Thermals and Tandems

[rhys 0]

Hi,

I posted this here as It is most likely that experienced tandem instructors would have some sort of experience with these.

Yesterday we had a relatively busy day and half way through the piece (not long before we went on a weather hold!!) I had a lightweight girl (and I am not so chunky myself) and we were at 3000' for some minutes! I have done some ground launching but no para gliding so my experience is little with thermals.

I was spiraling and trying to fly over different surfaces to lose some height but.... I couldn't!

It was kinda cool and I was thinking maybe I should try to ride it as high as I could but the 4 people waiting on the ground and my tired biceps told me otherwise. Not long after we landed, the wind was gusting over 28 knots on the ground so I was glad for my decision.

Has anyone else had this sort of thing? I am on the equator, next to one of the highest freestanding mountains in the world and there is a hurricane only a couple of thousand kilometres away so I guess some thermals are to be expected.

I heard of a woman being taken above 25000' on a paraglider not too long ago but I guess that is not too likely on a parachute?




Rhys

"When the power of love overcomes the love of power, then the world will see peace." - 'Jimi' Hendrix

[vpozzoli 0]

Quote

Hi,

I posted this here as It is most likely that experienced tandem instructors would have some sort of experience with these.

Yesterday we had a relatively busy day and half way through the piece (not long before we went on a weather hold!!) I had a lightweight girl (and I am not so chunky myself) and we were at 3000' for some minutes! I have done some ground launching but no para gliding so my experience is little with thermals.

I was spiraling and trying to fly over different surfaces to lose some height but.... I couldn't!

It was kinda cool and I was thinking maybe I should try to ride it as high as I could but the 4 people waiting on the ground and my tired biceps told me otherwise. Not long after we landed, the wind was gusting over 28 knots on the ground so I was glad for my decision.

Has anyone else had this sort of thing? I am on the equator, next to one of the highest freestanding mountains in the world and there is a hurricane only a couple of thousand kilometres away so I guess some thermals are to be expected.

I heard of a woman being taken above 25000' on a paraglider not too long ago but I guess that is not too likely on a parachute?




Rhys

You where likely experiencing suction from a big cumulus cloud. Hence the strong winds on the ground (it's air rushing in to replace the air that's being sucked up by the cloud), and the subsequent wheather hold. This is what happened to the lady in Asutralia.
Vertical winds in a well developed cumuls can exceed 30 m/s which is impossible to escape short of cutting away your main and then opening your reserve waaay low hoping not to be sucked back in.
That is if you happen to be directly underneath and actually get sucked in, in your case there must have been enough distance between you and the actual cloud for you to only experience some difficulty losing altitude.
Should it happen again I suggest you start spiralling like crazy or better yet do not jump at all.
I'm not kidding, people have been killed or maimed by cumulus clouds, some of them where actually skydiving and not paragliding.
Cheers,

Vale

[BIGUN 1,050]

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I'm not kidding, people have been killed or maimed by cumulus clouds, some of them where actually skydiving

Go program something.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[vpozzoli 0]

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I'm not kidding, people have been killed or maimed by cumulus clouds, some of them where actually skydiving

Go program something.

Are you just being rude for the sake of it or are you claiming that this never happened?

http://www.cornizzolo.it/accadde.html

Here is a short summary in case Babelfish should do too poor a job of translating it into the language of your choice:

On July 24th 1988 three hang-gliding pilots lost their lives in the Italian Alps (near mount Cornizzolo) as they where sucked into a suddenly forming cumulus cloud. A fourth did not die immediately but died thre days later in the hospital because of the severity of the injuries he suffered. Others escaped more or less miraculously without major bodily harm.
Their names are Memo La Rocca, Guido Baruffini, Antonio Legranzini and Marco Lietti, just in case you might want to get in touch with their families and tell them you do not believe their loved ones dies as described in the article I referenced

On the same day in Aosta a Static Line student was sucked into a luckily much smaller cumulus cloud and landed some time later about 40 miles from the actual airport, only half conscious from exposure and oxygen deprivation and suffered serious injuries upon landing (she was to all practical purposes unresponsive).
She survived but never jumped again, if you like I can try and get in touch with her and suggest she give you a call to confirm my version of the facts which is still only 2nd hand (I only got it from my instructor who was instructing her on that fateful day)?
In the future if you have no idea what you're talking about may I recommend to you a good dose of STFU?

Cheers and safe jumps,

Vale

[SkymonkeyONE 3]

I have been stuck under canopy for over 15 minutes on a hot day before. Yes, that's after dumping at five grand with a tandem. My ex-wife stayed aloft at roughly 1000 feet on her 10th jump for like five minutes one day at Raeford. She was jumping a Manta and was doing little 45 degree turns back and forth right over the runway. All I can tell you is that if you continue doing slow circles over objects which create thermals (hot runways, forrests, etc), then you are going to continue to stay aloft longer than you want. Slow circles in such thermals (or updrafts) will not get you down. Get out from over wherever you are, man up, and spiral hard to get down past the thermal. As hard as your passenger can tollerate anyway. This happens to me quite alot, actually, when I am jumping smaller passengers.

Chuck

[BIGUN 1,050]

Yes, I was being sarcastic. You took the exception and made it sound like the media's persepctive of that being the rule. Truth is, a lot of us have danced with the cumulous clouds and "use" them for more hang time. Some of us have "inadvertantly" punched through a cumu while in freefall. Find thermals have fun. Find the updrafts and play with them. But one instance of a single skydiver does not warrant that much concern. I'm more concerned with tracking at the end of every dive than a cumu any day.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[jdthomas 0]

I am a very light TM and when i have taken light passengers during the heat of the summer I have had problems getting down.
i would catch a thermal and gain alit or stay aloft at the current alti.. It was not fun.
Joe

www.greenboxphotography.com

[vpozzoli 0]

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Yes, I was being sarcastic. You took the exception and made it sound like the media's persepctive of that being the rule. Truth is, a lot of us have danced with the cumulous clouds and "use" them for more hang time. Some of us have "inadvertantly" punched through a cumu while in freefall. Find thermals have fun. Find the updrafts and play with them. But one instance of a single skydiver does not warrant that much concern. I'm more concerned with tracking at the end of every dive than a cumu any day.

No, you were being insulting on a personal level.If you can't tell the difference then there is no sense in discussing it further.
From your second post it looks like you don't know the difference between this type of cumulus cloud

http://en.wikipedia.org/wiki/Image:Cumulus_cloud.jpg

and this one (which is actually called a cumulonimbus)

http://scijinks.jpl.nasa.gov/en/educators/gallery/clouds_atmos/cumulonimbus_L.jpg

I doubt you have ever had the chance to 'punch through' one of the latter type. Some have (in reverse) and not all lived to tell the tale. And it's also not a single instance as you erroneously believe.
I suspect cumulonimbus have a much higher chance of forming in the OP's location (equatorial Africa) than in Northern Italy so it may actually pay not to trivialize the risk too much.
As some people are fond of saying it's all fun and games up to the point someone dies.
Cheers,

Vale

[diablopilot 2]

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(it's air rushing in to replace the air that's being sucked up by the cloud),

Clouds don't suck.


Air temps can cause changes in pressure, which can cause masses of air to move, but clouds don't suck.

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You're not as good as you think you are. Seriously.

[vpozzoli 0]

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(it's air rushing in to replace the air that's being sucked up by the cloud),

Clouds don't suck.


Air temps can cause changes in pressure, which can cause masses of air to move, but clouds don't suck.

Go look up 'convection currents' and the physics of water condensation and then you'll understand why some clouds do indeed 'suck'
Hint: you can ask any glider or hang-glider pilot and he'll surely be able to explain it to you.
Cheers,

Vale

[slotperfect 7]

BIGUN & vpozzoli: please take your personal differences to PMs so we can keep the conversation on track with the original subject.

Thanks.

Arrive Safely

John

[AndyBoyd 0]

I've done almost 2000 tandems, many of them on hot days with small passengers. I have got caught in thermals, and it can be an issue on a busy day with students waiting on the ground. I do not claim to understand the science behind thermals, but my experience tought me that there are really only 2 solutions. 1 - spiral like crazy (like another poster says, as much as your passenger can tolerate). 2 - thermals seem to be concentrated in small areas over dark surfaces (i.e. runways or dirt fields), so try to move away from these areas if the spot allows you to do so.

[vpozzoli 0]

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BIGUN & vpozzoli: please take your personal differences to PMs so we can keep the conversation on track with the original subject.

Thanks.

Got it.

Vale

[tombuch 0]

It sounds like you were in a large weather system, and there was probably no way to get away from it, other than increasing your descent speed with a tight spiral. It's also possible you were in a mountain wave on the windward side of the ridge.

I sometimes seek out thermals to increase my hang time and improve vertical separation with other canopies. They are generally small and concentrated, and often build over very specific land features. To get away from them, fly away from the land feature, keeping in mind the thermal will move downwind as it climbs.

I'm also a glider pilot and use that skill set to find thermals. Flying gliders is fun stuff, but skydiving is way better!

Tom Buchanan
Instructor Emeritus
Comm Pilot MSEL,G
Author: JUMP! Skydiving Made Fun and Easy

[diablopilot 2]

You really missed the point.

If clouds "suck" where does the stuff they "suck" go?

Dude, stop trying to act important. It's not impressive.

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You're not as good as you think you are. Seriously.

[crazyboy 0]

Just "another" story ...

http://www.foxnews.com/story/0,2933,252405,00.html

If your parachute fails to open, remember you have the rest of your live to fix it.

[vpozzoli 0]

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You really missed the point.

If clouds "suck" where does the stuff they "suck" go?

Dude, stop trying to act important. It's not impressive.

Are you really saying there are no vertical air currents in a storm cloud? If that is the case you really have no idea what you're talking about.
As for me triying to act important, well I could literally pave roads with the amount of attitude I'm getting from some of you people out of a single post of mine.
I've had enough, I'm out of here. Back to places were the attitude does not 'suck' as much, like Speaker's Corner.

Bye bye,

Vale

[slotperfect 7]

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where does the stuff they "suck" go?

This article explains it pretty well.

There are vertical currents in storm clouds . . . you can watch them build, then anvil at their peak of nastiness right before they dump their load.

Notice in the article the best advice comes at the end of the first paragraph:

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" . . . it is best to avoid thunderstorms as far as possible."

Another case of "prevention is the best medecine."

Arrive Safely

John

[diablopilot 2]

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Are you really saying there are no vertical air currents in a storm cloud?

Never said that, in fact I agreed with it.

Suck is absolutly the wrong term to use when discussing then phenomina. Can you get sucked into a cloud from the side? The top?

And you're the one who waltzed in with attitude. Chill.

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You're not as good as you think you are. Seriously.

[vpozzoli 0]

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Suck is absolutly the wrong term to use when discussing then phenomina. Can you get sucked into a cloud from the side? The top?

This makes absolutely no sense. Apart from the fact that you can get sucked in from the side, you are using your own personal definition of 'suction', which implies that when you suck something through a straw you're not really sucking as the fluid only gets sucked in at the tip, and not from the sides or the top. Makes no sense at all. You must be confusing suction with gravity.

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And you're the one who waltzed in with attitude. Chill.

Spare me the BS. I make one frigging post and all I get right away is gratuitious insults and summary dismissals of my statements without any real discussion.
When I try and discuss I get dismissed because "I haven't been in skydiving long enough". Long enough for what? To know about the wheather and how it relates to fliying?
I think not, sounds more like I need enough jumps just to be able to speak back to the "skygods". Please.
Now I'm really out of here, this is just a big waste of time.

Vale

[bob.dino 0]

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I heard of a woman being taken above 25000' on a paraglider not too long ago but I guess that is not too likely on a parachute?

According to Cookie, it's happened in Australia. Brisbane, 1982.

[tdog 0]

Last summer (under a 1.1 loaded canopy) - I went from 3K deployment to 6K and stayed there.... I was the first out in a 4way, and before I started losing altitude I watched everyone else, including the tandems, land.

It was intentional, I found a thermal and rode it on purpose.

I laugh at the bunch of posts in this thread not about the "suck of clouds", but how bad it "sucked" to be up in a thermal... I guess for TIs interested in volume over quality of customer experience, I guess thermals are a problem.

For me, dialing in a canopy and flying as long as possible is cool... Think of it as dollars per second of airtime. Thermals give you much more.

[toolbox 0]

Riding thermals when alone is great,but I've found that tandem students are more prone to getting sick on those long canopy rides.

[jbanning 0]

Technically the term is reflectance..................Electromagnectic radiation that is stored through the product of absorption by objects on the earth which in turn released which become exitence energy.

simple physics.....lol

[flyhy 0]

hi rhys
we get this sort of crap all the time in Wanaka in the summer when the ground heats up and warm air rises. Unfortunatly these rising air streams appear as randomly as the bubbles when you boil water in a pot, and with most upward drifts you get down drafts as well, and those can be quite nasty especially when you hit them on landing and even though you bury the toggles you don't get much lift. When those differences in air temperature get stronger and stronger there's also chance for sudden strong windgusts (from any direction!) and whirly-whirlies, neither of which you want to have around when landing a parachute. I reckon when the wind conditions get too unpredictable it's best to stop jumping for a while until the winds settle inn/down, maybe wait til later on in the day when the ground starts cooling down a bit.
..if you don't have that option then just let your canopy fly, keep it pressurized and leave yourself outs on landing incase you hit a downdraft or get picked up by a thermal..

hope this helps.

*koni*