Of those who have experience with this plane, what would you say the L/D ratio of this plane to be. My guess was from 20 - 30, but in hand tosses, I found it to be close to 12 at best glide. I find this low, since it seems to be a clean design.
There could be problem with my build, I have a feeling that leading edge is a bit thicker than it should be.

For reference, are there any known L/D figures for popular planes like Gentle Lady, Wind dancer etc.

My WW Sport 2 Hang glider is at 10 and Grob 103 sailplane I flew couple of times is 36.

Originally Posted by willfly

Of those who have experience with this plane, what would you say the L/D ratio of this plane to be. My guess was from 20 - 30, but in hand tosses, I found it to be close to 12 at best glide. I find this low, since it seems to be a clean design.
There could be problem with my build, I have a feeling that leading edge is a bit thicker than it should be.

For reference, are there any known L/D figures for popular planes like Gentle Lady, Wind dancer etc.

My WW Sport 2 Hang glider is at 10 and Grob 103 sailplane I flew couple of times is 36.

all i can say is ,,i wish my wills wing ramair had a glide ratio like the skimmer

Originally Posted by willfly

Of those who have experience with this plane, what would you say the L/D ratio of this plane to be. My guess was from 20 - 30, but in hand tosses, I found it to be close to 12 at best glide. I find this low, since it seems to be a clean design.
There could be problem with my build, I have a feeling that leading edge is a bit thicker than it should be.

For reference, are there any known L/D figures for popular planes like Gentle Lady, Wind dancer etc.

My WW Sport 2 Hang glider is at 10 and Grob 103 sailplane I flew couple of times is 36.

You can't measure L/D close to the ground (from a hand toss). Ground effect would exagerate the results.


What part of NJ are you from?

Plainsboro, close to Princeton.

Originally Posted by John Gallagher

You can't measure L/D close to the ground (from a hand toss). Ground effect would exagerate the results.

OK. So how can we get L/D figures for a plane?

Also, how much would you say ground effect adds? Is there any way to measure ground effect?

Ground effect can reduce induce drag by 50% or more. Also when you hand launch a plane you are giving it an uncertain amount of energy, you aren't just inserting it into the moving air wth all the forces in equilibrium. You can't get the L/D of a plane accurately without using a wind tunnel.

The EagleTree telemetry/recording system allows velocity and altitude to be measured, but
a) I am not sure if it is accurate enough.
b) From my altitude only recording tests using a RAM2 I know that even on totally still evenings the air is moving gently, and every glide results in differing sink rates, varying from eg 50 fpm to 80 fpm.

Neil.