When applying up elevator, the giles rolls hard to the left. It seems to only do this in the last half of the elevator travel on the way up (i can use a little bit of elevator to fly around, but anything over 1/2 and it rolls on its back). Does anyone have any idea how to fix this?

I have already checked:

1. Lateral balance
2. Elevators are exactly level with each other and travel together.
3. CG is at 5 1/8". The book says 5 1/4", but that seems very unstable.

Can anyone help?

chris

It sounds like too much elevator throw. what does the manuel recommend? how much does yours travel?
Not for certain, but it sounds like its snapping.

the manual recommends 5/8" high rate and 3/8" low rate.
The problem happens on either setting, but I did most of the flight on low rate.

What is "snapping"?

thanks for helping

chris

Are you talking about the 1/4 scale Giles?

If so then if I remember correctly, you can balance from either the LE or TE. Both gave a different number you arrive about the same place I think.

Just something you might want to check. There was an issue about this last fall. Its been awhile since I had mine so some one else may know more. I've probably got it all screwed up.

Dave

Hi thanks for the reply. No it isn't the 1/4 scale giles. It's the great planes .46 size kit. It's got ~60" wingspan and weighs 7.5 pounds.

Thanks for any other ideas you might have guys.

chris

I'm sure their will be some more elaborate explanations coming, but snapping is the wings stalling due to lack of air flow over them. useally from too much movement from the elevator.
Now when you say apply up elevator the plane rolls left. does it do anything else that seems squirly? like does it seem to porpoise during landings. (does the nose seem to want to bob up and down?) does the nose continue to drop when it rolls left if you hold elevator? does the plane do a fairly tight loop with only half elevator input?

Hi again 2lo. The plane doesn't seem to do anything else strange. It doesn't do a tight loop on 1/2 elevator. I'm wondering if I didn't do the lateral balancing correctly though. Any tips on how to do this properly?

I used some twine and hung the plane from the prop shaft as well as the fuse just in front of the stabilizer. Should I use thinner string (like fishing line)? Should I hang the rear string somewhere other than in front of the stab? Like the tail gear wire? I was afraid i'd snap the tail gear off.

It seemed to me I could make it tip either way just by nudging it one way or another.

Thanks again!

chris

doesn't sound too much like lateral weight is that far off you probably would have noticed a lot of trim input intially. try fly the plane several mistakes high,slow the plane down enough to where you gradually input all the elevator till it stalls if everythings ok it should stall nose first with out much wing drop from either side. from what I understand the slower you fly the plane the more input from the elevator is required to stall the wing.

http://www.rcaerobats.net/trim_chart.htm

try this website also for some info,I'm still learning all these little trade secrets myself.

thanks again. I'll give that stuff a try and post again when I have more results.

chris

The snapping is normal for the Giles. Keep your speed up and reduce your throws. You may try to add some aileron deflection but I don't think that will help. I have the 1/4 scale version and it will snap with excessive throw.

I'm flying the .46 size kit with TT 91 FS that weighs 7.5. I followed the recommended throws (updated throws that is.) I do have a lot of throw on full rates and let me tell you I left them on by accident while taking off and almost snapped it in to the ground on take off. Mine snaps (or rolls hard) to the left just like you describe on excessive throws. I fly mine sport and that is all. I think what you are experiencing is normal for this airplane.

My throws are set up as follows

Elevator duel rate: 5/16 (flies great)
Full rate: 3/4

What you are experiencing is normal for this plane. mine does, it all i've seen do it also.

this plane has a sharp leading edge and snaps like crazy. (that's what i like about it)! if it is happening when you don't want it to, you should reduce your elevator throw.

i have not been able to execute harrier or elevator type manuvers with this plane. in a blink it will be on it's back.....

David Soniat - Tampa, FL

ok. you guys are saying this is normal, but then how do you land the airplane? I've had it up for 3 flights so far, and as I try to flare on landing, it banks hard and catches the wingtip. The first 2 landings I damaged and repaired it. The third landing I managed to counter the roll with right aileron.

My elevator throw is on the lowrate setting (3/8"). You still think that it should be behaving that way?

What do you have your elevator throws on?

thanks for the help

chris

smatty, this is just my opinion,but I would take out half of the travel in the elevator, would'nt even try to flare for a while till you got used to it, and land it a little hot for a while.

smatty_mcfly,
You are stalling the plane on landing. Either land faster or move the CG farther AFT. This should reduce the landing speed.

Alright thanks guys. Lots of great ideas there.

I'll try a bunch of them out next chance I get to fly (tomorrow probably). I'll post again when I have more info.

chris

Mine kinda floats to the ground nicely, I don't try and bleed any speed off of it and end up taking a good distance to land but mine does land quite nice.

I read another post somewhere on this forum where someone had mentioned they had called Great Planes and they were told that this plane should NOT exceed a weight of 7lbs.

I can't remember the thread this was on but if it is correct, wouldn't this severely hamper the planes flying abilities?

Hi there Nex. The Great Planes manual says the plane should come out at 7.5 pounds, and mine hits that exactly. Hopefully it is correct.

chris

Do not remember the weight, but it did have a terrible snap with the recomended full low rate elevator.

Never had a landing problem, but then again, I hate to flair much. I like to softly plant them in the grass and let the grass slow it down.

This practice was hard to overcome when I got my hands on a thunder tiger cub, so I sold it.

But, this practice is needed for my current pattern plane. If I tried a scale flair, it would float 300 yards before leaving ground effect.

I modified my landing gear by shifting it a full 2 " forward of its stock position. The plane was ok, but in my opinion, not worth the time to build.

i can't get out to the field until tomorrow, but i'm thinking of trying an elevator->aileron mix. I've currently got it setup to apply 0" up to 1/16" of right aileron as elevator goes from 50% to 100% up(and no right aileron whatsoever between 0 and 50% up elevator).

has anyone else tried this? I realize the plane will probably respond differently to this at different speeds, but I thought it would be worth a try.

chris

Instead of programming in opposite aileron, try deflecting both ailerons up a bit. I had a Midwest Giles that acted very similarly. I deflected the ailerons up about 1/16 to 1/8 of an inch and the problem all but vanished. This helps to slow the stall of the wing, similar to having washout in the wing.

Gary Hunt
Rantoul, Il

thanks imacflyer. Do you mean to deflect the ailerons up a bit all the time? or just when elevator is in the last 50% of its travel? just on approaches?

thanks

chris

It would be best to simply deflect them permanently at the linkages. If you wanted to, you could probably set up a mix with your radio. With mine, I just adjusted the linkages and it stayed that way.

Good luck!

gh

thanks imacflyer i'll try that. I put 4 more flights on it today using the aileron mix, and it helped quite a bit (with landing at least). At speed, if I give it full up elevator, it still corkscrews instead of a nice straight loop. Perhaps the double aileron deflection you suggest will help.

Thanks to everyone for your help!

chris