hello people!!! when my katana is flying on hurrier or it's parachuting, the planes starts to roll bit left and right, left and right. I even don't need to work with ailerons, cause the shaking amplitude is constant and it won't stall on wing. but sometimes it doesn't do this. what is wong? anybody has such a problem?

This is called wing rock. It is a common problem. Doing a harrier you can sometimes increase the AOA(angle of attack) and this will help. You could also try a spoileron mix. On the parachute I only know two cures. Use the spoilerons or do them inverted. Doing them inverted putts the rudder in clean air and will cure the rock most of the time.
One other thing. Sometimes you can use the aile to stop the rock. Don't try and fight the rock all the time. Just wait for one wing to go down and bang it quickly back in place. What I mean is use a quick but heavy input of opposite aile just as the wing goes down. This will stop it most of the time. It will however on a lot of planes start right back up a little at a time.


David

i can't say, that it rocks the wing, I know what is wing rocking. the plane is just shaking and without my input it stabilises It has constant amplitude of shaking angle.

Ok it's not wing rock but it's shaking huh? Balance the prop dude.













Seriously, I think Dave nailed it.

prop is balanced!!! plane is lateraly balanced too!!! but it sometimes happens, sometimes not thats the question, what does it occuar

OK hang on, I think the biggest problem is none of us actually understand what is happening which is causing the problem for you? Please explain the exact problem again and with a little more detail?

I has been answered on rcgr. this is wing rocking, but simulationally wing rocks and regains lift
thanks for answers

This is also affected by wind direction and speed. Try it into the wind and down wind to see when it rocks.