Contest space size - circle diameter.

[Peter in Fairfax, VA]

Summary:  How big of a space is needed to accommodate flying, with judges?

I know there are a number of stunt CDs on this board, as well as competitors with experience, so I'm posing a question about how to lay out a contest space.  Especially with respect to allowing for judging.

For solo practice, a flying space for stunt is typically a marked center area, like a concrete pad or small painted circle, combined with a 70' radius area for takeoff/landing, plus about a 10' buffer area, for 80' total radius.  However, to have an actual contest, or even to train judges for a proposed contest, I'd estimate a larger area is needed so that judges will be less likely to be struck.

Thoughts?

thanks,

Peter

[Tony Drago]

Maybe a square 200ft x 200ft.

[Tim Wescott]

I had typed "The 80' radius circle is the rulebook size".  But I was wrong -- it's not in the rulebook anywhere.  I think I found that dimension in an AMA publication about recommendations for control line sites.  So -- with 80', as a judge you're pretty much safe as houses outside of that circle -- even someone flying on 70' lines is going to have to stray a long way from the pilot's circle before their plane gets to the edge.  I'd say that if you provide any walkway -- even two feet wide -- you'll be OK at that diameter.

One of the fields I compete at has a smaller circle, to fit the available patch of pavement.  There's room around it to maneuver, if you're willing to walk on grass.  Toeing the line they have painted is (ehem) highly inadvisable, though, because in competition you'll often see planes flying with their wheels right over the line, and their wings hanging out beyond it.

Maybe a square 200ft x 200ft.

I think for multiple circles at a contest, if the circles were 170' center to center that would be more than adequate -- that would let judges walk around the circles without crowding each other.  But I think that if space is tight, and the only way you have to squeeze a flying field out of a space is to make things a bit smaller -- see what I said above.

[Trostle]

(Clip)

I think for multiple circles at a contest, if the circles were 90' center to center that would be more than adequate -- that would let judges walk around the circles without crowding each other.  But I think that if space is tight, and the only way you have to squeeze a flying field out of a space is to make things a bit smaller -- see what I said above.

You might want to correct that "90' center to center" recommendation.  You will have planes overlapping each other on adjacent circles unless you restrict line use to 40' or less unless the pilots have very short arms, then the lines could be maybe 43' and warn the pilots not to wonder more than a foot from the marked circle center.

Keith

[Trostle]

When laying out the size of a circle for a contest, keep in mind that 70' lines are allowed which are measured from the center of the handle to the center line of the airplane.  Then, you need to allow for the length of the pilot's arm (up to 3') and for the outboard wing which would be another 3' and allow for the pilot to wander around where the center of the circle which would be another 2 or 3 feet from the center.  (There is no specification on what the size of a marked center circle should be.)  So you have a path the outboard wing will cover will be a circle of almost 80 feet in diameter just for the airplane.  Then, there needs to be some distance allowed for the judges to be outside that radius.  They will probably be up to another 10' beyond that.  So, you will need to have space for at least a 90' radius circle for safety.  For a second circle, the centers should be at least 180 feet apart.  Yes, they could be a bit less, but then safety starts to be compromised.

Keith

[944_Jim]

Realistically, I would want more than 40' from plane to people for bigger planes like some of you fly. But for the puny stuff I usually fly (1/2A), being just outside the circle isn't so intimidating...maybe 25'

Consider also that the circle may centered in the square, even if the circle-path were right on the square's edges, you still have four significant pockets in each corner.

Where I fly is about 160 feet from corner to corner. Each  tangent meeting the center of a given side  is 80' to the center. From center of circle to each corner is 80 feet times the square root of 2...or about 120'.  I used to be worried about hitting the lamp poles marking the corners while flying on 50' lines on my square. Then I considered flying on 60' lines, so I ran the numbers. Even with a big pilot's circle, one would  still have a good chunk of safety. Now I'm trying to decide if flying on 60' lines over concrete is a good idea. I am not worried about clipping the poles, but the "hard landing."

[Tim Wescott]

You might want to correct that "90' center to center" recommendation.  You will have planes overlapping each other on adjacent circles unless you restrict line use to 40' or less unless the pilots have very short arms, then the lines could be maybe 43' and warn the pilots not to wonder more than a foot from the marked circle center.

Keith

Fixed.  Man, any time I'm juggling radius and diameter I always get something off by a factor of two.  In this case I added 10' to 80', instead of 10' to 2 x 80'.

[bob whitney]

and remember on landing the pilot could move five or 6 feet off center maintaning control of the plane

[bill bischoff]

Hey Bob, wasn't there a pilot who ran completely out of the circle? 


BB

[Brett Buck]

Summary:  How big of a space is needed to accommodate flying, with judges?

I know there are a number of stunt CDs on this board, as well as competitors with experience, so I'm posing a question about how to lay out a contest space.  Especially with respect to allowing for judging.

For solo practice, a flying space for stunt is typically a marked center area, like a concrete pad or small painted circle, combined with a 70' radius area for takeoff/landing, plus about a 10' buffer area, for 80' total radius.  However, to have an actual contest, or even to train judges for a proposed contest, I'd estimate a larger area is needed so that judges will be less likely to be struck.

Thoughts?

   80 gives you nearly no margin over max-length lines - the 70' is from the center of the airplane to the handle grip. Add in 2.5 feet for the outboard wing, and 2.5 feet for your arm, add in 5 feet for the pilot circle, 80'. I would suggest no less than 85 feet, 90 would be better.

    Brett

[bob whitney]

Hey Bob, wasn't there a pilot who ran completely out of the circle? 


BB

God will get u for the reminder