I have a new Great Planes Giles 202 ARF and flew it for the first time yesterday. I took it up and trimmed it for level flight, it flew just fine. When I went to do a simple loop, the plane went into a quick roll to the right as if I threw in alot of aileron. I tried this at different speeds with the same result. Does anyone have any remedy to the problem? We checked everything on the ground and found no problems in the servo throws or linkages.

Specs: Great Planes Giles 202 ARF
O.S. 120 Surpass engine
Futaba T6EXA W/ S3305 servos

You might want to provide a bit more info, but what from you have provided I can think of two possibilities. Are your throws set too high on the elevators so that when you pull back on the stick shes snapping? There has been much posted on this subject with this airplane specifically and she will definitely snap when you pull back on the elevator if the throws are set too high. One way to test this is to get her up high and then at about half throttle pull back on the elevator all the way. If she snaps out of the loop then you have too much elevator throw. I would first want to make sure all the electronics are fine before flying it again.

Did you do a good range check to make sure your aren't getting any interference? Might want to turn on the switch and start the motor. Set the throttle to the same rpm where you think you are encountering the problem and then pull back the elevator to try and recreate the problem on the ground. Just my 2 cents. I had this airplane myself and I'm pretty familiar with how it flies. On one of these models I had a cracked ceramic filter in the Rx - per post crash testing from Hobby Services. I took off and then she went hard to the right and then straight up. I had no response at the controls and she went in.

Your problems sounds exactly like mine. I have the 46 size Giles 202 kit from GP and went down in the swamp Friday afternoon. Retrieved with minor damage. Post crash analysis revealed WAY too much throw on the elevator. I had it trimmed for good level flight and was making good passes. Once I decided to start the fun stuff, that's when the problem started. I went into a climb and at the top I started to pull backinto what was basically a slow loop. As the stick came back the plane violently snapped into a corkscrew dive, narrowly feathering out as it passed a line of trees and headed out into the swamp area next to our flying site. Credit two of my flying buddies for retrieving it for me Sunday afternoon. On subject, I will be making a few changes after repairing the damage...busted firewall. First I will balance it somewhat forward of the recommended CG and a little noseheavy. This plane feels very squirrely in a tailheavy config, IMO. I will also be lowering the throws via low rate adjustment on my radio setup. On low, I was still at 65%. Plenty of room for adjustment. Aileron throw seems very stable at max recommended throws, but elevator seems way too high. Good Luck and Blue Skies!

Check this thread.

http://www.rcuniverse.com/forum/m_10...tm.htm#1000160

or do a search for great planes giles

Lots of great info on this plane. And the guys above are probably right about the snap being due to too much elevator, there are about 100 warnings in this thread about the elevator settings. I have yet to get mine off the ground, watched it flown by a great pilot in Vegas, but my skills are just getting to the point where I'm getting her ready to fly in the next 30 days.

Check your elevator servos with some pressure on them. You may have a servo that is bad. The older hitec 605s were bad for this. They wouldn't hold center and lost power to move the surface. Been there already on these.

The snapping tendancy sounds like an accelerated stall, and this tendancy is common with the scale aerobatic planes. They have thin tapered wings and are much more prone to tip stalling than are fun flys and sport planes. You need to fly it more like a pattern plane (i.e. larger, more gracefull manuevers) and don't try to use large elevator throws except during 3D type manuvers where you are flying in a stall anyway.

On the other hand, if the problem is really servere and you cannot even use enough elevator to fly the plane comfortably, you might look for a construction defect that would trigger an early tip stall - in particular wash-in on one of the wings (that is, uptwist at the tip). I had a wash-in problem on an Edge and the plane was a nightmare to fly until I got a new (straight) wing.

Good luck,
Greg

I reckon the Giles is one of the most likely planes to snap when you use too large elevator throws.

My guess is the swept leading edge encourages it, as the CAP also snaps (slightly less sweep in the wing, with slightly less tendency to snap) followed by an Extra, with an Edge (which has a straight leading edge) snapping the least.

I also reckon it's exaggerated when the plane gets smaller.

Try less elevator throw. They are very pitch sensitive so less throw won't too adversely effect the loop diameter.

Also, make sure it is laterally balanced, especially if it always snaps in the same direction.

-David C.

David - The layout of the Giles is one of the best - but the real culprit is every last one of the commercial kits -of this design -for sizes up to 1000s quares - typically ends up overweight.
The EDGE wing planform is absolutely the worst wing layout for snapping - the saving grace is that the fuselages are much longer than the Giles ( distnce from CG to center of stabilizer)
I helped a friend scratch build a copy of the Midwest Giles --at 10 lbs - this plane was excellent - could be pulled very hard without doing the nasty high speed stall.
We use the same wing on our Dalotels . beautifu aerobatic layout -
In the 80's Hanno Prettner run roughshod over all the TOC flyers , using this layout - the smoothness and crisp snaps were still the best I have seen --and I was Line Chief last year at the final TOC-- so I have had a chance to see a good cross section of designs .
Even CHyde's Bipes have swept LE's

Thanks Dick. Interesting!

I reckon the scale effects (probably resulting from the different Reynolds numbers as a result of the size) actually completely change the characteistics of the classic aerobatic planes like the ones we are discussing.

I have no doubt the Giles is an excellent large scale (or full size!) configuration, but as the aircraft gets smaller it tends to suffer rather too much from snapping and tip stalling for my comfort!

-David C.

Dick to the rescue! Thanks for the info Dick, I always learn something when you respond

If the Giles is such a great design why dont the manufacturers pick up on these cues and build a plane accordingly? makes you wonder sometimes


matt

I concur with Dick.

I saw Hanno fly at the World Champs in 1991 and his snaps were superior to anybody elses.

I've only ever found the Giles to be a solid platform in various sizes and think that it is the most 'pattern' like of the aerobatic scale types.

Cheers

Phil

So, what's causing the unwanted snap in our friend's model here, then?

-David C.

Some of, or all of the above and I will add that I havent seen any mention of a rearward CG.

If the CG is well to the rear and there is a lateral balance problem then the plane will normally snap to the heavier side.

Cheers

Phil

Right on the money guys. Sam re did the elevator throws last night and took it out to check it out. Flys like a champ now. We did a thurough check of all the radio and serv possibilities the other night when we flew it and i was convinced it had to be Aero as opposed to mechanical but i would not have guessed that the elevator trow was the culprit. Never had that particular problem myself. What a great resource to have here!

Sean

Sean

Pleased to know it worked out

Cheers

Phil

Nice to hear it's sorted now.

I would still suggest you keep aware of a possible snap, both when going fast and slow.

Coming out of a fast downline, or making a slow landing or loop, for instance.

Enjoy!

-Dave

Sean, glad things worked out and thats all that it was. While you guys are at it, there are a few mods you might want to consider to add strength to the fuse and the wings. The fuse on this model has a history of flexing at the formers fore and aft of the wing saddle. The first signs of this will be a slight cracking in the covering. Place tristock strips with epoxy on both side of these formers to keep the airplane fuse from breaking in two in these areas. It's happened too often.

Also, peal back the covering on the wings in the area of the wing saddle and add some fiberglass cloth. I used finish epoxy for resin, which worked very well. I never had a problem with this after doing these simple mods.

Good luck and hope this helped.

Unless I missed something. Does it roll out or is it snapping? If it is rolling out check that each ele is moving the same distance. Had a cap that did that. Even though you could not see it I readjusted for the way it rolled and it was cured.

RFW 1953

Thanks for the tip. I wil check the formers and signs of flexing

Chers

Phil

Having read the previous posts and solutions offered, I am rethinking the elevator setup as I continue the repair process on my Giles front end. It's painfully obvious that there is an extremely large amount of elevator throw in the current setup. Using dual elevator servos is new to me but I got it to at least work, so adjusting the throw shouldn't be all that difficult. I made a huge blunder, admittedly so, in not checking the suggested throws out when I set the plane up the first time. Luckily it didn't cost me the whole plane, just some minor cosmetic damage. As soon as I get the plane back to par, I will post a pic of her. Great info here on this plane, keep it up!

Luke

Dual elevator servos are actually good stuff.

You can fine tune them and dont suffer the problems of the metal U horn flexing under load or tiny misalignments.

I now endeavour to use one servo for each elevator half on all of my planes

Cheers

Phil

Thanks Phil. I finally finished the repair work and she's as good as new. It took me about 2 seconds to fix the elevator throws. Thier a spot on match for the recommended now. Final balance will happen today at lunch, with test flights this evening, weather permitting. I can't wait to get her up flying again. I changed props from a 12x8 to a 13x6, both MA. The only APC I have is a 13x4 and it scares the daylights outta me.[X(]

Flew it at lunch...My plan to go nose heavy backfired.[X(] It came out OK, but it flew like a sick elephant. [:'(] Took forever to get up, then sagged around and landed like a screaming banshee. The gear sheared off the nylon bolts but no other damage. I have spent the afternoon rebalancing it, laterally also. All throws are now at factory spec as well. No more Mr. Nice Guy. [:@]This plane will fly properly or die. [>:]LOL I think I may have bitten off more than my limited flight experience can chew. I have plenty of low wing and bipe time, but nothing on a plane as nimble as this. I accept the challenge to learn to fly it properly and every time I get it down in one piece is a step in that direction. I don't have many people to fly with and usually end up alone at the old runway where we fly. That being the case I have done very well by building on the fundamentals and progressing into more advanced aircraft and flight styles. ANYWAY... The rain is abut to stop here so I may get to fly it again after work, Will post flight results and performance if successful.

P.S. Thanks for letting me ramble

WOW! OMG! OH YEAH! (Did I mention WOW!!!! ? )

I should have listened to GP in the first place! The recommended specs are dead on. This is my new favorite flyer.[8D] Performance was hindered slightly by the 13x8 prop so I will try switching back to the 12x8 for a little more speed in the vertical. It was very smooth as long as I was light on the elevator. Too much and it goes into a locked spin. I almost lost it again but I try to learn fast.

Balance required a little weight in the left wing and the battery under the gas tank.

WOW!

Sometimes when I get into a "do or die attitude" I then realize it's time to go home for the day. There is always tomorrow and it sure is better to make a simple adjustment than to rebuild, or reassemble an airplane. Just food for thought.

BTW- nice covering job.