Control Line Flying Circle Build Questions

[Roy Johnson]

Wanted to put this up in the general section. In the future I'm looking at possibly acquiring a bit of land and making a grass flying circle to use to practice mostly stunt. Up to 70' lines. Looking for tips as far as the ground work requirements as far as drainage, total diameter, slope from center to flying circle. and any other thing I missed. This would be roughly in the Mid East Piedmont region of Virginia. I really like building so don't hold back.

Thanks,

Roy

[Dan Berry]

If you're hiring a dirt guy the operative words are " level to grade".  Otherwise you can wind up with a flat circle that is five feet higher on one side.

[John Skukalek]

Nearby trees can impact turbulence

[John Rist]

My guess is that you need a 200' x 200' lot.  This gives a 30 ft buffer zone past the 70' circle.  I tried to look at the AMA web sight for a circle layout but no luck.  Lost of RC but no control line.

[Dave_Trible]

I think the most important things are FLAT-no slopes-don't worry about drainage.  If you are concerned about that mix in a high sand content to allow water to soak away quickly .   Trying to fly on anything other than flat will be an issue to your flying.  My circle is 80+ feet from center to outside.   We have a 5' diameter concrete center pad.  It has settled some so we will likely put a new cap on top at some point and will go a little bigger,  maybe 7-8 ft. diameter.  Making and keeping it smooth is important.  Moles and ant hills and winter frost heave are always a struggle.   If you can get a roller and use it two or three times a year .  A grass that can be cut very short and not require great amounts of water is desirable.  We are planning to put in a concrete takeoff strip next spring.  Our thought is five feet wide by twenty five long.  The reasons are to help keep dust out of the engines and allow flying small airplanes, even 1/2A from the pad.  We find it takes at least 2 1/4" wheels to fly most anything off grass without problems.

Dave

[Angelo Smyth]

Hi Roy,

I developed a C/L circle on my property about six years ago. I brought-in a guy with a backhoe and a road grader to remove those pesky Mesquite trees (he even removed the roots, so they wouldn't reappear), and level-out the ground. My circle measures approx 86 feet from center to outside edge and generally speaking, the site has around another 15 feet of easement around the circle. There's a very slight slope going down from the southeast corner to the northeast corner. It's imperceptible when flying, but when it rains, you can see the water on the ground slowly going in that general direction.

Since I live in AZ (it's DRY here - we average around only 9 inches of rain per year in my area), I needed to install a sprinkler system (25 heads total) and plant some proper grass for my area (Bermuda grass). The grass has filled-in nicely year-after-year, and it's nice to fly from (whenever I actually get time to do so....another subject). The grass goes dormant in the winter months, and will green-up nice when it gets hot. It becomes lush whenever it receives alot of water (combination of watering along with summer rains).

It was a great project to do, and am glad I did it. But, I had to do it in stages, since I work a regular job. And doing it all at once would have been a substantial chunk of change, so doing it in stages softened the blow. Let me know if you have any questions, and I'll be happy to reply. Good luck with yours!

[M Spencer]

ANYTHING like THAT , you want the ground to ' season ' for a time , if you can . AFTER it is ' CUT ' .

As In , shovel / bulldoze / grade the sucker . LEVEL .  ( or slightly dished / domed )  If its CLAY its not really dusty . beeswax & sheepskin slippers will polish it smooth . Ahem .

The IDEA is to let it settle BEFORE you seal it ( if youre going to ) STILL , a uniform depth of topsoil , on that , would be more consistant .
So suckers mix dry topsoil & sand in a cement mixer ( the little powered ones ) as if yourre where it RAINS you need sandy soil for GOOD DRAINAGE .

HERE the big megabuck concrette coicill has a big ' whoop ' or dip , in one place . WHERE THE FILL HAS SETTLED . As Fill settles . so you leave it a few seasons . Or Compact & roll it . severly .
Lime Fill swells damp . Granite Chip compacted & rolleds stable , if youre in a hurry . ( Builders Tips - Lime Backfill can dislocate a concrettte block retaining wall . Oh DEAR . )

A level few inches of lime , raked and rolled , on the ' flight ' circle - would be a good base for a few inches of soil , on a Grass Circle . Your Local Bowling Green Constructor may be able to help . 

[Fred Cronenwett]

You might want to think about where you will roll out the flying lines when you get multiple models out there. Also remember that the radius for the lines is 70 feet but give your self an extra 10 feet all around to allow for arm length and models with long wingspans. I fly an 8' span B-29 with 65' lines, but if I was on 70' lines and my arm at full length It would create an 80' circle at the wingtip.

Since with CL stunt you tend to move around some at the center that extra 10 feet can be easily used up.

We have a several CL circles at Buder Park in St Louis and one has a concrete carrier deck but it also has a concrete center pad for the pilot to stand on. If you were to put down a 4" thick concrete center pad with a minimum 5' radius you will really like. Regardless of the ground conditions you will have good footing while flying.

[john e. holliday]

Dave , the park department now rebuilding ball diamonds and soccer fields, you think they might go with a little help on the circle.  so far as I know they have not pitched in on the stuff we have put in.  I have a couple of kits I will donate for a drawing to raise money for the project.  Let me know.

[Dave_Trible]

Well thanks Doc.  I'm not going to hold my breath on any help from the city.  That's OK as long as they keep the field set aside for our use.  I need to go visit the new Park Dept. Director lady and have acknowledgement from her.   I also want to run the project by her on the strip before we get into it so that they understand and approve.   If we are going into our pockets for this I don't don't want any surprises.   You and I have already put too much cash and work into it... I don't think there will be any problems but ........We will need to bring in a concrete truck for something that big.  All the local concrete companies run trucks every day to the sand plant down the road.   Maybe we can work out something...

Dave

[Ty Marcucci]

If the Park Director is a "lady" and you are a guy looking to have fun flying toy airplanes, GOOD LUCK with that. Past experience with any female in charge will do what ever to ruin your chances of any enjoyment....it's just their nature.

[M Spencer]

Any Fill is liable to sink .