Forget about thrust and incidence angle. Any airplane in level flight has a specific speed and angle of attack. An increase in speed requires a lower angle of attack and a slower speed requires an increase in the angle of attack to maintain a constant level of flight. An increase in throttle at the same angel of attack for level flight will result in more lift and the climb you are experencing. To maintain level flight as you increase speed you must apply forward stick pressure(down elevator) and conversely you must apply back stick pressure(up elevator). If you have a programmable radio, you can program a throttle increase with a corresponding down elevator and thus level flight. This will require some experimentation as to how much elevator is needed. This is a rather simple explanation of a rather complex subject, but if you want a detailed explanation read Chapter 1 of Wolfgang Langewiesche's book Stick and Rudder.

Just put one up today. With a Saito 45 in it turning a 10x6 at 10,500. Balanced perfect with that engine with receiver and battery tucked behind fuel tank. Didn't have to touch the trims at all from initial settings! When throttled down to half it dropped altitude slowly. Put in a little up trim and it held level flight at the half throttle setting. It will fly upside down too. No sluggish reponse time and waiting for it to do it's thing. Lands like a -----cat. I would strongly recommend this for a trainer. And the constructional design gives it a lot more strength than a stanard balsa plane. Greeeeeeeaaaaaaaat plane. Need any more info email me at [email protected] Jim

The definition of Angle of attack is THE ACUTE ANGLE BETWEEN THE CORD ANGLE OF AN AIRFOIL AND RELATIVE WIND. A flat bottom wing will normally have increased lift with increased speed given a constant angle of attack(the faster you go the higher you climb). If the C.G. is correct and the wing and horizontal stab are in harmony with one another then there is no reason to fight the trim with every throttle change when one could add down thrust. I dislike flying a trainer with a flat bottom wing when a semi or fully semetrical trainer will fly just as forgiving with the proper dihedral and wing load. Also doesn't have the trim issues associated with the flat bottom. Hobbico makes a great example of a trainer with a fully (or semi) semetrical wing which flies excellent and can be flown inverted as your skill progresses without adding full down elevator. Use an incedence meter and then try a few things that you have read here. Let us know what you finally decide worked for you. Every full scale pilot knows about the elevator controlling forward speed and the throttle controlling pitch. If you have any doubt of this try climbing and then chop the throttle. Bet the nose comes down. As modellers we know this as we set up a glide slope for landing our model and control the glide path with the throttle while keeping the elevator in a fixed position. Nothing wrong with trimming the plane to fly like you want it to fly though. Play around with it and learn a lot!!! Use the knowledge on your next plane. Remember when you use the Pattern trim chart that pattern planes are not flat bottom airfoil and it will show that too much down thrust will cause the plane to balloon when the throttle is chopped because of the up elevator trim used to counter it. Your flat bottow wing doesn't need the up trim to counter the down thrust because it generates the counter force itself and as speed bleeds off the lift decreases all by itself. My 2.5 cents worth.

J%$#s f$#%&n C%@#$t..... ITS NORMAL !!!!!
I'm switchen to choppers

Here is a Little cheater method I have used to counter Engine thrust and high speed climb, If you have a programable radio set upa mix between the throttle and elevator so you get a slight down elevator as you increase throttle, the same will work for engine torque as well, The will be a slight delay for the high speed mix untill the airplane comes up to speed.

When using down thrust or the mixer to counter a high speed climb be ready for a fairly sharp climb When you chop the throttle, the airplane will still be at speed .

If you want to know more about the use of wing angles and down thrust ask the Free Flight Guys, They use it exclusively to control climb and glide.

Hey Outcast---Choppers change altitude with throttle changes too---LOL

Sorry to disappoint so many of you, but the elevator is not the up and down control, it is the speed controller. Not just at MCA or during landing but in all flight. I fly full-size, all sorts from 1930s biplanes to military jets, and the rule of elevator to control speed is an absolute in all aircraft at all speeds in all flight phases. Power is the height controller. Of course you can make changes to height by pulling back on the stick if you have enough surplus speed but all you do is swap speed for height and the aircraft's energy does not change. I suggest that you hire a Tiger Moth and when it is trimmed in the cruise, try pulling gently back on the elevator. For about 2 seconds you gain a few feet, then the speed drops drastically and you start losing height. The more you pull back, the faster you go down. Even in a jet fighter the speed responds instantly to elevator, they just tend to have so much speed above stall in normal cruise that they it takes some time for the swap of all surplus speed into height to happen.

All aircraft from the tiniest free flight model to a B747 gain height as power is increased and lose height as power is decreased. It is written into the laws of nature. An object has an energy, it is only we humans that separate it into kinetic and potential energies for the sake of calculations. To increase height but keep the same speed, an object must have its energy increased and the only way to do this is to add power. Using ele will just leave the plane higher but slower and it must now descend back down to regain the same speed it started with!

What we seek to do is avoid the violent pitch change that some models have and downthrust helps this, but beyond that it is vital that all new beginners learn that to go up they increase power and to go down the reduce power, with the elevator being used to set the plane's attitude and hence its speed.

Harry

Maybe someone has already posted this website but there is no harm in posting it again.

http://www.monmouth.com/~jsd/how/

Interesting thread.


Steven

Hey Hots, I thought helis went up with collective! OK thats it, I'm going fishing.

Most everyone here has a good point.
I fly full size also and I know that when you have the power to weight ratio as we do with R/C planes, you can throw the full size aerodynamics book away.
Only time I find this information helpful is on take-off and landing.

(scribbling on notepad) Ummmmmmm....what was the question again?