Thread: CTLS AOI section 5.7 Gliding Characteristics

I asked my Instructor how to read the graph in the CTLS AOI section 5.7 Gliding Characteristics. He said the lines on the graph are indicated with the incorrect slope. I agree. How can you glide 14nm from 0AGL, and 0nm from 10k feet (and no fair circling)?

Does anyone else agree?

P.S. If I'm wrong here, please feel free (Read-> please save me the embarrassment) to delete this post.

Hi Netninja,

Your right it does not seem very intuitive, but if you find your altitude above ground on the left side, follow that horizontal to the right until it intercepts the graph for the appropriate flap setting, read straight down to the bottom. That value becomes the start reference. Subtract that from the value found at the end of the slope line "0" altitude and that would be the theoretic glide distance no wind. Example, if you are at 5000' AGL then your starting reference would be 7nm, subtract that from the "ground zero" of roughly 14 and you get a glide distance of 7nm. You can also estimate by taking 5000 x 8.5 (the glide ratio) and divide by 6076 the number of feet in a NM.

Regards

Eric Swisher
Copper City Aviation Services

Hi Eric,

Thanks for the explanation, I can understand it now. (Ground zero - reference = GD) I suppose it's just my engineering background showing through and attempting to simplify.

- Ed Tomlinson

Originally Posted by coppercity

... You can also estimate by taking 5000 x 8.5 (the glide ratio) and divide by 6076 the number of feet in a NM...

when i bought my ctsw glide was 16:1 later changed to 14:1. how'd the ls get to 8.5:1?

Not sure Charlie Tango, that was the book answer from the LS AOI. Seems a conservative compared to the SW. The published best glide speed is higher in the LS compared to the SW, so maybe that is causing the descent rate to be a little higher. Even though the aircraft are similar, those subtle changes in length, wingtips, gear etc can cause plenty of aerodynamic differences.

Eric