Aileron trim

[HeliCooper]

Just wanted to get everyone's opinion on installing aileron trim. Is it worth the expense for an airplane that will have an autopilot?

[Scott Hersha]

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.

[BobTurner]

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.

[vanduyn]

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.

[Ironflight]

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.

[rvbuilder2002]

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.

[BobTurner]

Originally Posted by rvbuilder2002

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.

[rvbuilder2002]

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.

[GigAir]

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?

[rvbuilder2002]

It should be relatively easy to install as a retrofit.