I've been flying trainers for a while now..and for some reason, I just can't get an aileron roll out of my superstar 40. I've tried up and down elevator at various points, as well as rudder both ways at various points, and all i can get is a half roll, then 90 degree snap straight down (like it's going to spin) then I have to up elevator and use the ailerons to correct back to level flight. I can do nice big loops, nice tight loops, marginal outside loops (gently), "hammerheads" (well , nearly, they still look neat), stalls, land and takeoff like a champ, but no stinkin aileron rolls!!!

Any ideas on how to practice this?

First thought that comes to my mind...are you for sure holding the stick over to the left/right all the time? Should be pretty obvious...Also, are you giving DOWN elevator when the plane is inverted after the half roll? It sort of sounds like you're giving it UP elevator when it's inverted, which would give you the instant dive. I have done that a few times when I was learning them. Also, make sure that the sticks are for sure going straight sideways unless you are giving it elevator. You may without thinking be pulling the stick to up elevator while applying aileron. Just a few things to think about. I know, one of the more experienced guys is going to come on here and say something simple that I never even thought of. LOL Oh, another thing you can do to practice is to point the plane up 4-8 degrees, and just give it aileron, no elevator. Once the plane loses altitude half way through the roll, it will end up about where your plane was in level flight.

The dehedral will pull a trainer down very quickly inverted. I would suggest you start your roll after a gentle climb, say 20-25 degrees and let it roll around completely. Dont worry about rudder or elevator correction just yet. It might help if you increase the aileron deflection to speed up your maneuver. It really sounds like you are rolling too slowly.

Once you can roll exiting the same elevation as you started, you can practice feeding in down elevator while inverted.

i can't imagine that you could fly inverted (outside loop) but you can't do a aileron roll... am i missing something? when you are inverted preparing to go an outside loop, you will need to roll and fly inverted. according to your claims, once you get halfway through (inverted by then) you go straight down!!!

anyway, i'd agree that you should try to get a shallow climb and try the roll without any elevator input. i'd also maybe add some deflection on the ailerons.

now i'm going to ask something stupid ... you have ailerons, right? i mean a lot of high dihedral trainers can be 3 channel planes.

Definitely increase your ailerons throws. I think that's your biggest problem.
Dennis-

itto, plus, make sure your aileron hinge gaps are sealed. That will make them more efficient

Have to agree with Minnflyer, seal your hinge gaps. When I did that to my trainer it actually became a fairly nimble bird. You can use monokote the same color as your plane, or use clear monokote. You can even use packing tape to seal the hinge gaps.

Also, give a little bit of up elevator before you start your roll. Then as your plane rolls inverted give down elevator to keep it from dropping out of the roll.

Hope this helps

Has an experienced flier tried it with your plane? With would be the quickest way to see if it is the plane or the pilot, I would think. If the plane, then find and fix the problem. If the pilot, find and fix the problem with a little training.
Recheck the cg on your plane too.

It sounds like you are holding some up elevator during the roll. You need to concentrate on using only 1 control until you become proficient, then try adding in some down elevator.

This is the roll procedures for trainers, scale planes and full scale, non-aerobatic planes. I taught these same procedures as a T-37 instructor for the Air Force.

Line up parallel to the flight line at full power and a safe altitude.
Do the maneuver "by-the-numbers," one control at a time.
1. Raise the nose about 20 degrees and release all the up elevator.
2. Put in and hold full aileron. As the plane rolls, the nose will come down to level about the time you are inverted, then drop below the horizon as you finish the roll.
3. When the roll completes, release the ailerons and use up elevator to raise the nose back to level flight.

If you need to know other maneuvers, check the R/C Report web site for back issues of my column. I do a maneuver every month. Most are for the regular sport flier with a few 3D's thrown in. [link=http://www.rcreport.ws]R/C Report magazine[/link]

I have the same plane, i can do it some of the time, but some of the time i can't. It's the aileron throw for sure

The Superstar will roll quite nicely. You need lots of throw on the ailerons (as much as you can get) & employ a little trick to help it. Don't wait until the plane has rolled inverted (or even to knife-edge) to input down elevator. Go to full throttle, raise the nose to ~ 20 deg above the horizon, then put in full aileron & push the stick all the way forward (full nose down) immediately after you put in the aileron (move the stick left or right, then forward as part of the same input). It will roll surprisingly axially. Be ready to return the stick to neutral & then add a touch of up elevator as it rolls upright. You will lose a bit of altitude, but not much. Stay at a safe height & try this in a vertical climb first to get a bit of practice.

You can also do an outside snap with the Superstar. Full throttle, nose up 20 deg, full aileron & rudder & full down elevator. Again, try this at a safe height & in a vertical climb the first few times.

The Superstar, like most flat-bottomed-airfoil trainers, is incapable of a decent inside snap -- the wing just won't stall in the roll.

britbrat,
I have this trainer and soloed on it last summer so I'm likely close to you in experience. 6 or so flights after solo i maxed my ailerons. but even b4 that I had no trouble rolling it. It wasn't pretty until I our club pres showed me the !QUOT!shallow climb and elevator input!QUOT! trick. Now rolls are nice. don't really need to climb if you get the elevator right. here's what he told me.

When wings go vertical (1/4 roll) start your elevator input so that by the time you're inverted you are at the max elevator you'll need to stay level, then you back off that input so that when you wings are vertical again (3/4 roll) you're off the elevator completely, then complete the roll. It's kind of a feel thing and takes practice to do it consistently.

As for inverted, my Superstar 40 with an EVO TPS will do it all day.

One thought. If the CG was way off and the plane was trimmed to fly well upright that way, wouldn't that CG problem cause major problems once the plane's inverted.

Also, I thought about sealing the gaps on my plane but the gaps seem really tight. Tight enough light will pass though in only a couple of small spots. Still worth sealing?

Most trainers need the help of the rudder to complete a roll. Get the plane on a slight inclined attitude, and then push BOTH sticks one direction or the other (but not opposite directions). 1/4 way through the roll, start to give some down elevator (while still holding right or left aileron). when completely inverted, hold enough down elevator to keep the nose up. Then, roll out using the same technique (begin to slowly release the down elevator as you roll out, until you are flying upright again, and have neutral elevator again.

Dihedral really has little to do with pitch either upright or inverted. I regularly fly 3 and four channel old timers inverted and they have very flat bottom airfoils and a bunch of dihedral. most people don't put in near enough down elevator at the right time to hold the nose from pitching down. Put in the down elevator at the right time and you can roll as slowly as you like.

Forestroke- I did not say i did GOOD outside loops, only that i could do them..marginally..[8D]..and as you say, I do have problems inverted with this plane (the outside loop looks decent until that point). It does not want to stay inverted at all.

Aileron throws are set to the book minimum...I'll increase those, and seal the hinge gaps. The plane WILL do it as it is; a buddy flew it and could do them, although he said they were pretty hard with the plane. He told me to re-do the wing without dihedral before I worried about too much stuff like rolls, but then again he had not flew a trainer in 4 or 5 years.

CG is toward the front a little at 3 1/8", well within the 3"-3.5" specified by hobbico. Plane is a 4-channel, Futaba radio, s148 servos, OS 40FP engine, 10x6 prop running cool power 15%.

Thanks for the help, I'll try some of this stuff out tomorrow if the weather's good.

It should EASILY stay inverted. I always can stay inverted for ever, just the flyings inverted gets me...

Newb - he may have built more dihedral into his than you did. This can make it harder although still doable.

bruce,
I think Newb was making a joke. He can keep the plane inverted, but keeping it inverted while flying gives him trouble.
Dennis-

I understood that. My point was that perhaps USMeagle has more dihedral built into his plane which could be adding to ALL of his problems. Just a possibility.

I think mine has the stock 5" It was a RTF

Aileron differential will make a flat bottom wing roll much better too. Especially if it has a lot of dihedral.

GOT IT!!


All i did was put a long (double arm) servo arm on, move the pushrods out to the last hole (which increased throw). Rolls like a champ now !! Made the plane a lot more fun to fly too, but I did have to "adjust" my landings..a little bit of stick does more than it used to!!

Thanks guys for the help!

US, i will probably use dual rates for that. My new radio will be here in the next 2 weeks

Glad you found the increased throws overcame the slow rolls.

Now, keep practising those rolls, loops and crosswind landings. Second plane isn't too far off.

Oh, inverted flight will be much easier now. Just keep it a couple mistakes high for awhile.
Dennis-

Chad,
you could also use exponential on this sticks if the radio has it(and I'm sure yours will). This will provide a "softer" response around center and still give full throw when fully deflected. Play with it a little, set it up as an alternate plane and take it to the filed and try it. if you don't like it, just land and switch back. NEVER try to change programming in flight. You'll only do it once per plane, if you know what I mean. [:@]