Ultimate thrust angle question
 

Hi

Ive had a few more days at the field with my New Ultimate and I have some questions. as a rule i like a tad of up trim in a plane but this years Ultimate seems to need a bit of down trim to stay level. I dont have an incedance meter and i just built the kit like i do any ARF and she does fly very well. I allways have a bit of wind so good flight trimming has been a problem. Well the other day we had a calm one and the amount of down trim i needed was more than I think we should have the counter balance was almost above the stab when i landed I shook my head. I spend most my flights hovering around with my jaw open going OMG look what this thing is doing why would anyone fly this thing streight and level?

So I have a few days where we wont be flying the rain has come. I want to see if i can make some adjustments to this thing before I go out and burn up my lifes savings in fuel flying it. Right now it has a Evolution 58 and a 24-10 prop i was considering the prop thrust angles as a place to start. Any Ideas? next was a reafermation of the incedance of the top wing in inches so I can use a tape measre I know its a bit ctude but we aint flying a space shuttle. other than this Im open to any and all Ideas. thank you all for your time

RE: Ultimate thrust angle question
 

The upper wing TE shoule be 1/4" higher than the LE. Just measure between the top and bottom wings, the rear should be 1/4" farther apart than the front.

TF

RE: Ultimate thrust angle question
 

Im close to that I will check that again after the last little repair things may have changed I didnt know if the thrust could be checked as well I know thats built in. But sometimes a little tweaking can be a good thing

RE: Ultimate thrust angle question
 

Thrust can be checed as well but it's unlikely to be off. You can try changing it but that can be a pain. Whatever you do do a little at a time.

TF

RE: Ultimate thrust angle question
 

Balance will also have an influence on trim quantities. Start at 6-1/2 " aft of the top wing point and move bach to 6-3/4" aft and see how that works for you. If the wing incidences are close, and the c/g falls within that range you may want to experiment with up and down thrust a little. I wouldn't go more than two degrees either direction in the attempt to find what you seek.

Bear in mind that the 24" prop you are running due to a larger engine is having an impact of it's own that you will have to factor into the trim equation.

RE: Ultimate thrust angle question
 

the prop size was on my mind. I have it at 6 and 1/2 back now maybe just a touch farther back. I cant see moving it any further back till i know why she is taking this much down trim I still have to recheck the top wing incedance may get to that today.