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giffnyc

Exit order for tracking groups

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The best laid plans don't always go to plan.



No, and therefore there is no absolute that guarantees that things won't go badly once people have left the aircraft.

That doesn't mean we don't do our best to provide information, direction, and post-jump feedback.

Trackers are rarely a problem for anyone at our DZ. Angle flyers, are a different breed altogether. Because it's the new rage, there are a lot of very low-time people doing it with no clue about how the different angle affects where they are flying. We've had a couple of camps to address this at our DZ, and the information seems to be disseminating very well.

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Ron

******RW large to small
FF large to small
Tracking
WS
AFF
Tandem



I've never seen that order before. Do you know what the thinking is behind it?

You can put the WS last.... But the temptation of the WS to use the students or tandems as swoop toys often gets too great.

As long as the WS jumpers do not fly up the line of flight (and anyone flying a WS should be able to do that) there is no risk.

I just want to throw out there, that there is no real way to stop that short of penalizing people for doing it. Actually, in my opinion, it makes it easier for me to swoop a tandem if you let me get out before them.

Think about it this way - they are going to open at 5k then fly down. That process takes a few minutes at most. If I exit after the tandems I am going to freefall twice as long as they do unless I intentionally dive down after them. That gives the tandems a whole extra 50 seconds to get below an altitude that I am comfortable staying in wingsuit flight.

If I get out before them, that actually brings the time between when they open and when I am going to be around that altitude down. As they freefall I will end up above them for the most part and they will be right there waiting for me.

At least that's the way I would look at it. I personally don't have any desire to wingsuit swoop anyone that doesn't know it's coming.

Edit to add: I also hate being that close to the airport. It makes for some squirrely shit going on with the pattern that we have to fly.
~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

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At our dropzone it usually is
RW
FF
AFF
Tandem
Tracking/Angle flying
WS/Trackingsuits

I think that getting the best exit order already starts at the manifest. It is much easier to organise the exit order if there is one tracking/angle flying group, instead of 4 groups and 3 wingsuit groups. I like Eloy's system where you have to tell manifest if you perform tracking or wingsuit, and they try to avoid the 'too many tracking/ws groups on the load' situation.

When there is just one tracking group at our dropzone they usually exit last, and fly up the line of flight in a straight line. While this does take them further from the DZ, they can use the tail wind to get back to the dropzone (and open a tad higher if needed).

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At our dropzone it usually is
RW
FF
AFF
Tandem
Tracking/Angle flying
WS/Trackingsuits


So...what happens when the angle flyers go down the line of flight (thinking they're 90 to line of flight) and end up in tandem or AFF airspace? (we changed our order specifically because of this)

Or, if they fly 90 to line of flight just before WS, do you have a rule for direction of flight?

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I'm glad this topic has come up. As an S&TA at a very big DZ, we've seen a lot of problems. In fact, this is an even greater freefall puzzle than the exit order debate brought on by the advent of freeflying over a decade ago. The current problem is even more perplexing when you blend tracking, angle, and wingsuit jumps on a single load, and add the fact that a lot of inexperienced jumpers are attracted to this new facet of the sport.

I've been talking to other DZs and will submit a couple of articles to the Safety Section, requesting as well that a new category be created, "Tracking and Angle Flying" or something like that. One will address the exit issue in detail, and the other will consider related problems such as the disproportionate number of freefall collisions and out landings associated with all types of horizontal flying.

In my opinion, there is a good reason that angle flying should almost never exit first, and it's not what you might expect. If you time a lot of angle flying videos, it is clear that the fall rate is essentially the same as freefly. This means that when an angle group exits before belly flyers, between the fall rates and climb out time for the second group, an angle group could be open up to 30 seconds before the following belly group. This is more than enough time for a typical modern canopy (going 50 to 60 feet per second) to fly under the belly group no matter how far off the line of flight the angle flyers go in freefall. I now believe angle flying (aka atmonauti or tracing) should exit in the same order as freeflying, and have a built in angle component that is always 90 degrees to jump run. Which way this component goes must take into account trackers and wing suits on the load.

Tracking is very different from angle flying. Again, timing the videos the freefall time is very similar to belly flying. The big exception is inexperienced trackers, especially on their backs. Therefore, tracking is OK to exit first, but only if led by an experienced tracker and in a direction well away from the line of flight. No low timers (say, sub -500 jumps) should ever be allowed to lead tracking dives, and no jumper of any experience should be allowed to lead on the back unless they are mirrored by an even more experienced tracker flying as co-pilot.

Bryan Burke
S&TA at Skydive Arizona

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Bryan -

I'm the OP - your article on exit order for freefly was exactly the thing that was on my mind when I posed the thread in the first place. I was thinking that we need an update from a source like you that sees a large volume of skydiving and has the patience to look through actual data rather than just make a lot of guesses. I'm really glad your interest is peaked by these problems and looking forward to your articles. I hope you trumpet them loud and clear when they are published.

For my own interest, because I want to see the data, I was thinking of doing a small project of data capture from GPS devices like some of the wing suit flyers carry. I have access to a couple (they're really quite cheap, and folks who spend time on the track with a car or motorcycle have been using them a lot to sync video with GPS data, so readily available) to get some plots from any skydivers here at the Ranch willing to carry them for a couple jumps.

You mention timing videos - would you have any interest in viewing GPS tracks, if we're able to generate some?

Thanks for your continued safety efforts!

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giffnyc

I hope you trumpet them loud and clear when they are published.



have you met Bryan?

(:D:D:D no need to hope, he's the real thing)

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

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Hey gif,
Belly first. Period. I used to allow trackers to go ahead of me after they promised to stay together and track across the wind line bla bla bla. Next thing we know there are trackers under and right in side our space. Why, they said they got disoriented and lost a few of their group.
I found out later they thought they would not make the airport and so modified their run..

I do not let trackers out ahead of my belly group..

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I'd love to see some tracks that show horizontal speeds and distances. Vertical is pretty easy to calculate but horizontal is largely guesswork. My best guess is the horizontal speeds are in the following general area, but I'd love something better than my guess!

Formation Skydiving, 0 to 20 mph due to drift from asymetrical formations or body position. (eg, backsliding)

Freefly: 0 to 30, same causes.

Tracking: 30 - 60 based on my own experiments over our big grid here on the ground of miles and section lines (1/4 mile).

Angle flying: 20 to 40, really getting into guessing here.

Wing suits: 50 to 80.

That's why I contend that angle flyers could very well cover more ground under canopy than in freefall, totally erasing horizontal separation.

And I have to agree with other posters who don't trust trackers to stay clear of the jump run. I once watched a national champion freeflyer lead a group straight up the jump run. In Ampuria, the only tracking dives are ones led by members of Babylon, perhaps due to this but also due to the headaches drop zones get when trackers and WS jumpers land out all the time.

Let us know what the GPS shows!

Bryan

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My first experiments suffered from signal loss during climb to altitude with these small devices, so no data yet. I'm at Nationals this week, but will do some cogitating on keeping the GPS lock on the device and try again after recovering.

Thanks so much for your article - it couldn't be more timely.

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The experienced skydivers (S&Ts) are putting in some serious work to keep us safe -- thank you! I know that it is everyone's job to promote safety, but just a little ignorance can lead to terrible decisions.

My first thought is that opening altitude needs to play a dominant role in the exit order process. Even with great exit separation and no winds, I do not want to be in free-fall through an altitude where there is already an open canopy.

In 8 way formations, jumpers sometimes use staggered deployment altitude which makes perfect sense. Separation in three dimensions instead of only two. The same should apply for the whole load.

If you get out last, you have to pull at x altitude... If you get out before me, I sure hope you are pulling lower. I pull at 3.5K unless I am told to do otherwise.

As far as operating canopy near the jump run, there should be a ceiling altitude in the permitted airspace. If you open at 3.5K, start your flight toward LZ and you are still above 3K, maybe you should have to hang out at a designated holding area as to avoid colliding with someone coming down with a malfunction or sniveling opening.

just my uninformed opinion... take it for what it is worth.
We came here to eat donuts and kick ass, looks like there aren't any donuts.....

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Try sitting back by the door and mounting the GPS on your arm closest to the door. That has worked well for me. If you aren't leaving first, see if you can work it out where you can stay in a position that lets the GPS have a look outside as the others exit.

But yeah, until the FCC allows civilian aircraft to install repeaters, like the military does, you'll lose a lot of GPS runs.

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ut yeah, until the FCC allows civilian aircraft to install repeaters, like the military does, you'll lose a lot of GPS runs.



I have literally hundreds of GPS tracks of over 100 jumpers, with overlays from 23 exits at a time.
In other words, it's quite possible to manage GPS's without repeaters.
GPS is a tool I used to demonstrate why the multiplane wingsuit flight patterns work well here (and have worked well for 3 years).

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I've used a garmin wrist mount for most of this data and never had issues with it acquiring a signal. I've had tracks where my forward was more like 80mph and when maxing out a vampire3 forward speed is as high as 110 mph. When I'm relaxed it's about 80mph.

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giffnyc

My first experiments suffered from signal loss during climb to altitude with these small devices, so no data yet. I'm at Nationals this week, but will do some cogitating on keeping the GPS lock on the device and try again after recovering.

Thanks so much for your article - it couldn't be more timely.



I use a Flysight. It is on and locked before I board the aircraft. I leave it on during the climb. I toggle it off and back on to start a new file about the time we get a two minute warning that the jump run is close. It will reacquire in 2 or 3 seconds and I always get good data. Jumping from a Caravan or an Otter most of the time. The unit is on the back of my helmet.
Instructor quote, “What's weird is that you're older than my dad!”

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I have tracks from Flysights, Droids, wintec, garmin, and other pucks and devices.
Having it on an arm/exposed to the sky is generally very reliable.
*sometimes* sunspot activity can create problems (so can military or other interference).
Paralog's PPC page even has an alert to let you know what's happening in the GPS world.
http://www.paralog.net/ppc/

BASELINE (for Droid only) is another great measuring/logging tool.
I'm a big fan of Flysights mounted on the back of a helmet, on a wrist, or in the wing of a wingsuit. But, they also seem to work well in a chest pocket of a wingsuit.
Regardless of the type of GPS, get a ground fix before boarding.
Reacquire a couple of minutes before exit. We've been turning them on at 8K.
make sure the device isn't modified til after landing (to provide a complete track).

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bryanburke

I'd love to see some tracks that show horizontal speeds and distances. Vertical is pretty easy to calculate but horizontal is largely guesswork. My best guess is the horizontal speeds are in the following general area, but I'd love something better than my guess!

Formation Skydiving, 0 to 20 mph due to drift from asymetrical formations or body position. (eg, backsliding)

Freefly: 0 to 30, same causes.

Tracking: 30 - 60 based on my own experiments over our big grid here on the ground of miles and section lines (1/4 mile).

Angle flying: 20 to 40, really getting into guessing here.

Wing suits: 50 to 80.

That's why I contend that angle flyers could very well cover more ground under canopy than in freefall, totally erasing horizontal separation.

And I have to agree with other posters who don't trust trackers to stay clear of the jump run. I once watched a national champion freeflyer lead a group straight up the jump run. In Ampuria, the only tracking dives are ones led by members of Babylon, perhaps due to this but also due to the headaches drop zones get when trackers and WS jumpers land out all the time.

Let us know what the GPS shows!

Bryan



Here is some data on some small group tracking dives. 2 to 5 jumpers, as I recall. Look in the folder
http://pyrodan.privatedata.com/skydive/group-track-horz-speed/
and you should find a PDF file with the Horz speed graphs. Also in the folder are the KML files that you can view with Google Earth. Right click on the "FreeFall" label on the left side (in Google Earth) and select Elevation Profile to see the graphs. You can select Horz speed, Vert speed, Glide, etc. The distance in miles at the bottom is 3D distance, not ground distance. In a group only one of those jumps went over 80 MPH and that is when we had our back to the wind. Solo for me 90-120 with the wind to my back is not unusual if I am pushing hard.
Instructor quote, “What's weird is that you're older than my dad!”

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