RV-8/8A order form questions

I turned in my last report at Test Pilot School on Tuesday and shortly will be moving on to my next goal in life (build an aircraft). So... today I printed out the order form for the RV-8/8A and looked over it. I have a few questions and maybe some of you expert guys can help a newbie out.

1) I was going to order the preview plan set from Vans then I saw this Builder's Books. Which one would be the most informative out of these 2 products. Do I need both?

2) I know this is builder prefference however, what are the pros and cons on installing an electric elevator trim to the empennage kit? Will there be limitations later on if I decide to install an autopilot (I don't really know how the trim system inter-acts with control cables)?

3) I did not see an 8 or 8A option for the wings. Does the wing fit on both models?

4) would building the wing be the next logical step after the tail kit?

Tank you for any help or guidance with this matter.

From looking at the builder's book site, that sounds like exactly the same thing as the preview set - the set from van's has the full manual, all plans (shrunk), etc.

The wings are the same between the -8 and -8a. You do not have to decide which you want until time to order the fuse.

Most people do the wings after the tail; not having touched the fuse yet, all I can say is the wing seems like a good way to go.

As far as the trim, that is a personal preference sort of thing. I think (but am not sure) that if you want a 2 axis AP you may need the electric trim servo in the tail.

hope that helps! Good luck.

Thomas
-8 ailerons

Not that I'm an expert on these kits or anything, but I'll take a stab:

1) You have to order the plans.. either as a preview or with your first kit order. It looks like you can order the official plans from buildersbooks.com and they don't seem any different than what you get from Van's. So I don't think it matters, you just have to buy it at some point. (Might as well get it from Van's, since you are ordering from them now anyways, right?)

2) I'm not doing elevator trim just because I'm use to manual trim and I don't want to worry about the extra complexity of that setup. I also asked the autopilot question and was told that they are completely separate so you wouldn't be limiting your AP options later.

3) The wings are universal as far as I understand.

4) The wings are what most people do next but I think you can do it in any order. Are you going to order the QB of any of these? If so, you need to figure that out before you do your order as they may need to keep some parts back to match with whatever they are making as a QB.

Hope that helps

ccrawford said:

4) The wings are what most people do next but I think you can do it in any order. Are you going to order the QB of any of these? If so, you need to figure that out before you do your order as they may need to keep some parts back to match with whatever they are making as a QB.

Hope that helps

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Thanks for the quick response to you both. I would like to buy the QB but an extra 8k could go into something else. right now the plan is to build the entire A/C.

If you see Sniffer on your way out the door tell em EASL sends his regards.



Luis

One note about the build order- you have to at least order the wings, before you can build the fuselage, because the center section of the fuselage is included in the wing kit. The reason is that the center section bulkheads are match drilled with the wing spars.

electric trim

(I don't really know how the trim system inter-acts with control cables)?

Click to expand...

The rudder uses cables, but the elevators and ailerons use push tubes. The trim tab is on the left elevator and, with electric trim, the servo is mounted inside the elevator itself. A five-wire bundle runs from the cockpit to the servo and there is no interaction with the control system. If you do order the preview plans they include 11x17 versions of all full size plans and you'll be able to see how it all comes together. Hope this helps.

2) I know this is builder prefference however, what are the pros and cons on installing an electric elevator trim to the empennage kit? Will there be limitations later on if I decide to install an autopilot (I don't really know how the trim system inter-acts with control cables)?


This is a completely personal preference thing. The trim does not interact with the autopilot at all. There are 'trim sensing' altitude hold units that will annunciate to you if the airplane is out of trim and will let you adjust the trim accordingly. The trim sensing works by measuring the amount of force required in the servo to hold the elevator in the proper position to maintain altitude...so it doesn't interect with the trim at all. It just measures the force to hold the elevator in place and then let's you know when the force goes to nil (meaning the plane is in trim).

Since (per the plans) the trim servo and cable are attached to a mounting plate on the bottom of the elevator, it seems that it would be a trivial change on an unfinished airframe. If the top skins are on the fuse, I would guess that running the manual elevator trim cable would not be too much fun.