a70eliminator

I built a Smith miniplane k&b 61 with header and tuned pipe, maiden flight yesterday almost crashed it upon takeoff had to apply full right aileron and hold plane still banking so quickly applied full right rudder and finally with full right aileron and rudder was able to get up and away where I had time to trim full right, it was somewhat a handfull to say the least, I brought it in and safely landed, I'm looking at why the ailerons needed full right trim to be off so far for the plane to fly straight, could lateral balance have that much effect? She is left heavy due to pipe and header but didn't think it would be that much of an issue? Never had a plane trim that far off, all the control surfaces were dead center to start, now ailerons are really far off center to the right,

600Bob

Twists in the wings or tail? Check the lateral balance to see that it isn't more than just a muffler.

AMA 74894

My Feedback: (1)

highly UNlikely lateral balance would be THAT far off... (but of course check and fix)
I'm with 600Bob, twist / warp in the fuselage (OR wing) misalignment of the wing mounting..
asymmetry somewhere... (one wing panel longer than the other)
any chance the firewall has LEFT thrust built in? Engine torque will cause a roll to the left typically,
(which is why RIGHT thrust is sometimes used) .. if for some reason the thrust is offset to the left by accident it could cause these symptoms.
maybe one elevator half travels while the other half does not?

a70eliminator

Thanks I'm going to look closely at all these those things tonight, I'll try getting some photos up,

JohnBuckner

My Feedback: (1)

Almost a certain bet that the right side (or cell) is washed in, the left side is washed out or any combination of that. You know what works for me is the good old eyeball method of checking works best.

Just prop the airplane up more or less level on a table with something under the tailwheel then stand back directly off the ends of the wings at least ten feet, squat or sit so that your eyeball is level with height of the airplane. Now just look for any obvious washout or washin first on one side then have someone rotate the airplane and with you eye in the same orientation and look a difference in the opposite side or bay.

If there is a problem this will be pretty obvious using this method. Also while some biplanes use different incidence for upper and lower wings it should not more than just a few degrees. If you make a correction always better to wash out a panel or bay rather than add wash in. In fact wash in should never be added beyond just flat with no twist.

John

a70eliminator

Can you take a look at the pics see something I may be missing, All I see is the stab my be ever so slightly tilted left. Measure from prop tips back to vertical fin and the thrust line is dead center. I left the ailerons in the last position of trim when i got it under control and landed, you can see how much they are deflected, the left slightly more than the right. The K&B 61 powered this plane like a rocket and it's sure going to be a fun plane if I can get it to fly straight. by the way the wing struts aren't on in the pics but they are a perfect fit.

JohnBuckner

My Feedback: (1)

None of the pictures are all that useful there need be only two pictures and the one that you got in the area is of no use you need to be looking straight at the the wing tips the camera level is two low in the the only picture from the side You need one from the left side of the airplane and you need one from the rigtht side from the same camera position. Also you need to prop up the tailwheel to a roughly level fuselage position.

What ever slight horizontal stabilizer tilt may be present there is not going to be causing a severe roll. That may induce some odd coupling in some advanced aerobatics but not the severe roll you describe.

jester_s1

In the second pic from the left on the bottom, it looks like the top wing is significantly twisted. The sideways pic on the top left also looks that way since more of the checkerboard shows on one side than the other. That would cause the problem you are describing. You should be able to fix it by twisting the wing while hitting it with a heat gun. It really helps to have an extra set of hands for that.

Lateral balance usually shows up under significant G loading, such as pulling out of a dive. You'll see the plane drop a wing on the heavy side when you pull the elevator.

speedracerntrixie

My Feedback: (29)

The only real way to know what is going on is to measure everything out. Block up the tail while on a flat table and level out one wing tip. Then measure out the remaining 3. Good news is that with iron on coverings you can twist and re tighten to fix. I can't tell you how many times I had introduced a twist into a wing while covering. Once you have the wings straight, make adjustments to the struts. Once everything is set correctly the wings and struts become a box structure that will keep the "set"

You may also want to consider putting 2 or 3 degrees of right thrust into it as well.

flycatch

My Feedback: (26)

I reviewed the pictures provided and it is obvious that the top wing panel and horizontal empennage are not square to the bottom wing. This condition will roll the airframe to the left. I had a similar condition on a H9 ARF Taylorcraft with the horizontal empennage. The fix is easy by shimming both the wing and stab.