", then reasons are invented to explain it.
"So and So had one of those and it hunted like crazy, must be that inline stab".
"So and so won the Nats with that design, it must be better than all the others"
"That guy was using a 6 pitch prop and I saw it wind up and he lost the contest, low pitch props are better in the wind"
The opposite is true when someone sees something going the other way...
"That Yatsenko plane flies great in the wind, what the heck??? How can that be happening??? I heard they use 6 pitch props, forward CG's, and little bitty stabs and those don't work." (BTW, I heard this a lot at the Muncie WC's).
I think that there are few elements to most design discussions:
1. Design, power train, patterns, etc are a regional phenomenon. If you were to come to Texas 6 years ago, chances are that a large contingent of fliers would say that you needed a Bear, a PA, and 4 blade prop to be competitive (this was the case for me when I moved here). If you attended the NW Regionals 10 years ago, I am sure you would have heard the same thing about a TP, Impact, and an OS VF. Same could be said for a Greenaway design, and ST 60 if you went Northeast, or an SV-11 in the Southwest. Now there is a whole new region called "the rest of the world" which has chosen to embrace a whole different set of design parameters to be get the job done and they vary even more wildly than the US regions.
2. Most people (if not all) are guessing at why something works or does not work. We simply have no idea why certain things work, and even varying the variables either at the field or in subsequent designs does not necessarily ensure that a whole NEW set of variables has not crept in to skew the results (like maybe that new plane is straighter than the old one by a fraction). We really do not have the resources to do much more than try trial and error design, and the data set is so small (how many ships does one person really build?) that we can "guess" at design elements and their effects, but unless the change is truly DRASTIC the effects are "in the noise" as Brett says.
3. Truly, these designs have changed so little in 50 years, top fliers could compete with very old designs and still do about the same. This is true even though many older designs had no "modern design" elements at all.
4. Personal preference creeps into every single one of these discussions. What I mean is that, even if I flew the Nats winner's airplane I might not like it. This would ultimately be due to neutral setting, control rate, CG, handle type, engine run type, airplane speed, etc which would have more to do with whether someone would like the experience rather than the airplane itself. People get used to a certain "look" or "feel" of a pattern, and that is what they want to see. Everything else is not as good, even if another design (with a particular pilot) flies the pattern more correctly.
I think the main disadvantage to the inline setup is the asymmetry built into the rear pushrod. I think that Tom Morris published a work about how as the angle of the rear pushrod is increased relative the wing and stab, more asymmetry is built into the controls. I will just have to say that this makes sense, even though I have never actually tried to prove it to myself (Tom has little demo models built). Someone might be able to comment here, as I do not remember the specifics that Tom discussed.
Topic: Stabs and the "AVANTI" for Ted. (Read 31324 times)