does anyone have any ideas on how to keep a trainer with a flat bottom wing from constantly wanting to climb.am flying a used goldberg eagle 2 with a magnun 46 and futuba 6xas 6 channel computer radio.any help wopuld be greatly appreciated. thanks.

First, make sure the CG is properly placed, shift equipment or add weights until that is done. Make sure that the wing is properly seated and fastened down. Was the motor already mounted when you got it. Check it for alignment. You should have about 3 to 5 degrees downthrust (using the elevator as reference) built in and about 3 degrees right thrust. If not, adjust by adding washers under the appropriate mounting bolts. Now, get it up to a safe altitude, set the throttle at about mid range and trim it out for level flight. Now add full power. If it immediately zooms up, you need to increase the down thrust, if it tends to dive as you increase power, reduce the down thrust. Now, it will probably climb as you add power but the transition to climbing from level flight should be gradual as the speed builds up. If you get the thrust line exactly right, it will continue to fly level, just increase speed as the increase in lift due to higher speed in counteracted by the downward component of the thrust.

First, make sure the CG is properly placed, shift equipment or add weights until that is done. Make sure that the wing is properly seated and fastened down. Was the motor already mounted when you got it. Check it for alignment. You should have about 3 to 5 degrees downthrust (using the elevator as reference) built in and about 3 degrees right thrust. If not, adjust by adding washers under the appropriate engine mounting bolts. Now, get it up to a safe altitude, set the throttle at about mid range and trim it out for level flight. Now add full power. If it immediately zooms up, you need to increase the down thrust, if it tends to dive as you increase power, reduce the down thrust. Now, it will probably climb as you add power but the transition to climbing from level flight should be gradual as the speed builds up. If you get the thrust line exactly right, it will continue to fly level as the increased lift due to increased speed is exactly countered by the increase in the downward component of the thrust line. I can usually get all my planes trimmed out so that there is little or no change in altitude with engine thrust as power changes from high idle to full bore.

Otherwise, it's probably just the plane. Climbing is what the airfoil's it's designed for.

The climbing under power and dropping when the power is chopped is a common trait to most high wings. You can fix a lot of it by using Rodney' directions. To really fix it, move up to a low wing tail drager like the 4* series.

I fought the problem as long as I had my trainer. Near the end of it's life, I was flying with a stack of four popscle sticks under the trailing edge of the wing. That helpped a bit, but the problem was still there.

After the fatal crash of the trainer, I made a stick fuselage and put the patched up trainer wings on it along with the tail section from the trainer. I extended the nose by 2" and the tail 1 1/2' from the format of the trainer. I also addes a 1/2" in cord to the elevator. And made it a tail drager. I went through two of these planes before setteling into the 4*60. Each plane flys differntly. Looking back, I think that the modified trainer I had for my second plane would have been an excelent first plane. Still lots of dyhedrial to keep it stable, and the longer movements of the fuselage gave me a very stable plane. It was easier to land than the trainer and overall it just flew beter. Aerodynamic balance is as important as weight balance.

Basicly though until you get ready to solo and move up in planes, you trainer, even with a couple bad habbits, is best. Remember that learning how to get of trouble is as important in keeping out of trouble. Both are good skills to accuire.

could be as simple as down elevator trim????

If you have a digital radio you could always mix your elevator with your throttle. So it has a little more down trim when your throttle is up.

Austin

Typical of a trainer.

Want it to stop climbing? Slow it down.

Want to fly fast? Get rid of your trainer and get an intermediate plane

As MinnFlyer said, it is what trainers do. The tendency to climb when throttled up is part of what makes a trainer a trainer.
When a student panics and hits the throttle the plane climbs. When you get disoriented and get into a dive as the plane build up speed it will automatically pull out of the dive, again because of the climbing tendency.
Add to that the dihedral and high wing combination and the plane wants to fly upright.
Add everything together and it makes an easy plane to learn on. It is designed to do these things.

Trainer are set up with typically 6 degree positive incidence in the wing.

When they are flown slow the fuselage and trim is fairly level but when you fly faster this all changes

Trim the plane as directed in the early post

If flying along under high power and the plane immediatly tries to climb, you have too much positive wing incidence that is compensated for with down thrust.

Ideally the plane's trim could be set up to remain the same under power or in glide but they seldom are.

The Telemaster was a trainer with a lifting stabilizer to keep the trim the same at different speeds. There was also a Lazy Ace Bipe that had a lifting stabilizer for this purpose.

I put a shim under the rear of my LT-40 wing to decrease the positive wing incidence and settle the climbing tendency some.

I was wondering about this! I thought I was hitting serious wind or something...

Great thread.

For the first few flights of my Kadet Mk2 (OS 46ax & topflite 11*7 prop) It climbed like a devil when under full power. My buddies that I fly with figured it was the design of the plane. I had my cg set at 3" (manufacturer says cg @ 2 3/4 - 3 1/8.)


After closely reading the manual, Sig suggested putting the cg right at the front of the range as their Kadets responded best there for arobatic flight. I then set the cg @ 2 3/4". Now there is "almost" no climbing at full power. Loops, rolls and even inverted flight was dramaticly improved. Low & fast banked fly bys are not scary anymore. [X(]

Perhaps this setting is not adisable for beginers as throwing the throttle open alone will not pull you of of danger quickly without inputting elevator...

I should also add that landings are a fare bit faster now for me with my cg at 2 3/4.

I should add:

(my Kadet)
Main Wing incidence, 0 degrees
Evelator incidence, 0 degrees
Engine downthrust, 2 degrees
Engine Right Thrust, 3 degrees

As was already said, trainers are designed to fly that way. When I was under instruction, with my instructor on a buddy box (if you are not using a buddy box with an instructor, you are losing a valuable tool.)

An instructor should figure what is going on and why. In this case, once airborne, cutting the throttle to about half, then adjusting the trim for a straight and level flight should do it for you. The first thing you should do after take off is to trim at desired flight speed. Any changes in the throttle after that (any changes.. decresase and it will lose altitude. Add throttle and it will gain altitude) will result in a required re-trim for straight and level flight.

Simple as that.

CGr.

Trim it?

Just want to thank everyone for their informative input.I will try a few of the ideas presented and see what happens. Thanks again

I have some popsicle/tongue depressor sticks in my flight box that are very usefull to put under the back of the wing and once the wing is tightened down they stay put. If it works then do something permanent at home. I've not had to use more than two to make a big difference.
Fred

My answer may sound like disrespectful but i see it all the time. I've met afew who are self taught and never knew a plane could be trimmed. They were constantly fighting it in the air

You can also manually adjust both of your ailerons. Move both of them down a couple of clicks.

but as a model consume fuel..it's going to get lighter up front, so you're constantly trimming anyway.
Unless you mounted your fuel tank in between the wing ribs.lol

My Tower Trainer .40 Mk II ARF was initially set up completely stock with the standard engine mount and standard thrust angles built in. I had a .46 FX on the nose, which was a ton of power for this lightweight airframe. When I went to maiden the trainer, it just about launched itself straight off the ground and shot up like a rocket.

I had to add plastic washers behind the engine mount on the top two bolts to put a significant amount of "downthrust" into the engine setup. After that, I was able to trim out the airframe and get it to fly in a very neutral and well-behaved manner despite it's flat-bottom wing.

I would check the stabilizer as well to be sure it is parallell to the fuse.