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Wind Tunnel vs Freefall

 


EOCS  (C License)

May 11, 2011, 7:31 AM
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Wind Tunnel vs Freefall Can't Post

Hello,

Ive just done 8 min of wind tunnel training and plan to start AFF courses this Saturday. I think its helps at least let me know that i can arch and not flip on my back. still have some trouble with the legs :P

Im curious the differences between freefall and wind tunnel. I noticed that in the wind tunnel when flying alone i kept starting to spin in one direction, instructor said this was due to the fact that the airs being moved by a fan. But i also noticed that the air was very choppy, not sure if it just felt this way because of the super baggy suit flapping around or if its again the whole propeller thing.

Any insight into the differences is appreciated :)

Thanks


(This post was edited by EOCS on May 11, 2011, 7:32 AM)


davelepka  (D 21448)

May 11, 2011, 7:53 AM
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Re: [EOCS] Wind Tunnel vs Freefall [In reply to] Can't Post

 
Which tunnel was this?

Beyond that, a floppy suit will flop and you will feel it. I'm not sure if the spinning of the fan has anything to do with your spinning, but it's very common for jumpers to turn when first 'let loose' in freefall (or the tunnel). It's just like riding a bike without training wheels, you never know how until you actually do it, and it might take a minute or two to get the hang of it.


AdrianGlave  (D 33419)

May 11, 2011, 8:02 AM
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Re: [EOCS] Wind Tunnel vs Freefall [In reply to] Can't Post

Not suggesting you're asking exactly the same questions - but I started a similar topic a few weeks back.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4104319;page=unread#unread

Some of the replies might be of interest etc


(This post was edited by AdrianGlave on May 11, 2011, 1:46 PM)


hchunter614  (B 30368)

May 11, 2011, 8:09 AM
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Re: [EOCS] Wind Tunnel vs Freefall [In reply to] Can't Post

Usually unintended turns or turning, either in the tunnel or in freefall, is caused by some part of your body not being symetrical. Examples include one elbow lower than the other, dipping a shoulder, one knee being lower or pointed out, one foot being lower or even not pointed like the other. All it takes is a tiny difference and it will cause you to turn. You'll eventually learn how to counteract those imbalances and do it without even thinking about it. No one has perfect symetery, we just learn to compensate.

Enjoy your jump and don't worry about it yet.


EOCS  (C License)

May 11, 2011, 8:45 AM
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Re: [davelepka] Wind Tunnel vs Freefall [In reply to] Can't Post

In reply to:
Which tunnel was this?

Beyond that, a floppy suit will flop and you will feel it. I'm not sure if the spinning of the fan has anything to do with your spinning, but it's very common for jumpers to turn when first 'let loose' in freefall (or the tunnel). It's just like riding a bike without training wheels, you never know how until you actually do it, and it might take a minute or two to get the hang of it.

I think it was this one:
http://www.aerodium-technologies.com/en/products/models/3178/
but it might have been the biggest open air one aswell. it was down in a little gully kinda place, there was no wind that i could tell.


GLIDEANGLE  (D 30292)

May 11, 2011, 1:20 PM
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Re: [EOCS] Wind Tunnel vs Freefall [In reply to] Can't Post

Other differences:

Exit from aircraft is different in that the apparent wind is horizontal rather than vertical.

Tunnel provides better feedback (frame of reference) about our movement.

Tunnel allows very LONG freefall. Real skydiving is VERY time sensitive. We have to pay attention to altitude and getting a canopy overhead at the correct altitude. The tunnel does not have these issues.

Skydiving is more expensive on a per-minute basis.


HAVE FUN!!!


hokierower  (B 36150)

May 11, 2011, 6:34 PM
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Re: [GLIDEANGLE] Wind Tunnel vs Freefall [In reply to] Can't Post

I did AFF jumps 1-6, then 3 weeks ago did an hour of tunnel time, and the weekend after knocked out AFF lvl 7 and then coached jump Lvl 8.

My experience was that the wind tunnel made the freefall maneuvers a breeze. I didn't have to go as crazy as I had on 1-6 mentally preparing for the freefall, I got to spend more time preparing for canopy flight. On the actual jump it was all instinct and afterwards my instructor said that it was not your typical lvl 7 jump.

I found that the tunnel was great for learning, because (a) being altitude aware isn't required (plus & minus), (b) instant feedback on your body inputs (instantly know when something changes), (c) coaching at that exact moment from someone who can observe without have to worry about equipment issues, & (d) long, repeated blocks of time where you can practice multiple things without having to weight long periods of time.

I'm planning a trip back to CO for August timeframe because it's such a great learning tool.


davelepka  (D 21448)

May 11, 2011, 7:43 PM
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Re: [EOCS] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
I think it was this one:
http://www.aerodium-technologies.com/en/products/models/3178/
but it might have been the biggest open air one aswell. it was down in a little gully kinda place, there was no wind that i could tell.

That's an open-air tunnel, and they're a little less smooth and consistant as an enclosed tunnel. Most of the 'training based' tunnel time is conducted in an enclosed tunnel due to being more consistant and having wind 'wall to wall'.

I'm sure your time was helpful, and will make your AFF that much easier. Keep in mind that AFF was develped long before tunnels existed, and is designed to take a guy off the street and put him on freefall later that afternoon. Just go, pay attention to the training, and enjoy yourself.


bluetwo  (C License)

Dec 6, 2011, 10:17 PM
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Re: [davelepka] Wind Tunnel vs Freefall [In reply to] Can't Post

The little bit of tunnel time I got made a HUGE difference, like everybody else I guess. I'm not trying to say it was some mystical thing beyond understanding but at the same time I can't quite explain why it made such a huge difference.

The truth is I didn't feel like I made any real progress in the tunnel and wanted more time. Everybody does, I get it. Yet despite the obvious differences in a smooth indoor setting Vs. wide-open mother nature and all that can happen out there, I still wish I could understand the technical parts better.

I guess people would say get more tunnel time if you want to get better. Normally I say simplify it, by all means, but I would so like to have some decent conversation about tunnels, techniques and how they relate to jumps.


davelepka  (D 21448)

Dec 7, 2011, 5:08 AM
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Re: [bluetwo] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
The truth is I didn't feel like I made any real progress in the tunnel and wanted more time. Everybody does, I get it. Yet despite the obvious differences in a smooth indoor setting Vs. wide-open mother nature and all that can happen out there, I still wish I could understand the technical parts better.

I guess people would say get more tunnel time if you want to get better. Normally I say simplify it, by all means, but I would so like to have some decent conversation about tunnels, techniques and how they relate to jumps.

The tunnel is an excellent trainng tool for freefall. The modern indoor tunnels have such smooth and consistant airflow, they closely match the 'real thing'. Being able to train without the pressure of making an actual jump and being able to fly 5 minutes over the course of a 15 min session greatly accelerates the learning curve.

How they relate to jumps? The tunnel replicates falling striaght down at one speed, the same thing you get in frefall from just after exit until break off. The tunnel will not train you for exits and flying on the hill in subterminal air, and the tunnel will not train you to effectively track, deploy a parachute or fly one to a sage landing. Let's face it, those last three items are of far more importance from a safety/survival standpoint than a good performance freefall.

Think about this, you could leave the plane in the fetal position and hold it all the way to 5000ft, then assume a good arch and deploy a canopy which you fly to a safe landing, you just made a successful jump. Note that you had no performance in freefall, you didn't do anythying, and that's the point. The freefall portion (up to break off) is just a game, it's 'fun time' before you have to save your life. Aside from making sure you don't run into anyone else, the freefall portion of your jump has no meaning in terms of making a safe jump.


beowulf  (C License)

Dec 7, 2011, 6:50 AM
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Re: [davelepka] Wind Tunnel vs Freefall [In reply to] Can't Post

I think tunnel time can help ease anxiety in freefall which will make it easier to deal with everything else that you can't work on in the tunnel. So while it doesn't directly help with exiting, flying on the hill, tracking, deploying or landing it does help indirectly by making the freefall portion less daunting. One of the biggest fears for new skydivers is not being able to control themselves in freefall. The tunnel does help with that.


davelepka  (D 21448)

Dec 7, 2011, 6:59 AM
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Re: [beowulf] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
One of the biggest fears for new skydivers is not being able to control themselves in freefall. The tunnel does help with that.

You make a good point, and in reference to students, it's especially valid. Think about it, part of a safe skydive is deploying a parachute, and doing that properly requires proper body position. Furthermore, at the student level, the freefall is structured to allow for practice of essentail skills like practice pulls, altitude awareness and general stability, so anything you can add to that before the jump is going to be an asset.

In terms of jumpers who can get and remain stable, I agree there might be a degree of extra 'brain power' available if the freefall portion is easier to handle, but I would suggest that more jumpers will tend to focus more on the freefall and less on the other stuff. Once they have invested the time (and money) in the tunnel, and experienced some success during actual freefalls, they might tend to become overly focused on that part of the jump. We all know it can take 1000's of jumps to perfect RW skills, and the focus might shift to honing those skills to a razor sharp edge.

Like I've said before, if tunnel flyers can remember that tunnel time is helpful for freefall, but in terms of skydiving they only have the number of jumps in their logbook, then they should be fine. It's when they let their tunnel time/ tunnel skills lead them to believe they are more of a skydiver then their logbook indicates, then you have problems.


beowulf  (C License)

Dec 7, 2011, 7:15 AM
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Re: [davelepka] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
It's when they let their tunnel time/ tunnel skills lead them to believe they are more of a skydiver then their logbook indicates, then you have problems.

Is there a lot of tunnel flyers that start skydiving and have that type attitude? I am not an AFF instructor so I don't really see that side of skydiving. I have noticed that most of the tunnel rats that I have jumped with generally have canopies sized for their jump numbers and not their tunnel experience. At Skydive Dallas we have a lot of jumpers going to the tunnel and learning new skills, but I don't see them having this type of attitude that you describe. Is this common? I have a little over 20 hours in the tunnel. Mostly working on freeflying and VFS along with a little over 2300 jumps.


(This post was edited by beowulf on Dec 7, 2011, 7:16 AM)


Ron

Dec 7, 2011, 7:45 AM
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Re: [EOCS] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
I noticed that in the wind tunnel when flying alone i kept starting to spin in one direction, instructor said this was due to the fact that the airs being moved by a fan.

Possible, but it should be easy to correct if it was noticed at all.

Quote:
But i also noticed that the air was very choppy, not sure if it just felt this way because of the super baggy suit flapping around or if its again the whole propeller thing.

Both.


Ron

Dec 7, 2011, 7:46 AM
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Re: [beowulf] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
Is there a lot of tunnel flyers that start skydiving and have that type attitude?

I have seen a few of them.


davelepka  (D 21448)

Dec 7, 2011, 8:28 AM
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Re: [beowulf] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
At Skydive Dallas we have a lot of jumpers going to the tunnel and learning new skills, but I don't see them having this type of attitude that you describe. Is this common?

Common, no. A possible downfall of the tunnel, yes.

Look at it this way, it only took one guy not putting on his legstraps to make every wingsuiter take notice put additional focus on their gear checks. Of course, this is nowhere near as dire, but it's the same idea.

The tunnel is a great freefall training tool. Keep in mind it's limitations and that the freefall is only one small part of making a safe jump, and you'll be fine.

You could almost make the connection between success in another sport, and over-confidence in skydiving. We've all met the guy who's an 'expert' snowboarder or motocrosser, and who thinks that those skills make him better able to 'handle things' and that the normal rules of jumping don't apply to him. Tunnel time can produce the same attitude, and probably to a higher degree than other sports due to it's similarity to jumping.

It's hard to remember to be humble and that you only have 50 jumps when you're sitting under canopy after just cranking 18 points on a 4-way.


adagen

Dec 7, 2011, 5:12 PM
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Re: [davelepka] Wind Tunnel vs Freefall [In reply to] Can't Post

While I agree that (in any sport) there are people who assume expertise in one area makes them expert in all areas, there's another way of looking at tunnel experience. When someone has never jumped, the fact of going to the tunnel puts them in contact with people who have jumped, and that gives them an opportunity to find out about everything else that's involved in jumping. In othere words it's an opportunity to find out what they don't know. Anyone with half a brain spending time at the tunnel is going to get curious about what else is involved in jumping.


Austintxflight

Dec 10, 2011, 2:39 PM
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Re: [adagen] Wind Tunnel vs Freefall [In reply to] Can't Post

I have 2 points on this topic.

1. There are absolutes. The tunnel while teaching someone who has 0-100 jumps can give them some overconfidence in their abilities, the vast majority of people who will be using the tunnel during their first 100 jumps, do not progress to a skill level beyond just basic belly flying competency. It is rare that someone can do head down outward facing carving 4 ways in the tunnel and have never jumped from a plane once, and do intend to do it. I would say the only people that fall into this category, are children under the age of 18, or employees of the tunnel. (there are always a few that are not jumpers or have not jumped yet). For the people with a few hundred jumps under their belt, they are experienced enough to understand what tunnel time is for and its benefits, have had enough jumps overall to develop their safety skill set.


2. The one thing I will say about the attitude, part of tunnel jumpers, is that tunnels are not in a bubble.

All the tunnels I have been to have be riddled with skydivers, unless you show up at the time that they have childrens parties, but most of the time its skydivers.

They are always happy to impart words of wisdom and coaching, just like at the DZ, and all this stuff that we are talking about here, gets passed on there as well.

The instructors I've had in the tunnel, even the ones who have never actually made a skydive, but have hundreds of hours flying in the tunnel always seem to the be first to chime in how little they know about it. So even the few that are not jumpers but have hundreds of hours in the tunnel do not come across as arrogant or flippant of the risks, it seems the opposite because there are a million jumpers there telling them just what the risks are.





I am one of these people who does have more tunnel time than freefall time, because there is a tunnel a couple miles down the road from me, and I am a new jumper, and weather and the end of the season prevented more jumping. I've been in the tunnel with jumpers who have had thousands of jumps going in there the first time and I could out "fly" them in the tunnel no problem, but no way in hell am I a better skydiver. The tunnel has differences, in freefall you control the speed, not the guy on the booth. In a 4 way, you cant use the glass to hold your position with your feet like you can in the tunnel. All the fancy running up the glass,holding onto the air returns etc, no relevance to skydiving, it might as well becirque du soleil at that point. The reason I like the tunnel is safety, is I can learn new things safely before practicing them in the sky, in terms of freefall skills (tracking and exits etc withstanding). I can't take a canopy course there though, but I most likely can find the contact of someone who teaches the course during my time at the tunnel.

my 2 cents from a noob


(This post was edited by Austintxflight on Dec 10, 2011, 2:43 PM)


adagen

Dec 10, 2011, 4:38 PM
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Re: [Austintxflight] Wind Tunnel vs Freefall [In reply to] Can't Post

You say there are absolutes, but it is not an absolute that tunnel experience makes someone overconfident. It's also not true that the only non-jumpers with fairly advanced freefall skills and no jumps are either children or tunnel employees.

I'm speaking as someone who had spent 4 years tunnel flying for its own sake before jumping, and, of the people I know who are tunnel flyers but not jumpers, several are neither children not tunnel employees.

For someone who comes to jumping through tunnel experience, the tunnel is an amazing opportunity to see what good freefall skills look like - and to realize just how far you are from that standard since you can see on debrief what you are really doing.

The tunnel is an incredible opportunity to meet people who jump, who are enthusiastic about what they do, who are extremely good jumpers, and who are prepared to share their understanding. My experience was that people were very generous in that respect, whether tunnel instructors or people using the tunnel for training. A long time before I started AFF, it was very clear in my mind that, while I wasn't particularly worried about freefall stabiity, there were big learning areas to do with exit, navigation and canopy handling (sequence, not priority). I also knew that, while I understood how to track, I still had to find out whether I could translate that limited experience into a long straight line track.

The tunnel is also an opportunity to fly with other people and if you do that, then you do have to control your fall speed. If there are two (or more) people with different fall speeds in the tunnel, the driver can't magic up a speed that suits both, it's down to the people in the tunnel to sort that out.

There may well be people who are unjustifiably arrogant about their skills but I would question whether the tunnel can be blamed for that - I suspect the same people would be over estimate their skills after they were lucky enough to land safely, and it doesn't matter whether they are working on bellyflying or have used the tunnel to learn freefly skills.

The tunnel is a tool, and it's useful for one of several of the skills needed for jumping. It doesn't take huge intellectual capacity to work that out and realize that there are things you can't do in the tunnel. People do some amazing stuff in the tunnel, making use of the walls. Nothing wrong with that, tunnel flying is a sport n its own right as well as a way of honing jumping skills.

The tunnel's a tube with air being sucked through it, that's all. It's down to the person how they choose to use it, and how they choose to use their brain to assess their ability level.


davelepka  (D 21448)

Dec 11, 2011, 7:04 AM
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Re: [Austintxflight] Wind Tunnel vs Freefall [In reply to] Can't Post

Quote:
The instructors I've had in the tunnel, even the ones who have never actually made a skydive, but have hundreds of hours flying in the tunnel always seem to the be first to chime in how little they know about it. So even the few that are not jumpers but have hundreds of hours in the tunnel do not come across as arrogant or flippant of the risks, it seems the opposite because there are a million jumpers there telling them just what the risks are.

Thanks for taking the time to state the obvious.

The post that revived the thread was asking about the differences between tunnel time and actual jumps. I don't think the guy wanted to hear that a tunnel is inside and you fly without a rig, and that a skydive is outside and you jump from a plane, he was looking for the more subtle differences.

Take the FJC for example, do they tell you it will be fun, and that you'll jump out and then fly a parachute? Sort of, I guess, but they spend way more time talking about the 'what ifs', the things that could go wrong and what to watch out for. How many people actually have a cutaway on their first jump? How many people are taught to cutaway before their first jump?

Not all tunnel flyers are overconfident once they hit the DZ, we all know this. If you want to know the 'what ifs' of tunnel training for a skydiver, misplaced confidence is one them. It's not the majority of tunnel flyers, but it's something that happens and something to watch out for.

The truth is, if the majority of tunnel flyers created or exhibited a problem when they went to DZ, they wouldn't be going to DZs.


(This post was edited by davelepka on Dec 11, 2011, 8:14 AM)



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