On Wednesday, September 25, 2019 at 8:16:19 AM UTC-7, wrote:
On Wednesday, September 25, 2019 at 10:27:12 AM UTC-4, Dan Marotta wrote:
200'/mile works out to 30:1 since we all use nautical miles, don't we?Â*
That may work just fine back east, but out west not so much. It's
disconcerting to see on the CNII that I need 20:1 to get home but I
can't seem to do better than 15:1.Â* Yes, we have strong thermals, but we
also have some very impressive sink!

On 9/25/2019 8:11 AM, Tango Eight wrote:
On Wednesday, September 25, 2019 at 9:55:44 AM UTC-4, wrote:
Uncl, that is absolutely correct and what I was trying to express. The "perfect" flight would be one of relatively constant avg speed with little difference between normal task cruise avg speed and the final glide speed.

We all know however that that does'nt happen. Most of us do the best we can till we think we have our final glide in hand then modify our speed as we head on in depending on whats happening with our altitude.

On a related question, I wonder how many folks here could calculate and perform a successful/efficient final glide without their handy dandy flight computers?
200' per mile plus 1000', and you get home, even in an HP-18 :-). Back in the day an LNav was 20% of the cost of my glider and GPS wasn't even a thing yet. I had circles drawn on a map and eyeballs to check position. Worked every time, wasn't so hard.

T8

--
Dan, 5J

Most people I know use statute miles. I teach using 5 miles/1000 ft as a good final glide reference for Std or 15M ships. Easy to calculate. Adjust for conditions. Pretty much what Evan described but easier to calculate with GPS distance and altimeter.
UH

I have been having a fun summer teaching a Dou XL owner to fly XC. His GPS nor mine was not working for several months and I know the LX9XXX pretty well but didn't know his CNII so we have been using the method I first learnt, 5 statute miles per 1000 ft. We also worked hard on judging distances and estimating what our glide (altitude we would lose enroute) to any cloud, ridge, airport, all glides must be estimated and told out loud. For longer final glides, rather than use something other than 5 miles per thousand, we would add 5, 10 or 15 miles to our estimated distance as a safety factor. We also visually judged and evaluated each glide by the target moving up or down on canopy so we could quickly ascertain how our glide was going. I so much enjoyed the first part of the summer without the computer than we still are not using, at least in the back seat I am not.