[iwannarv]

My dad was talking to a guy who had his RV8 for sale, and asked for the phone number of the original builder. While talking to the builder of the -8, he mention that if my dad has never flown an -8 before, that there is a time when flying any -8 there is one certain spot that you have no elevator control. I am not sure if this was in a langing config., but at a certain control input having no elevator control???

 

[Ironflight]

Well, that's a new one to me....but I've only got a bit more than 300 hours on my -8, so I am sure it still has things it will teach me.

Paul

 

[chrispratt]

RV-8 dead spot

I seem to recall that some of the early -8 builders mentioned a point in landing configuration where the elevators went a little dead or at least changed feel noticeably. Definitely something that got their attention. Hopefully, a few will read this and enlighten us.

I haven't heard anyone mention it in a long time. I've been flying mine for 130 hours and no signs of any bad manners. Perhaps the design was changed to address the issue.

Chris

 

[iwannarv]

I seem to recall that some of the early -8 builders mentioned a point in landing configuration where the elevators went a little dead or at least changed feel noticeably. Definitely something that got their attention. Hopefully, a few will read this and enlighten us.
Chris

Chris-

Sounds like that is what he was talking about. This particular RV is a '99 model, if that helps any.

 

[rvpilot]

Dead Spot??

Could it be someone might have got a little slow in their flare, with not quite enough power? I think all RV's like to drop out of the sky in this siutuation! I can see where it might seem as though the elevator quit working to the uninitiated! Gotta have quick hands in this situation!!

 

[flyeyes]

My dad was talking to a guy who had his RV8 for sale, and asked for the phone number of the original builder. While talking to the builder of the -8, he mention that if my dad has never flown an -8 before, that there is a time when flying any -8 there is one certain spot that you have no elevator control. I am not sure if this was in a langing config., but at a certain control input having no elevator control???

Many -8s tend toward forward C of G, especially with big engines and/or metal constant-speed props. This was an intentional design choice, as many -4s tend towards aft C of G, which limits their back seat loads.

I suspect that this guy was referring to the fact that some -8s are difficult to three-point when solo, seeming to run out of up elevator.

My RV-8 is hard to three-point when solo, but I can put 260# in the back seat. I think it's a fair trade-off. I do occasionally throw some ballast in the aft baggage when I'm doing a lot of solo flying, because it's a little nicer to land that way.

James Freeman

 

[Brian Denk]

I fly a '99

My RV8 has no unusual elevator behaviors whatsoever. Yes, it goes soft when the wing stalls, but that's your cue to UNLOAD. Simple as that.
The RV8 with metal prop flown solo is nose heavy and can get close to running out of nose up trim for three pointers. With bubba on board, no problem. I fly with about thirty pounds of tools/survival stuff on the hat shelf when solo and it helps a lot. I move it to the forward hold with a pax on board.

 

[martin333]

RV8 tail shudder/flutter

I seem to recall that some of the early -8 builders mentioned a point in landing configuration where the elevators went a little dead or at least changed feel noticeably. Definitely something that got their attention. Hopefully, a few will read this and enlighten us.

I haven't heard anyone mention it in a long time. I've been flying mine for 130 hours and no signs of any bad manners. Perhaps the design was changed to address the issue.

Chris

Listers,
I have ser. # 2 RV8. I finished it in 1999 and now have 1400 hours.
When I first flew it, I experienced a similar phenomen, usually when making a full stall landing. I would experience a short quick flutter like feel in the elevator . It was never bad, but always interesting.
As I flew the airplane more, I began to make all of the little mods etc. that we all do. I was dissatisfied with the landing gear fairings suggested by Van.
So I began to experiment with different shapes on the upper gear leg to fuselage fairings. I made one with a considerable "lead" on the front and rear of the fairing. Results! The shudder disappeared and I increased my speed a few knots. Note: I originally had 76" Hartzell & a IO360 engine. I now have a 74" Aero Composites prop (15 lbs lighter and 16mph faster) with a new Barrette IO390AlB6 engine. Above speed was obtained with both the IO360 and IO390 engine

Dick Martin
RV8 N233M
the fast one

 

[gmcjetpilot]

Dead Band

"Dead Spot" or technical term "Dead Band", means a thick boundary layer builds and makes a control surface lack feel and become ineffective in a small range of movement when in trail. Little movements give little or no feed back or effectively. This is most common with rudders. The fix is a trailing edge dam installed on the trailing edge; a small edge or lip dams up the boundary layer and gives the control surface effectively and feel with little drag penalty.

Now the RV-8? I doubt it has a dead band. However it could be slop in the control linkage which would be hazardous.

The other issue common to all RV's is BAD trailing edge radius. It must be perfectly tangent and not bulge before the trailing edge. As you know the instructions are clear about this. If you do have a poor or large trailing edge radius you can float up or float down from the air leaving the trailing edge improperly formed. With the aileron this creates roll. On the elevator you get odd control response feel. Make sure the elevator is per plans.

 

[cdwambolt]

Maybe this is for a new thread, but is there any advantage to some of the other construction methods for that trailing edge. The double flush edge like is on the 9, or the sherman tank method on the F1 rockets. BTW can one of you rocket surgeons explain that to me (the double bend with a bunch of 470 rivets)?

 

[mannanj]

RV-8 Tail Shake

I experienced this phenomina in my-8 on the back side of a loop last Sat. w/ a Bubba in the Back Seat. Probably shouldn't have happened in that situation, but it did.

I agree with Dick Martin---There's something happening in the gear leg/wing intersection area causing this. I will concede that it may be an elevator trailing edge problem, but I'm going to try Dick's Landing Gear Upper Fairing mod to see if it goes away. I took soome pics of his fairings at OSH. and am trying to duplicate them. If I gain a few knots, so much the better. (Over the years I've discovered all aviation speed claims are lies to begin with. Sorry Dick, if yours works it will be the first one I've run across!!!!!)

Will post results if it ever warms up enough to try to fiberglass!

Mannan Thomson
RV-8 N161RL (No. One Girl)
Not nearly as fast as Dick's!