We are planning on taking our K-21B to a wave flying event and had a member say he recalled a possible concern with the canopy. His memory is not clear so thought I'd ask if anybody is aware of any history of canopy cracking while wave flying for this ship.

On 3/7/2022 6:42 PM, Mark Olinger wrote:
> We are planning on taking our K-21B to a wave flying event and had a member say he recalled a possible concern with the canopy. His memory is not clear so thought I'd ask if anybody is aware of any history of canopy cracking while wave flying for this ship.

How cold do you expect to get? Is it practical to limit your altitude to stay above, say,
10 deg F? Also, contact the dealer - he might have a good suggestion.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications

On Monday, March 7, 2022 at 9:42:02 PM UTC-5, Mark Olinger wrote:
> We are planning on taking our K-21B to a wave flying event and had a member say he recalled a possible concern with the canopy. His memory is not clear so thought I'd ask if anybody is aware of any history of canopy cracking while wave flying for this ship.

I would not expect a '21 canopy to be more likely to have a problem than other composite gliders that have a bonded canopy(most do).
UH

Thanks for your comments. Temps will be well below freezing but, as Hank says, it seems unlikely there'd be a problem. I've seen many ships of all ages at these events but wanted to do due diligence in that a comment had been made of possible concern.

Mark

On Tuesday, March 8, 2022 at 7:36:38 AM UTC-6, Hank Nixon wrote:
> On Monday, March 7, 2022 at 9:42:02 PM UTC-5, Mark Olinger wrote:
> > We are planning on taking our K-21B to a wave flying event and had a member say he recalled a possible concern with the canopy. His memory is not clear so thought I'd ask if anybody is aware of any history of canopy cracking while wave flying for this ship.
> I would not expect a '21 canopy to be more likely to have a problem than other composite gliders that have a bonded canopy(most do).
> UH

On the other hand: cracks in the gelcoat are not unheard of...

On Wednesday, March 9, 2022 at 2:15:09 AM UTC-5, Eric wrote:
> On the other hand: cracks in the gelcoat are not unheard of...

If you are flying a glider with integrated ballast tanks, make sure to open the drain valves and keep the tank vents clear. I was at a wave camp many years ago where a single seat glider climbed to 28k ft with the tanks basically sealed. One could see the shape of the tanks on the wing's surface nicely outlined by cracks in the gelcoat.

Uli
'AS'

We did two decades of regular wave flying with our two K-21s at Cal City.
No problems.
If the glider is tied outside, be certain to open and check spoiler boxes for no water/ice each morning.
Sop it out with a towel.

Things to do to make your life nicer in wave, in any area of the country with more moisture than we usually had...

interior clear view panels of plastic placed in the forward view areas, spaced off the plexiglass with skinny foam strip adhesive. This keeps your exhaled breath from freezing on the interior of the canopy and obscuring visibility.

Use insulated boots and snow suits for enough personal insulation, hats and gloves. An interior option for urinary relief is a bonus. External catheter into a leg bag works. The chill of wave flying causes capillary constriction and results in a full bladder more quickly than usual.

Hand warmer packets are a good thing, as are battery heated socks.

Know what time is sunset at local field. Allow time for VFR descent before sundown.
It's also a damn good thing to know how to benign spiral,
and how to make an emergency descent using parasitic drag.
If you don't know how to manufacture a safe ~4000 fpm descent,
I personally think you shouldn't be flying above 22,000msl .

Wave is breathtakingly beautiful,
and sometimes very demanding conditions to insert and
descend to landing. Get good training.

Safe soaring,
Cindy B

> Know what time is sunset at local field. Allow time for VFR descent before sundown.
> It's also a damn good thing to know how to benign spiral,
> and how to make an emergency descent using parasitic drag.
> If you don't know how to manufacture a safe ~4000 fpm descent,
> I personally think you shouldn't be flying above 22,000msl .

A rapid descent (or even a slow one) from high altitude can cause the gelcoat to crack. Dealt with that. It costed me a complete overhaul.
I don't want to scare anyone off -wave flying is beautiful- but you have to take into account that cracks will show up, even if you try to avoid turbulence or quick changes in temperature.

On Tuesday, March 15, 2022 at 12:31:09 AM UTC-4, Cindy Brickner wrote:
> We did two decades of regular wave flying with our two K-21s at Cal City.
> No problems.
> If the glider is tied outside, be certain to open and check spoiler boxes for no water/ice each morning.
> Sop it out with a towel.
>
> Things to do to make your life nicer in wave, in any area of the country with more moisture than we usually had...
>
> interior clear view panels of plastic placed in the forward view areas, spaced off the plexiglass with skinny foam strip adhesive. This keeps your exhaled breath from freezing on the interior of the canopy and obscuring visibility.
>
> Use insulated boots and snow suits for enough personal insulation, hats and gloves. An interior option for urinary relief is a bonus. External catheter into a leg bag works. The chill of wave flying causes capillary constriction and results in a full bladder more quickly than usual.
>
> Hand warmer packets are a good thing, as are battery heated socks.
>
> Know what time is sunset at local field. Allow time for VFR descent before sundown.
> It's also a damn good thing to know how to benign spiral,
> and how to make an emergency descent using parasitic drag.
> If you don't know how to manufacture a safe ~4000 fpm descent,
> I personally think you shouldn't be flying above 22,000msl .
>
> Wave is breathtakingly beautiful,
> and sometimes very demanding conditions to insert and
> descend to landing. Get good training.
>
> Safe soaring,
> Cindy B

May I add one more important item: know your O2-equipment! If you are flying above FL180, you will use a mask of some sort, i.e. one with a rebreather bag or even a military-style A14 mask.
I had the exhale valve on my mask freeze up in the open position, which meant that instead of drawing O2 from the rebreather bag, I was taking in outside air. Fortunately, I recognized my personal hypoxia symptoms from taking a high altitude chamber ride at the Dayton AFB and was able to remove the ice and make the mask function properly again.
Yes, wave is breathtakingly beautiful - literally! ;-)

Uli
'AS'

Good advice, Cindy.

I did a straight-in descent to the initial point for a 360 deg overhead
pattern in an L-23 from FL290, but I don't recall what rate of descent I
achieved. That was with full spoilers and a heavy slip. I'd be very
interested in your technique for a "safe ~4000 fpm ppm descent.

I don't fly that high any more, but sometimes it's difficult getting
down from just below Class A airspace.

Dan
5J

On 3/14/22 22:31, Cindy Brickner wrote:
> If you don't know how to manufacture a safe ~4000 fpm descent,
> I personally think you shouldn't be flying above 22,000msl .

Above 18,000' your primary instruments are your pulse oximeter and VNE vs. Altitude placard.

Dancing with the Wind by Jean-Marie Clément has an excellent evidence based chapter on oxygen that dispels a number of myths.

On Tuesday, March 15, 2022 at 1:54:27 PM UTC-4, georg...@gmail.com wrote:
> Above 18,000' your primary instruments are your pulse oximeter and VNE vs.. Altitude placard.
>
> Dancing with the Wind by Jean-Marie Clément has an excellent evidence based chapter on oxygen that dispels a number of myths.

I am intrigued now. What are these myths?
Does anyone have a used copy of this book and is willing to part with?

Uli
'AS'

On Friday, March 18, 2022 at 7:48:37 AM UTC-7, AS wrote:
> On Tuesday, March 15, 2022 at 1:54:27 PM UTC-4, georg...@gmail.com wrote:
> > Above 18,000' your primary instruments are your pulse oximeter and VNE vs. Altitude placard.
> >
> > Dancing with the Wind by Jean-Marie Clément has an excellent evidence based chapter on oxygen that dispels a number of myths.
> I am intrigued now. What are these myths?
> Does anyone have a used copy of this book and is willing to part with?
>
> Uli
> 'AS'

Some think it attempted to create some myths.

Mountain High is the standard.

https://www.mhoxygen.com/frequently-asked-questions/

Richard
www.craggyaero.com

On Fri, 18 Mar 2022 07:48:35 -0700 (PDT), AS <ulineumann@aol.com>
wrote:

>Wind by Jean-Marie Clement
>Does anyone have a used copy of this book and is willing to part with?

Try the new Google Books

Check out the new look and enjoy easier access to your favorite
features

<https://books.google.com/books/about/Dancing_with_the_Wind.html?id=5puArgEACAAJ>

This August I was gliding in the Alps, floating around for hours with
the oxygen on but not thinking much about it. That changed when we had
an interesting lecture at briefing from the author of this book.

Jean-Marie Clement takes his Nimbus 4 DM to the Andes every European
winter and has blasted round there for 11 years at huge heights, from
dawn till dusk, over high cloud, massive mountains and
do-not-land-here terrain.

After all that he is still alive. That fact plus his great experience
and research on high level flying makes him probably the leading
expert on the subject - anyway he has flown 2,182km at 178kph average
and holds 6 World and 27 French gliding records so, as you would
expect I sat up sharply and listened.

Jean-Marie preached oxygen use like a born-again Christian. He gave us
the latest information based on his vast experience, on experiments
done by himself and his friends, and on related laboratory research he
has been involved in.

He went to great pains to persuade us to use much more oxygen,
especially those of us not in the first flush of youth - and that is
all bar a handful of glider pilots, despite personal delusions!

Jean-Marie has just published this excellent book, in impeccable
English I might add, and three of us bought them the minute we saw
them in France in August and found them amazing reading on all aspects
of gliding, much more than just about oxygen and full of amazing
pictures, data and information like I never found before.
This book is of exceptional quality and, in my opinion, a must for
anyone wanting to glide above 5,000ft, or anywhere for that matter!

Le vendredi 18 mars 2022 à 17:58:13 UTC+1, JAB a écrit :
> On Fri, 18 Mar 2022 07:48:35 -0700 (PDT), AS <uline...@aol.com>
> wrote:
>
> >Wind by Jean-Marie Clement
> >Does anyone have a used copy of this book and is willing to part with?
> Try the new Google Books
>
> Check out the new look and enjoy easier access to your favorite
> features
>
> <https://books.google.com/books/about/Dancing_with_the_Wind.html?id=5puArgEACAAJ>
>

This link does not work, the title of my book has been “hacked”, this editor does not exist, do not send any money!.
You can get it directly from the USA at Cumulus Soaring or Wings and Wheels, and, in the unlikely case they sold their stock, you get it directly from my website www.topfly.aero .
All the best, and remember, before take-off, canula on the nose and EDS ON position N or F, never D!

On Sat, 19 Mar 2022 00:58:16 -0700 (PDT), "jean-mari...@gadz.org"
<jean-marie.clement@gadz.org> wrote:

> <https://books.google.com/books/about/Dancing_with_the_Wind.html?id=5puArgEACAAJ>
>>
>
>This link does not work, the title of my book has been "hacked", this editor does not exist, do not send any money!.

Google Books is legit, and Google does list two ISBN numbers

9788890343247, 8890343249

<https://www.google.com/books/edition/_/5puArgEACAAJ?hl=en>

Google lists this book, but says

"No results for this edition" and says
"Preview unavailable"

Google suggests to get it at a "Public Library"

Google is not pointing to a site where it can be bought. But, Google
does suggest getting a similar named book with a different title.

Title of your book has not been hacked....my error for posting this
URL...Apparently, Google has listed books not available.

> On Sat, 19 Mar 2022 00:58:16 -0700 (PDT), "jean-mari...@gadz.org"
> <jean-mari...@gadz.org> wrote:
>You can get it directly from the USA at Cumulus Soaring or Wings and Wheels, and, in the unlikely case they sold their stock, you get it directly from my website www.topfly.aero .

It's nice that Dr. Clement is listening in; his book is highly valuable in explaining the physiological responses to high-altitude flying, IMO. Soaring Mag August 2018 has an article discussing related issues.
I think Cindy Brickner's comment on developing skills for executing a high-altitude rapid descent could save your life. Keep in mind, a loss of supplemental O2 at low pressure does not produce the same pulmonary condition as simply holding your breath which most of us can do for a few minutes (false sense of security). Residual O2 is still in your lungs for your blood to exchange with. At low pressure, oxygen is forced from the blood into your lungs such that a loss of consciousness can occur in about 10 seconds. Moreover, we published an MRI study that showed many U2 pilots that had equipment failure had mini-infarcts in the brain (at least one pilot died when she had LOC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3776459/ Depending on the altitude, merely sucking on 100% O2 may not be enough, so very high-altitudes require a pressurized system. "AR" commented that hypobaric training revealed that he was able to "....recognized my personal hypoxia symptoms", which are different for each of us. I found mine after the rear pilot discovered he was pinching off my O2 supply with his knee.
A ? to Richard Pfiffner: What do you mean that some feel the book "....attempted to create some myths."???

Phyllis

On Saturday, March 19, 2022 at 1:29:13 PM UTC-6, phlyi...@gmail.com wrote:
> > On Sat, 19 Mar 2022 00:58:16 -0700 (PDT), "jean-mari...@gadz.org"
> > <jean-mari...@gadz.org> wrote:
> >You can get it directly from the USA at Cumulus Soaring or Wings and Wheels, and, in the unlikely case they sold their stock, you get it directly from my website www.topfly.aero .
> It's nice that Dr. Clement is listening in; his book is highly valuable in explaining the physiological responses to high-altitude flying, IMO. Soaring Mag August 2018 has an article discussing related issues.
> I think Cindy Brickner's comment on developing skills for executing a high-altitude rapid descent could save your life. Keep in mind, a loss of supplemental O2 at low pressure does not produce the same pulmonary condition as simply holding your breath which most of us can do for a few minutes (false sense of security). Residual O2 is still in your lungs for your blood to exchange with. At low pressure, oxygen is forced from the blood into your lungs such that a loss of consciousness can occur in about 10 seconds. Moreover, we published an MRI study that showed many U2 pilots that had equipment failure had mini-infarcts in the brain (at least one pilot died when she had LOC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3776459/ Depending on the altitude, merely sucking on 100% O2 may not be enough, so very high-altitudes require a pressurized system. "AR" commented that hypobaric training revealed that he was able to "....recognized my personal hypoxia symptoms", which are different for each of us. I found mine after the rear pilot discovered he was pinching off my O2 supply with his knee.
> A ? to Richard Pfiffner: What do you mean that some feel the book "....attempted to create some myths."???
>
> Phyllis
https://www.smithsonianmag.com/air-space-magazine/killer-at-70000-feet-117615369/