DAN AVILLA

My Feedback: (12)

I had a Boomerang XL with the same problem. You need to check the incidence on both wings . I found one off. I adjusted the pin at the leading edge area. It might be more difficult with your plane. Throttle to aileron mix will not work well because we do not fly at a consent power setting. Dan

wojtek

My Feedback: (73)

It could also be felx in a wing(s) ... if a rib or sheer web is lose especially on the inboard end, this could result possibly ... Im not sure how your wings are constructed. Might want to give it a shot and see if the wings are nice and stiff and resistant to torsion/twisting ..


~V~

saddler

My Feedback: (93)

I had this same problem with a rookie and it took me a long time to find. Are the ailerons live hinged? If so, check the skin where the hinge is. Check to make sure that skin is still securely glued to the trailing edge spar. I found on my rookie that the glue joint between the skin and the balsa rear spar had come apart and caused this exact problem. The faster the airplane went, the worse the roll got.

TimT2000

My Feedback: (1)

Yup, I have seen this.. +1
Tim

kmeyers

You seem a little fixed on the wing. The problem could be in the rudder or elevators halfs as well. Have a few more eyeballs look the plane over. A really good trim takes lots of effort. We always have a fresh set of eyes go over a plane, it only costs a little time.

DelGatoGrande

My Feedback: (23)

usual lateral balance promblem.lift from nose and tail at the same time.add waith to the wing that end high,till you lift it and both stay level
my 2c

turnnburn

My Feedback: (49)

Dan,

I can give two or three reasons why a throttle mix is not a good solution. Its a band aid and it wont even work right. I wouldnt be suprised if the incidence is off from one wing to the other. If it is it will be very hard to fix on this airplane. I will try to check it out later today.

turnnburn

My Feedback: (49)

I am focused on the wing becasue I have checked the tail group and it all appears to be properly lined up and straight. The amount of aileron trim required to fly straight seems to indicate something wing related. Im suspecting there may be more than one problem. I know that there is a small area on the right wing that is very slightly raised and therefore thicker than the left wing. I dont think this is the entire problem however. I have not checked the hinge line skin for delamination and flexing. I dont think this is it but it could be. I plan to try to check wing incidence one wing compared to the other. I hope this isnt off because it will be hard to correct, but I wouldnt be suprised if there is an incidenc issue one wing compared to the other. I plan to check this later today. I am currently re doing the aileron linkage so I can use a shorter servo arm. Im quite sure that this wont be a the solution to all my issues however. At some point if need be I will get some servos with better resolution but I dont think that this is the total solution either. I need to find a good way to check lateral balance as well. Its kind of a hard to do with a 35 lb airplane. I did a crude check of this and it appears that if anything the left wing is the heavy side which would only help my sistuation not hurt it.

Thanks for all the ideas, keep them coming Im learning a lot.

DAN AVILLA

My Feedback: (12)

I know that it is hard to hold the plane for lateral balance. I would weigh each panel first to see how far they are off. You did not say who's kit it was. Maybe some one has had the same problem and has a fix if it is incidence. Good Luck Dan

FalconWings

My Feedback: (57)

I can give you another one - throttle is not proportional to speed in any way. Climb at full throttle, then dive at full throttle. Guarantee you will see a difference in speed. ;-)

turnnburn

My Feedback: (49)

No kidding David. That was among my two or three good reasons why it was not a good idea.

turnnburn

My Feedback: (49)

Latest update. I made new aileron pushrods that allowed me to move one hole in on the servo arm (on the inner most hole now). This allowed me to increase the total servo travel somewhat which means slightly improved resolution. I cut the trim rate in my JR 12x TX from 4 to 2 so the maount of servo travel/er beep or click of trim is finer and more precise. I checked the weight of each wing panel seperatly and they are within an ounce of each other so I dont think that is relevant. I checked the elevators level relative to one another and found a very slight misalignment and corrected it. I checked wing incidence in a rather crude way ( cant find my incidence meter) and they apprear to dead on our very nearly dead on. Eye balled the wings for warps and dont see anything obvious. I found a very small area where the wing trailing edge at the root was cracked and might have been allowing a very small part of the traiking edge to deflect into the slipstream. Repaired all three ares, top and bottom of right wing and bottom only on left wing. Made a mostly unsucessful attempt to get the nose gear door to close the last little bit. No way of knowing if the door is being forced closed in flight by the airstream or stays the same amount open or opens even further due to low pressure area in that location. Probably has little or no effect on the way the plane flies but not sure. It could very well be opening further an further the faster the plane flies and maybe this some how causes a slight rolling moment. I will contine to work to get a completly closed door. Also made sure both ail servos are screwd down tight and made sure jam nuts on both ailero linkages are down tight against the shoulder of each aileron clevis ?

I made one flight today after all of the above. The airplane trim for a constnt airspeed was improved and while not totaly " ON RAILS" dead solid perfect it was improved or so it seemed. However, the faster I fly the more the airplane rolls left ( or was it right?? LOl, Im pretty sure it was right. It seemed like the amount of roll was a little bit less than ot was on tuesday, but still noticeable and undesireable at the very least. If I had had time to make another flight I would have tried with the trim rate set to 1 which would have meant even finer and more precise triming of the aileron servos to see how that would fly. I probably need more precise servos to notice much if any improvment from this. Otherwise I dont know what else to try next. I will probably install some JR digital servs on aileron and see if that helps.

Untill I find the warp or misalingment or whatever it is that is causing the need for left trim to fly straight I suspect my symptoms will cotinue and I will just have to fight it constantly retrim. I suppose I could put a gyro on he aileron chanel and see if I can make that work.

The airplane is the large Jet Legend L-39. Has anybody else had similar issues with this plane and what did you do to fix it ?

flyinfool1

My Feedback: (2)

An ounce difference in the wing weights is a lot.
Put the whole plane together and check the lateral balance.
It may be a 3 man job to do but it is worth the effort.

turnnburn

My Feedback: (49)

The arplane in flight rolls to the right (requires left aileron to fly level), the left wing panel is the heavier of the two panels. If anything the very slightly heavier left wing is helping the situation not making it worse. I dont see the need to do further lateral balancing.

Mariosff

Check the engine and exhaust alingement. Primary effect is yaw but secondary effect is roll

turnnburn

My Feedback: (49)

I will do that but I dont think that is the problem. The roll doesnt occur the second that the engine speeds up it occurs as speed builds and the faster the airplane flys the more it rolls. I still think I need to find out where the plane is warped or out of alignment. Or I may just sell it. I will list it as a very large and expensive prop since it is clearly TWISTED.

turnnburn

My Feedback: (49)

Come on guys that was funny. I thought so anyway.

DAN AVILLA

My Feedback: (12)

I use aileron gyros on my F100 and P80 I do not think it will help. It only reacts to heavy movements like rough air. What you are experiencing is to slow. Heading hold might fix it but would be uncontrollable in the rest of the flight. It would be nice if you can find some one with the same plane that could loan you the wings for a test. What you are trying to cure is tough to find. Good luck Dan

rcjetsaok

My Feedback: (7)

It was !!!! Too much time on your hands Brian !!!!!


Danno

turnnburn

My Feedback: (49)

Thank you. Wanna buy it ? I;ll make you a really good deal on it. Granted it will still be the most expensive prop you ever bought or probably ever will.

Malcolm H

If this plane rolls to the right with increasing airspeed and one wing is heavy, its the left wing. Look at it like this, at zero airspeed there is a left rolling moment caused by the heavy left wing. At a given airspeed you trim for level flight and the ailerons are producing a right roll moment. Now increase the airspeed and the out of balance moment stays the same but the aileron induced moment increases causing a right roll.

Get some automotive stick on wheel balance weights and put a couple of ounces on the right tip, fly and retrim and tell us what happens.

Malcolm

turnnburn

My Feedback: (49)

Interesting. I think that makes some sense. My left wing is the heavier wing but not by much. Might be worth a try. I'll have to think about this for a day or two. I had decided it was time to try servos with more holding power. Im thinking as the speed is increasing my current servos cant hold the ailerons in the left delfected position that this airplane requires to fly straight and some of the left trim goes away hence the right roll.

FalconWings

My Feedback: (57)

Brian, went flying to TBird this AM, the lake is 40% gone. Did you ever find your old plane? If not, bet you can find it now!

Malcolm H

Trust me at the small amount of deflection you need to counteract the roll it's got nothing to do with holding power. Add the weights!

Malcolm

turnnburn

My Feedback: (49)

did you read the email i sent you ? Read it carefully. My left wing is the heavy wing. But even with a heavy left wing my airplane needs considerable left ail trim. If I add right wing weight wont I need even more left ail trim ?

Im not disputing you, Im just trying to understand.