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# Tonysuits can fly up!

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Let's explain this in a way that even non-believers can understand. Thermals can get stronger then 10 m/s+ which is equal to about 22mph. Say he flared his suit out to 15mph (easily doable coming out of a slight dive on the bigger suits.) Do the math and you can see how climbs (with the aid of big thermals) are entirely possible, as the video demonstrates.

Air rising at 22 mph doesn't produce a force that will elevate a wingsuiter at 22 mph. If air were as dense as water you would be closer to being accurate.
Sometimes you eat the bear..............

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air is considered incompressible at subsonic speeds. (hint the 22mph does not have to overcome the force of the wingsuiter accelerating towards the earth the w/s has already done that). their view is valid. if the vertical component of the airpeed is 15mph and i subtract 22mph i get -7mph, everything else in the equasion is irrelevant.

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air is considered incompressible at subsonic speeds

Am I glad my scuba tank doesn't know that!

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There are a lot of sloppy conclusions in this thread being drawn from dubious information but that's par for the course with some of the posters. They don't care about the reality it's just more publicity and keeping the brand at the top of the page, for some of them it's their job.

Hot air indeed!

Next they'll be all over the internet claiming that their suit had the fasted time at the base race, or has a glide ratio of 3.5:1 .... oh wait ...

(Everyone Stop Posting Bullshit Claims) TM

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The published specs for GPS receivers give position accuracy on the order of 2 metres

even in the best of conditions with a lock on 12 satellites, this is hardly EVER the case. just saying..
“Some may never live, but the crazy never die.”
-Hunter S. Thompson
"No. Try not. Do... or do not. There is no try."
-Yoda

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Actually it seems to be possible - even without extra lift!

I was reading this thread while judging the 1st speed round of Wings over Gransee 2011 so I got curious and looked closer at both Oliver Furrers and Helmut Tackes' tracks. Both accomplished fallrates below 10mph while flaring after the speed run so I challenged them to achieve climb during flaring in their second speed round.

Helmut landed and presented an astonishing 3mph fallrate during his flare, but Oliver completely knocked me off my feet: He seems to have achieved climb for 4 secs during his flare, with a max. climb rate of 11km/h!

Chart and raw GPS data attached for review with his permission, climb starts at 11:00:44.20Z in the raw data.

Klaus
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Probably a better comparison would be leaving a Sky Van at high speed and on exit popping up above the aircraft. How many people on this board have done this? I know I have. What about people leaving the plane and hitting the tail? Is this a phenomena you believe impossible?

This is a nice comparison that shows you really should dive into the actual physics a bit more before making these kind of claims.
There are quite a few differences between a flare from normal flight, and an exit from a moving object (aircraft)

The initial velocity (downward) when doing a highspeed exit from an airplane is zero. Meaning the jumper doesnt first have to pull out of his normal flying speed, to get his downward speed down to zero so he can transfer the energy (the full airspeed the airplane is doing) into upward flying.

Around 30 mph is a sustainable flying speed for a big wingsuit, but to get up to the speeds needed to actually have enough energy built op to flare with that power, the downward speeds will be more around 150 mph. And the diving speeds used to get flare speeds down into the 0 mph range are WAY past what we're seeing in Matts video.

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You guys are right, GPS data is not always accurate

The tracks shown by Matt show a lot of sharp angles, meaning missing waypoints.
The track I pointed to earlyer from his Eiger jump shows a climb directly after exit, but also allong the track has several points that are higher than the previous one. Meaning (according to the GPS) he had several moments where he went up.

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If you had told me we would be doing the things we are doing now 10 years ago I would have said, "your on crack, that's impossible" and you know what's funny, i would have been very, very wrong :)

Lets hope that here it takes you less than 10 years to figure out you were wrong
JC
FlyLikeBrick
I'm an Athlete?

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Diving for how long at what GR? unlikely to be doing the same close to the ground?

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Thats really cool...
Though many people claim to be climbing, Its only in these insane highspeed dives and mega flares we actually see the results.

I think Visa was the first one to also register (I believe) an 8mph climb after a similar dive about a year and a half ago. And now seeing Helmut and Oliver do the same, its quite cool. But its also quite obvious the diving and flaring they are doing there is so much faster and 10 times more agressive than what we're seeing in Matts video.
JC
FlyLikeBrick
I'm an Athlete?

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Luke,

look at the attached chart. Or load the attached track into Paralog and look for yourself.

Klaus
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I'm travelling for the next while but you get the point.

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air is considered incompressible at subsonic speeds. (hint the 22mph does not have to overcome the force of the wingsuiter accelerating towards the earth the w/s has already done that). their view is valid. if the vertical component of the airpeed is 15mph and i subtract 22mph i get -7mph, everything else in the equasion is irrelevant.

Well that sure lets the air out of my tires!
Sometimes you eat the bear..............

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I couldn't make it past the crappy music.

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I've attached another plot focussing on Oliver's flare. The vertical speed here comes directly from the CSV file, so it is largely independent of the elevation. The error bars for speed and elevation come from the speed accuracy and vertical accuracy, respectively, reported by the GPS receiver.

The discontinuity just before point #330 caught my attention, and I think there may be an explanation that will be helpful for others trying to get this kind of data.

Most GPS receivers rely on an internal model in order to reduce the noise inherent in their measurements. This model describes the kind of motion the unit is expecting. Anything that doesn't fit the model is essentially written off as noise. The more restrictive this model is, the lower the noise becomes. However, if you choose a model that is too restrictive, then some of your actual motion may wind up in the "noise" pile.

By default, FlySight uses a model called "Airborne with < 1 G acceleration". In most cases, this works beautifully for wingsuit flight. However, it doesn't work quite as well, e.g., for swoopers. We noticed at one point that swoop tracks were consistently going below the ground, then recovering upward. While planing out, they were experiencing more than 1 G acceleration, but the model had "smoothed" the track to keep acceleration within the expected limits. Changing the model to "Airborne with < 2 G acceleration" corrected the problem.

In the attached plot, it looks to me like acceleration was nearing the 1 G limit just before the discontinuity, which makes me think the discontinuity itself may be a sort of correction, and makes it harder to say exactly what's going on with the data just after it.

For anyone using a FlySight to log this sort of jump, where an aggressive flare is used: Be sure to change your model at least to "Airborne with < 2 G acceleration". This way, you'll stay clear of the limits of the model, and avoid glitches.

Michael

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air is considered incompressible at subsonic speeds

Am I glad my scuba tank doesn't know that!

What he sould have said is unconfined air in not compressible at subsonic speeds... Rather then compressing it travels around the object. Really means nothing here though. Not like anyone thought the wingsuiter was squishing the air!!!

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I've been paragliding for several years and do understand those forces. I really don't believe they are enough to give a wingsuit lift. My 16m speed/acro wing doesn't get any sort of significant lift from thermals so...

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Let's explain this in a way that even non-believers can understand. Thermals can get stronger then 10 m/s+ which is equal to about 22mph. Say he flared his suit out to 15mph (easily doable coming out of a slight dive on the bigger suits.) Do the math and you can see how climbs (with the aid of big thermals) are entirely possible, as the video demonstrates.

Air rising at 22 mph doesn't produce a force that will elevate a wingsuiter at 22 mph. If air were as dense as water you would be closer to being accurate.

Well I don't know much about wingsuits and base jumping, but I do know that thermals and slope updrafts can be very powerful.

If it can lift aircraft with higher wing loadings than wingsuits, on a day with a lot of convection and unstable air I have no doubt it can reduce the fallrate of a wingsuit to zero or to a climb for the time it flies trough the updraft.

LetsGoOutside: if your 16m wing doesn't get any lift from thermals, believe me, it's that the thermals are not there or not strong enough.

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Michael,

thanks for looking into this!

> Changing the model to "Airborne with < 2 G acceleration" corrected the problem.

Maybe this model should then be the default when a new config.txt is created?

I will PM/post Helmut's raw data of the 3mph fall rate as well, maybe you could analyze it too?

Klaus

Edit: Chart and raw data attached
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I will PM/post Helmut's raw data of the 3mph fall rate as well, maybe you could analyze it too?

I've attached the analysis of Helmut's track. Alas, it has similar discontinuities. I would be very interested to see the same test repeated with the units set to the 2 G model, to confirm that the 1 G model is the cause.

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> Changing the model to "Airborne with < 2 G acceleration" corrected the problem.

Maybe this model should then be the default when a new config.txt is created?

Perhaps. I haven't done this yet because using a more inclusive model (i.e., using the 2 G model instead of the 1 G model) will result in increased noise in the data. Provided you're flying within its parameters, you should get more accurate data using the 1 G model.

That said, it's possible that the difference in noise is negligible, in which case the 2 G model might be a better default. If you're still flying, I'd love to see a track using the 2 G model for comparison.

Michael

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Thanks, Michael!

Unfortunately, the event is over oálready, but maybe we can get the two guys to repeat the experiment with the other settings. Oliver at least has a FS and I could give mine to Helmut for this.

Looking at your plot of the data and trying to guess how a Kalman filter would treat data which exceeds a maximum accaleration I tend to believe that only the data just before the glitches is inaccurate as the filter tries to limit the change in speed and altitude to 1g. At some point, when the accumulated error reaches a certain threshold, my guess would be the filter gives up and 'jumps' to the values as reported by the sensor. The accuracy of the sensor data (which seems to be quite good) would play a role in how big the accumulated error would be allowed to get.

Just guessing, maybe uBlox can help ;-)
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Thanks, Michael!

Unfortunately, the event is over oálready, but maybe we can get the two guys to repeat the experiment with the other settings. Oliver at least has a FS and I could give mine to Helmut for this.

Looking at your plot of the data and trying to guess how a Kalman filter would treat data which exceeds a maximum accaleration I tend to believe that only the data just before the glitches is inaccurate as the filter tries to limit the change in speed and altitude to 1g. At some point, when the accumulated error reaches a certain threshold, my guess would be the filter gives up and 'jumps' to the values as reported by the sensor. The accuracy of the sensor data (which seems to be quite good) would play a role in how big the accumulated error would be allowed to get.

Just guessing, maybe uBlox can help ;-)

I would have guessed the same as you. I'll send an email to u-blox to inquire.

Michael

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air is considered incompressible at subsonic speeds

Am I glad my scuba tank doesn't know that!

Really means nothing here though. Not like anyone thought the wingsuiter was squishing the air!!!

um the guy who was comparing air to water, results for this case would be the same regardless of the fluid.

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Dunno about positive rate of climb, but the soundtrack is positively annoying.
...

The only sure way to survive a canopy collision is not to have one.

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It looks like I misinterpreted the jumps in the data. What's actually happened here is that the speed accuracy fell below the threshold specified in the configuration file, so the FlySight stopped logging. Looking at the raw data, a few seconds are lost inside each break, but because of the way I was plotting the data, this showed up as a sudden jump instead of a break in the plot.

So, all of the data for these two jumps seems to be valid.

To avoid the problem in the future, the speed accuracy threshold could be increased in the configuration file. However, this would result in more erroneous points being logged, e.g., just before exit. The speed accuracy threshold was introduced to prevent false "exits" when importing data into Paralog. Considering that data could be lost irretrievably because of a low threshold, I wonder if it might be better to handle this filtering when the data is imported into Paralog, rather than preventing the data from being logged at all.

Looking at Helmut's track again, the elevation appears to go up, but the size of the error bars, combined with the fact that the velocity never quite makes it to zero, make me think he was close, but not quite there.

Looking at Oliver's jump, again we see the rising elevation--still with fairly large error bars. However, the vertical speed drops below zero by an amount larger than the estimated speed error. Ideally, I'd like to see a little more room above the error bar, just to be sure, but I would say based on this data that Oliver flew upward for about one second.

Michael

Edit: I've attached updated plots showing the gaps in logging more clearly.

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It's nice to see what happens when an engineer is faced with a challenging problem ;-) Thanks for investigating further!

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I wonder if it might be better to handle this filtering when the data is imported into Paralog, rather than preventing the data from being logged at all.

Let's take this to email.

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Ideally, I'd like to see a little more room above the error bar, just to be sure, but I would say based on this data that Oliver flew upward for about one second.

Nice!

I think we need to add a new category to PPC: Longest or fastest climb ;-)
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Not saying it's impossible, just saying it doesn't look like it here...

It's shame that has to be focus of a video that can just stand on its own as something very cool.

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