EXTREMELY sensitive ailerons

[rv7guy2]

Now that I have an hour in my RV-7 I have a worry about the EXTREMELY sensitive ailerons. They are so sensitive that I think they are dangerous. It's like balancing a ball on the point of a needle. Just breathe on the stick and the plan "snaps" either left or right. I can steady it , with great effort, and fly straight and level and gently turn but it's way more sensitive than the RV-7 of the check pilot who is helping me. He is quite conerned about the snatchy, snappy feel of the ailerons. Conversely the elevators and rudder feel very much like my check pilot's RV-7.
One person has suggested squeezing down the trailing edges both airlerons as you would for a heavy wing saying that helped his plane which had a similar problem.
What is your opinion?

Dave

 

[Kahuna]

Before getting too excited, Id recommend an experienced RV pilot take a look. Not one that has one plane, butone that has flown many.

If he determines there is a problem, then squeezing the ailerons may help. A rounded edge lightens the feel, sharper edge gets it heavier. Its all a trade off. Rounded is better for light feel on roll, but has increased drag. Sharp edge=less drag and heavier feel.

I taped a piece of balsa strip to my ailerons to duplicate whats done on some of the higher performance acro planes like SP's and Suk's, it was amazing how light the roll really was. Took a few measuable knots off the top though. Fun to try as an experiement.

Anyway, my vote is do nothing until an experienced RV pilot gets a hold of it for you. One mans snappy is another mans sluggish based on experience.

Best,

 

[rocketbob]

A friend of mine had a similar problem with his new RV-3B. The newer wings (RV-3B,-7,-8) have a different aileron bellcrank design with a 1:1 ratio at the bellcrank. One of my friends who has over 3000 hours in RVs did the test flying, and recommended modifying the bellcrank by making up a new arm on the bellcrank so that it was longer on the portion that connects to the stick pushrod. Now it handles just like the older RVs in roll, nice and crisp with a bit more stick movement. More leverage at the bellcrank results in more stick travel required to get the same amount of aileron movement.

Something else that will also factor into this is if you shortened the sticks.

If you don't have a wing heavy condition I would leave the aileron trailing edges alone, and would modify the bellcrank. If that doesn't make the roll handling to your liking then you can always order a new bellcrank arm and go back to where you started.

 

[Janekom]

Hi RV7guy2,
I had exactly the same problem on a recently finished RV7A and have discussed it with many as well as with Vans. The background is that I am quite experienced (test pilot rating, etc) and this is my 2nd RV7A project.

The first one was a standard kit where we built the ailerons and bent it (without trying with quite a sharp radius compared to the new one that is a QB.

The solution is to VERY CAREFULLY AND A LITTLE BIT AT A TIME squeeze the trailing edges of both ailerons. Start by only doing about a third of both. Then go and fly and feel the difference. The trick is to do very little as it cannot be reversed.

You will be very happy with the result.

 

[RScott]

Sometimes the best place to start asking questions is the forums and sometimes the best place to start is Vans.

This is a safety issue that could get you on the next flight.

Call Vans first; they designed it. They are the pros.

 

[rvbuilder2002]

Check here http://www.vansairforce.com/community/showpost.php?p=230876&postcount=7
for info in a recent thread.
You should not be just squeezing the trailing edge to get a change, you should first be evaluating the shape of the aileron before adjusting it.

By the way...it is possible to unsqueeze an over squeezed aileron trailing edge (I have done it many times). But you should still progress slowly and carefully, and then only if after evaluating the aileron shape and verifying it needs to be done.
Squeezing (and undoing over squeezed) ailerons is also done to adjust roll trim, but this is on a very small scale compared to make major shape changes.