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Aileron trim

HeliCooper

Well Known Member
Just wanted to get everyone's opinion on installing aileron trim. Is it worth the expense for an airplane that will have an autopilot?
 
I would say it depends on what autopilot you have. I have a G3X dual screen system with two Garmin servos, and the autopilot trims both aileron and pitch trim, in addition to your manually trimming.
 
Very personal choice, your call.

For the record I have a -10, Trio Pro autopilot which is flawless. I regularly practice approaches without the autopilot, as well as fly VFR by hand just for fun. No adjustable aileron or rudder trim, no plans to install them.
 
aileron trim

Aileron trim is a must, unless you are going to fly with the auto pilot always engaged. By the way the only aileron kit available right now is a RV-10 kit which is installed in the left wing in a 10. The 14 has in the right wing, so a little work around is needed. Purchased is last week, we will see how it works.
 
In general, I am a fan of aileron trim (we have it in one form or another in all of our planes), but I do have to say that I have several hours in each of the arv-14 and RV-14A, and can't honestly tell you that I remembered trimming either of them in roll. So I doubt if it is essential - just a matter of personal preference.
 
Having an auto pilot does not negate the need for aileron or pitch trim. An autopilot is designed to fly an airplane that is in trim. Many of them will prompt you when trim needs to be adjusted, and some will now make the adjustment automatically.
 
Having an auto pilot does not negate the need for aileron or pitch trim. An autopilot is designed to fly an airplane that is in trim. Many of them will prompt you when trim needs to be adjusted, and some will now make the adjustment automatically.

This is certainly true in pitch, where the control forces can be large. However, in roll, there are thousands of normally certified and EAB aircraft flying with autopilots, and no aileron trim. IMHO if the autopilot cannot handle roll without a roll-trim, then the airplane is out of rig to begin with and that needs attention.
 
My opinion is different...

A agree that aileron trim is not for correcting inherent trim issues in the airframe that should be fixed, but there are other influences that cause roll trim variation.
Fuel burn being the primary. Because of dihedral, the first fuel burned from an RV fuel tank (other than RV-12) is at the far outboard end. Being far outboard it has the highest roll moment of all the fuel in the tank. The longer the tank (RV-9 or 10) the more influence this has.
Sure, any decent auto pilot can handle it, but they generally perform better and don't have to work as hard, if the the airplane is in trim.
 
Scott: Thank you for expanding my understanding of the need for aileron trim in the RV-14. Page 01-01 of the plan set, shows "aileron trim" as a kit option, but is it available yet? Will it be easily installed in a finished wing?
 
I have the -10 system in my -10, and bought the -10 system for my RV-14. Since I am not using the AHRS mount in the Left wing, I'll probably install it there too, just like the -10.

I can say that Scott is right. You use it for things like fuel imbalance. In the -10, the fuel imbalance is fairly drastic and you notice it easily, especially if a big guy like me is seated on one side and a lightweight on the right. So aileron trim is a must if you want to have a nice hands-free trim without autopilot.
I expect that even though the -14 tanks are shorter, there will still be a tendency to roll, so I am putting the kit in the 14. When I hand fly, I like to be able to go x/c and let go and not have it roll off to one side on me. So having it in trim is important to me. No, I would not say 100% necessary, and you can possibly live without it....I just know that in my airplane, I would not be happy without it.
 
Aileron Trim

It should be relatively easy to install as a retrofit.

Scott,

Isn't the right wing where the aileron trim was supposed to go? The plans on page 19-06 call that 6 pin molex connector the mid-wing installation for the AP Servo, but it has those two wires that go to where the AP roll servo is located, then back to the wing root.

I was thinking the plans were mislabeled and that is where the aileron trim is supposed to go. Also, if the -10 Aileron kit will work with minor fitting, are changes going to made to it to fit the 14, or should we just order the one for the -10. As always, thank you for all of your help.

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They told me last week that yes, the aileron trim will go into the right wing. It has to because of the fact that they used the normal location in the left wing for that AHRS bracket. So the wiring for the aileron trim is in the right wing now. Don't be confused by my saying I was putting it in the left. If you look closely, I said "Since I am not using the AHRS mount in the Left wing, I'll probably install it there too, just like the -10. " So it is just my choice to move it there. Besides that, most of the wiring that I have installed into the wings I will be ripping out because A) I don't want to use molex connectors and B) I'm pulling all my own new wires there that are of my choice of size/color/number of ground wires. I figure if I'm going to rework it to my preference it's easiest in many cases to just snip and yank out what's there. I'm not a big fan of unnecessary connectors anyway, for things that will be fairly permanent.
I'm sure they'll have a trim kit for the RV-14, but like everything else, it will come at a later date, so for me it's easier to just make the -10 version work. If you choose to use the right wing, you will probably (this is just a guess) not have too much fabrication to do, but will not get the connectors that are used to connect it to the wiring. There may be small differences...I'm not sure, but the trim itself is very simple.
 
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