ORIGINAL: flyncajun
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
Bryan
hebertcompetitiondesigns.com
Bryan,
Since the OP never returned to the thread with any feed back and you are discussing trimming approaches; would you mind reviewing my advice of post #4?
ORIGINAL: Lnewqban
ORIGINAL OP's question: ytell
I'm a little confused about some aspects of trimming an aerobatic model.
If your model is perfectly trimmed, so they say, you will be able to fly a perfect hands free lines on all basic directions: level, 45 deg up and down, verticals up and downs. Now how can this be true if each if for each type of line the wing is significantly loaded differently? e.g for level flight the wing creates lift which is exactly the weight of the plane anf in 45 deg. clibe lift and drag are completely diferent from a level flight?
If the plane pulls to the belly on vertical line, so they say, increase your wing incidence.
How can this be true if the elevator trim position is not changed? as fa as I understand, the elevator will keep the wing in the same AOA regardless of wing incidence change (assuming constant speed is maintained)
Yoav
The wing is what flies, and the prop helps it; the rest of the airplane just follows.
Hence, increase your wing incidence = decrease the incidence of the rest of the airplane = same wing AOA
If the plane pulls to the belly on vertical line => decrease the incidence of the rest of the airplane = stab pushes ''down'' more and increases a nose pitch ''up'' that works against the ''pull to the belly'' tendency