RV-7 vs RV-8 aileron response

[sf3543]

I have flown all three. Owned a -6 for years and over 155 hrs on the -8 and a few hrs in the -7.
When I first started flying the RV8, I noticed that it was heavier in the stick than the RV6 and RV7.
I think that the RV6 was lightest in control response across the board, the RV7 next and then the RV8. (Although different power and loading surely has some impact on this.)
In roll, I don't think it is that much different, but the RV6 seems to be lightest.
In pitch, the RV6 is definitely lighter on stick forces; however, as someone opined earlier, as the CG moves back on the RV8, they do get lighter.
In my opinion, the RV6 was the nicest handling, with the RV7 a very close second. The RV8 is dependent on how it is loaded....with a forward CG you get a heavier stick. On the RV6, the passenger and baggage weight stays closer to the spar, due to side by side seating, which works to keep it more nimble. (My opinion)
I also found the RV8 to be a little less forgiving in landings and it took a while to be able to consistently land it as well as I did my RV6.
Don't get me wrong, I love my RV8, but there are differences between the different RV types. (Still looking forward to trying on an RV9!)

[terrykohler]

Can someone clear this up for me?
If loading about the axis of rotation is neutral (no heavy wing and/or c.g. which requires elevator input) and speed is constant, aren't stick forces primarily a function of:
1. Control surface area and center of effort on outboard end.
2. Length of control stick and hand position on the other?

Isn't roll rate measured at full control deflection regardless of stick force?
I would think it would be more a function of wingspan and control effectiveness.

Any aeronautical engineers or test pilots out there with a non-subjective answer?
Thanks,
Terry

[rvbuilder2002]

Originally Posted by terrykohler

Can someone clear this up for me?
If loading about the axis of rotation is neutral (no heavy wing and/or c.g. which requires elevator input) and speed is constant, aren't stick forces primarily a function of:
1. Control surface area and center of effort on outboard end.
2. Length of control stick and hand position on the other?

These two things cause some of the difference. I believe there are also others.

The ailerons on an RV-6 are smaller in span than they are for a 7 or 8.
When the 6 was orig. designed, the wing span remained the same as a 4, but the wing panels were slightly smaller because of the wider fuselage between them. The flaps were made (mostly) the same size as those on the 4 so the panel size difference was accounted for in a change to the aileron.
The RV-8 (and then 7) got a wing panel that is basically the same size as the RV-4. I think the surface area accounts for a lot of the stick force difference but not all of it.
The RV-7 and 8 also have totally different style aileron bell cranks which I believe accounts for a slight change in stick force. Add in stick length differences and other variations of the control system and you get a noticeable difference between the models.


Between the RV-6,7, and 8, my favorite also is the 6.

[svanarts]

Originally Posted by pierre smith

Billy Waters had a 6 and now flies an 8. He has often told me that the 6 was a much better flier. BTW, I didn't shorten my stick any. The Van's pistol grips are at the same height as the original stick. Experienced RV fliers will, to a man, tell you that the -4 is the best flier of the bunch.

Thanks, Scott,

Yes.
Absolutely.
And not just because I fly one.

I think it's a "grass is greener" thing. Two other EAA chapter members each have an RV-8 and an RV-6A. Both their ailerons seem lighter to me.

[Mel]

Originally Posted by pierre smith

Billy Waters had a 6 and now flies an 8. He has often told me that the 6 was a much better flier. BTW, I didn't shorten my stick any. The Van's pistol grips are at the same height as the original stick. Experienced RV fliers will, to a man, tell you that the -4 is the best flier of the bunch.

Thanks, Scott,

Sounds like these "experienced RV fliers" haven't flown the -3. Everyone I know of that has flown the -3 thinks it is the best.

[rvpilot]

Everyone I know of that has flown the -3 thinks it is the best.

Heard the same thing! Helping a friend complete a -3, looking forward to flying it!

[Stephen Lindberg]

Originally Posted by Mel

Sounds like these "experienced RV fliers" haven't flown the -3. Everyone I know of that has flown the -3 thinks it is the best.

The original 3 had a fuselage tank; the 3B has two 15 gallon wing tanks. Does anyone have any experience with the two different configurations? I wonder if the wing fuel noticeably changes roll characteristics.

[nucleus]

My builder assist man Noel Simmons says the 6 is more nimble than the 7. Hooray for the 6!. He has built like 20 RV's.

Hans

[Mel]

Originally Posted by Stephen Lindberg

The original 3 had a fuselage tank; the 3B has two 15 gallon wing tanks. Does anyone have any experience with the two different configurations? I wonder if the wing fuel noticeably changes roll characteristics.

All of the -3s I've flown have had the wing tanks, so I can't compare the fuselage tank. But every one I've flown has performed better than any other RV I've flown. BTW, many of the straight -3s and -3As have been converted to wing tanks. I won't fly a -3 unless it's had at least the -A mod.

[Kahuna]

I have flown them all, except the 12. My 2 cents below.

The 3 is NOT better in roll. In fact its as bad as the 8. What the 3 has is super tight pitch capibility, loops done in 300'. Its light and fun. Roll rate is high, but roll force is also high. I was not particularly pleased with the 3 in roll, but man will it loop like right now. If your doing a little ACM with your buds, the 3 cant be beat. It will out turn, climb and roll any of the others with a 160 sench FP. Its pretty cool. But would not be my first choice for overall best feel.

The 6 has the best roll feel in force. But not the best rate. I have a couple hours in a 6 and 8. The 6 handles better than the 8 in all aspects of handling capibility. But the center axis of the 8 is more pleasurable in handling.

The 4 is best best all around for feel in force and rate in pitch and roll. It is my choice for "handling".

The 9.. Well its ok for what it is. Still cant for the life of me figure out why people are byuilding these, but they are.

The 10 is fun, but its of course outside the bounds of these handling discussions. Vis is good, room is great. Its going to really smack this market silly up side the head.

The 12.. Your not getting me in that ugly looking thing.

Done with my 2 cents.
Best