[JoeG]

I was told, after I received my empennage kit, that the rudder shipping with current -7 kits is the same as a -9 rudder. Is that true?

And that the -7 used to ship with an -8 rudder; which I believe has the distinct advantage of utilizing a single folded skin rather than the bonded trailing edge approach I will be facing.

Has anyone considered ordering their -7 kit with a -8 rudder? Would Vans even consider such a request?

Food for thought if you haven't taken the plunge yet...

 

[Highflight]

The previous rudder design of the 7/7A led to questionable spin characteristics so the new (larger) rudder was offered to replace the original for flight safety considerations.

Even though it can be said that earlier old rudder style equipped airplanes weren't exactly falling out of the sky, I don't think you'd want to give up any rudder authority just because you think the older rudder might be easier to build.
There's lots of dicussion you can search for here in VAF that will give you the help you need to make building the new rudder much easier.

If you feel the need to use the old rudder, I'd bet there are a couple hundred out there already built that people have replaced with the new one which could be had for the asking.

 

[BlackRV7]

>>And that the -7 used to ship with an -8 rudder; which I believe has the distinct advantage of utilizing a single folded skin rather than the bonded trailing edge approach I will be facing.<<<

Two different points of view here as to the "advantage" . On the new rudder the stiffeners are much easier to back rivet on than the one piece rudder, no flexing the one piece skin. You do not have to concern yourself as much with the trailing edge of the stiffeners causing stress cracks on the skin due to the radius bend of the one piece skin. There is certainly presentations out there that favor blunt trailing edges of flying surfaces over radius. Add to the fact the trailing edge construction techniques offered by Van's work like charm, at least they did for me. I have seen all sorts of reinventions of the wheel that people came up with to "make it easier" but it was really rediculously straight forward and uncomplicated. After getting my alum. angle (via Lowe's aviation dept.) drilled to match one skin, it took a grand total of maybe an hour to rivet the entire, true as an arrow, trailing edge. My opinion, you get what you pay for, is, follow the plans and move on. There's larger fish to fry than riveting this trailing edge.......plus you get more rudder authority.

Dana Overall
Richmond, KY i39
RV-7, Black Magic

 

[Jamie]

Van's Service Bulletin

For information straight from the horse's mouth on the larger rudder, see here.

The basic concern from Van's was not the inability to recover from a spin. The airplane met all the requirements for spin recovery for a standard category aircraft but not for an aerobatic category aircraft (i.e. took it a little longer to recover from a fully devloped spin). It didn't have to meet either, technically, but Van is anal enough that he wanted it done right so he experimented with the larger -9 rudder on the -7 and found that the larger rudder gave it enough authority that it would recover with fewer rotations. The above-mentioned SB mentions the details. In other words, I don't think I would call the spin characteristics of w/ the -8 rudder "questionable". Van just saw an area where improvement could be made (as he's always looking for) and acted on it.

Now, as to putting the -8 rudder on there? I decided not to do it because that extra turn for recovery may be the difference in a stall-spin accident into the ground and calling yourself a 'dumb-ass' and feeling a little numb for a while. My philosphy is to build it as absolutely as safe as possible. Does the -9 rudder make it safer? I think so (if only marginally). Will I ever need to recover from a stall-spin at low altitude? I hope to never find myself in that situation, but it has happened to lots of very experienced pilots so I don't consider myself immune.

 

[Highflight]

In other words, I don't think I would call the spin characteristics of w/ the -8 rudder "questionable"........

..........I decided not to do it because that extra turn for recovery may be the difference in a stall-spin accident into the ground and calling yourself a 'dumb-ass' and feeling a little numb for a while.

Sounds kind of "questionable" to me

 

[Mel]

In short, use the -9 rudder. If it weren't better, Van wouldn't have changed to it.
Mel...DAR

 

[Jamie]

Sounds kind of "questionable" to me

I see what you're saying Vern and I agree with you. I was just clarifying that there's no question that the aircraft is recoverable from a spin...it's just how many rotations are required to recover. But I agree with your general logic...which is why I built it per Van's recommendation.

 

[Jekyll]

After bending elevator trailing edges and building the split TE rudder for my 7A, I am much happier with the split edge construction method. You get a VERY nice result that is easy and dead-on straight. The bending method is not as easy as it looks - it can be trick. It doesn't take much to over bend the edge or get the radius more pronounced on 1 side or the other. It seems counter intuitive but, you don't have as much control with the bend method or the feel.

I see no reason to accept reduce rudder authority in a spin, especially in something as fleet of foot as an RV-7. I was fortunate to receive my kit with the new rudder but, I would not hesitate to rebuild if I was initially sold the old style.

As always, your results may vary.

Jekyll

 

[JoeG]

I'm going with the kit...

Thanks for the responses. I paid for a -9 rudder and that's what I'm going to build. I built the Vans training kit assembly which uses the -9 approach for the trailing edge. It came out pretty straight and I didn't really know what I was doing! Imagine now, I know a little bit more than nothing and have all you guys here to answer questions. No Problem!

 

[AK180Driver]

I'll trade a completed "9" rudder for a completed "8" for my RV-7. I like the aesthetics better, and I won't be intentionally initiating spins. My rudder is completed except for fiberglass tips/paint/strobe

 

[arffguy]

Last I knew Van still had the "old" folded trailing edge RV-6/8 rudder on it. And it's been a long time since he announced the change to the RV-9 rudder. I don't think he's too concerned............at least with his own employees flying it. I too, think the RV-9 rudder looks too big on the RV-7.

 

[osxuser]

I've got the split one, I'll tell you how it goes when I build it. I think it'll be cake... As for looks, I doubt that an RV could look BAD, so I'm not worried. At worse it might look like a P-51H vs. a P-51D...