Final glide

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

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

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.

Yep, me too, did it old school for years and even this year flying the 1-26 championships in Moriarty where my flight.computer was inop. No big deal. Except with my bird its more like 350 ft/mile lol I usually ballpark 4mi/1,000ft with the sink and the ever present headwinds lol.

The Classic 1-26 - never more than 2 minutes from landing!

On 9/25/2019 10:02 AM, wrote:
Yep, me too, did it old school for years and even this year flying the 1-26 championships in Moriarty where my flight.computer was inop. No big deal. Except with my bird its more like 350 ft/mile lol I usually ballpark 4mi/1,000ft with the sink and the ever present headwinds lol.

--
Dan, 5J

OK....sorta "tongue in cheek".....for fun.....a couple of YOUR recent contests had winning task speeds BELOW what I could do (stall speed) in 002 at my weight.....yes....being a PITA.....
Yes, ideal is minimum speed (task average speed) at legal finish height....some peeps have lost a first in a worlds due to 2 many circles across more than a week....

I remember a regionals at Dansville where I got stuck for over an hour.
Spratt man called my finish from the hanger while drinking beer with the rest of the fleet.
Back then, first landout points was based on last finisher.....I think I was maybe 18mph....in a -20?.

LOL truth Charlie, we are surely not speed demons. But I'll tell ya we have had a few guys, namely Ron Schwarttz, Mark Keene and Daniel Sazhin who have won days at speeds in the high 50mph range. Thats doing something in a 1-26! lol.

This last weekend while racing in a local xc series down here, I had, I think it was, a ventus 2 come blasting past me on final glide. He called to me to look to my right and I saw him blast past me at least 70 mph faster than I was going lol.

I got the last laugh on the glass boys in my division however, by winning the day with my handicap lol.

wrote on 9/25/2019 5:41 AM:
On Tuesday, September 24, 2019 at 8:14:29 PM UTC-4, wrote:
Truth, and a final glide made at max l/d tells me that the guy already screwed up. The perfect final glide is one that gets you home at the proper altitude and at the max speed. He just screwed up on both counts.

The "perfect" final glide has the pilot crossing the finish at his selected height and at at the same speed as the average for the flight.

You don't really do that, do you? I'll bet you fly the final glide rather slowly
if your final thermal is weak, and rather fast if that thermal is strong, and
don't pay any attention to how fast the flight was before the final thermal.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Wednesday, September 25, 2019 at 2:14:48 PM UTC-4, Eric Greenwell wrote:
unclhank... wrote on 9/25/2019 5:41 AM:
On Tuesday, September 24, 2019 at 8:14:29 PM UTC-4, wrote:
Truth, and a final glide made at max l/d tells me that the guy already screwed up. The perfect final glide is one that gets you home at the proper altitude and at the max speed. He just screwed up on both counts.

The "perfect" final glide has the pilot crossing the finish at his selected height and at at the same speed as the average for the flight.

You don't really do that, do you? I'll bet you fly the final glide rather slowly
if your final thermal is weak, and rather fast if that thermal is strong, and
don't pay any attention to how fast the flight was before the final thermal.

That depends on the task. The MacCready theory for final glide speed that depends only on the climb rate in the last thermal applies to assigned tasks. AATs (TATs) are different, *if* your decision (last thermal) happens before the last turn, so that you can then choose, e.g., to fly farther into the last turn area but do the whole final glide (from the last thermal to the turn to the finish) slower. In that case, the optimal speed is the MC STF that corresponds to the average climb rate over the whole task. Yeah I know it sounds weird. Reference: the Brigliadoris' book.

On Wednesday, September 25, 2019 at 2:31:32 PM UTC-4, wrote:
On Wednesday, September 25, 2019 at 2:14:48 PM UTC-4, Eric Greenwell wrote:
unclhank... wrote on 9/25/2019 5:41 AM:
On Tuesday, September 24, 2019 at 8:14:29 PM UTC-4, wrote:
Truth, and a final glide made at max l/d tells me that the guy already screwed up. The perfect final glide is one that gets you home at the proper altitude and at the max speed. He just screwed up on both counts.

The "perfect" final glide has the pilot crossing the finish at his selected height and at at the same speed as the average for the flight.

You don't really do that, do you? I'll bet you fly the final glide rather slowly
if your final thermal is weak, and rather fast if that thermal is strong, and
don't pay any attention to how fast the flight was before the final thermal.

That depends on the task. The MacCready theory for final glide speed that depends only on the climb rate in the last thermal applies to assigned tasks. AATs (TATs) are different, *if* your decision (last thermal) happens before the last turn, so that you can then choose, e.g., to fly farther into the last turn area but do the whole final glide (from the last thermal to the turn to the finish) slower. In that case, the optimal speed is the MC STF that corresponds to the average climb rate over the whole task. Yeah I know it sounds weird. Reference: the Brigliadoris' book.

I was commenting related to a preceding post that mentioned being very fast at the line. To have enough energy to be very fast one usually will have flown too slowly earlier in the final glide (assumes that one did not encounter surprise of very good air along the way). We used to do that so we had enough energy to pull up to fly a pattern. We pretty much don't do that any more.
UH