quote:

ORIGINAL: fun_fly_3D

it is a profile plane. They will do this inherintly (SP??). This is most of the time caused by having the cg too far aft. I understand that the cg is right on according to the manufacturer, but you must also realize what type of plane it is. most profiles are meant to be hovered and harriered and the setup (including cg) is recommended likewise. if you want to check what is causing it, fly a downline so the wings are perpendicular to you (ie, you see the profile of the plane and one wing tip as if you were flying left to right (or right to left) when you pushed down. Make sure this is on a relatively calm day so wind won't be a big factor. anyway, do this up high. throttle should be at idle. after you get it flying straight towards the ground, push throttle foward and observe if the nose tries to pull out harder. if this is the case, it is incidence or engine up thrust. if it still flies true, it is cg. another way to tell is to roll inverted and push to a 45 upline at half throttle. it should require a small amount of down elevator to keep it there. if the tail tries to fall out, you are too tail heavy. if it tries to dive hard, try adjusting the throttle stick to see if throttle make a difference in how hard it pulls out. if it does, then my bet is incidence. let me know if you are confused and I can explain it better. PM me if you want and I will give you my phone number and you can call and I can talk you through it.

Brian

quote:

ORIGINAL: ERJ_Pilot

quote:

ORIGINAL: fun_fly_3D

it is a profile plane. They will do this inherintly (SP??). This is most of the time caused by having the cg too far aft. I understand that the cg is right on according to the manufacturer, but you must also realize what type of plane it is. most profiles are meant to be hovered and harriered and the setup (including cg) is recommended likewise. if you want to check what is causing it, fly a downline so the wings are perpendicular to you (ie, you see the profile of the plane and one wing tip as if you were flying left to right (or right to left) when you pushed down. Make sure this is on a relatively calm day so wind won't be a big factor. anyway, do this up high. throttle should be at idle. after you get it flying straight towards the ground, push throttle foward and observe if the nose tries to pull out harder. if this is the case, it is incidence or engine up thrust. if it still flies true, it is cg. another way to tell is to roll inverted and push to a 45 upline at half throttle. it should require a small amount of down elevator to keep it there. if the tail tries to fall out, you are too tail heavy. if it tries to dive hard, try adjusting the throttle stick to see if throttle make a difference in how hard it pulls out. if it does, then my bet is incidence. let me know if you are confused and I can explain it better. PM me if you want and I will give you my phone number and you can call and I can talk you through it.

Brian

I understand the first part, that makes sense to me and I will test this next time I am flying it. The second part however, you kind of lost me. Fly an inverted 45 degree climb?

If however, that profile planes are supposed to fly like that, then thats fine by me. It was still stable, and once I had it trimmed out it flew straight. I did have a problem with it needing more/less aileron trim the faster/slower I flew (very negligible amount though, one or two clicks of trim), but I believe that is due to the fact that I neglected to balance the aircraft with respect to the roll axis.

BTW it is a Morris Hobbies Pen Knife.

ya. pull up to a 45 upline. roll inverted. what this tests is the planes tendencies. If the tail is flying low in straight and level upright flight due to tail heaviness, the tail should still fly low inverted. If however it is caused by incidence in the tail, it should pull towards the ground when inverted. (i.e. the tail is forced down in upright flight and up in inverted flight.) this will vary with throttle because as more air rushes over the surface, the more or less lift it has. Like I said, if you want me to explain ti in depth, send me a pm and well talk on the phone. I was sponsored for a while, so id be glad to help.

Brian