freeflyers or belly flyers out first??

[J_bird 0]

I've been to DZ's where belly flyers are first out of the plane and I've been to DZ's where free flyers get out first, the SIM says slower falling groups get out first. It seems like faster falling groups would have a better chance of catching up to the slower groups this way.

Can anyone explain why its better to do it this way?

[PhreeZone 15]

Search the forums for Freefall drift and specifically for Kallend's simulator.

Vertical seperation is never reliable, only horizontal is.

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[billvon 2,434]

>Can anyone explain why its better to do it this way?

Because when you put the freeflyers out first, they drift TOWARDS the first belly group, resulting in less separation and more close calls. When you put the RWers out first, they drift AWAY from the first freefly group, resulting in more separation. (Assuming jump run is into the wind.)

A longer explanation is attached below. It's been discussed many times before here.

[J_bird 0]

ahhhhh..............makes since now, thanks.

[2shay 0]

I would tell those dz's to screw themselves if they wanted belly groups out last. That just stupid

don't try your bullshit with me!!!

[piisfish 135]

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I would tell those dz's to screw themselves if they wanted belly groups out last. That just stupid

this is if you always drop jumpers with wind from the front. If dropping with tailwind, the situation is changed.

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[billvon 2,434]

>If dropping with tailwind, the situation is changed.

Also, when flying crosswind, different considerations apply.

[Orange1 0]

I'm beginning to think there should be a sticky with "do a search for most popular topics" , off the top of my head these being the AFF vs SL debate and the exit order debate.

Skydiving: wasting fossil fuels just for fun.

[stevo 0]

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Can anyone explain why its better to do it this way?

...because canopy traffic is far less of a problem than exit separation. just check the fatality reports. how hard is it to count to 20? apperently it's so difficult that putting people out in an order that will put them all in the pattern at the same time is the only solution and it's working out great. let's not change a thing.

way to think it through.

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[speedy 0]

Sure, the 20 seconds head start the freeflier has with his Sabre 150 is going make sure he lands before the following belly flier with his Velocity 75. I think not.

You cannot solve problems with canopy traffic by putting people out on top of each other.

Only a few weeks ago at my home DZ the arguement about canopy traffic was put to me by a freeflier. He went against DZ policy and exited 1st as a freefly group. Guess what? for the first time in ages we nearly had a canopy collision between one of the freefliers and a following bellyflier.

Dave

Fallschirmsport Marl

[druvaughn 0]

While visiting a new DZ I questioned why FreeFlyers were put out first. (Assuming jump run into the wind).

The answer, reflects someone else's thoughts posted above...

Most freeflyers fly HP wings and swoop so if they get out first they will have the pattern to themselves to swoop. The argument continued that most belly flyers are jumpers with lower numbers and aren't swooping. The logic is clear isn't it???

Pleaes note that I don't agree with this at all...

Best,
Dru

-
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"Baseball is 90% mental. The other half is physical."

[AFFI 0]

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He went against DZ policy and exited 1st as a freefly group. Guess what? for the first time in ages we nearly had a canopy collision between one of the freefliers and a following bellyflier.

Was any further action taken against said prideful dumbass?

[ZigZagMarquis 8]

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I've been to DZ's where belly flyers are first out of the plane and I've been to DZ's where free flyers get out first, the SIM says slower falling groups get out first. It seems like faster falling groups would have a better chance of catching up to the slower groups this way.

Can anyone explain why its better to do it this way?

I've experienced both too. Most places its pretty much like:

RW groups, big to small, out first.
FF groups, big to small, out next.
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Although I agree with the reasons why its best to be that way, I've been to DZs that put the FF groups out first and then the RW groups. I usually just shake my head and on the inside say "whatever" and then when exiting after the FF groups, just take a few extra seconds seperation .


Anyway, look at it this way, if you go with the RW first and then FF second rule... y'all Freefliers get to sit more toward the front of the plane which is warmer in winter!

[rehmwa 2]

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He went against DZ policy and exited 1st as a freefly group. Guess what? for the first time in ages we nearly had a canopy collision between one of the freefliers and a following bellyflier.

Was any further action taken against said prideful dumbass?

Which dumbasses?

1 - The freeflyer that just plain doesn't understand that the laws of physics also apply in recreational activities. As a result, he's trying to kill everybody else. Or force the entire plane to maybe have to do multiple passes to ensure separation between groups.

2 - Or the belly flyer that also doesn't understand drift and must realize that (if a dumbass gets out that's flying a much higher fall rate position), then to be safe, he needs to significantly increase his delay.

3 - Or the dumbasses in the plane screaming GO GO GO to the belly flyer who really does need extra delay.

...
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

[speedy 0]

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I usually just shake my head and on the inside say "whatever" and then when exiting after the FF groups, just take a few extra seconds seperation .

Try adding to your usual separation time, 4 seconds plus 2 seconds for every 10 kts of upperwinds.
So if you would leave 8 seconds following a belly flier, and the uppers are at 30 kts, when a belly follows the freeflier he would leave 8 + 4 + ( 3 * 2) = 18 seconds.

As you can see, you should be leaving more than a few seconds.

Dave

Fallschirmsport Marl

[winsor 187]

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I usually just shake my head and on the inside say "whatever" and then when exiting after the FF groups, just take a few extra seconds seperation .

Try adding to your usual separation time, 4 seconds plus 2 seconds for every 10 kts of upperwinds.
So if you would leave 8 seconds following a belly flier, and the uppers are at 30 kts, when a belly follows the freeflier he would leave 8 + 4 + ( 3 * 2) = 18 seconds.

As you can see, you should be leaving more than a few seconds.

I don't follow your algorithm.

IIRC, the difference in throw between FF & RW works out to be like 3.5 seconds. This is to say, if a FF group gets out and an RW group gets out 3.5 seconds later, the RW group will be on top of the FF people at opening altitude.

Thus, if you wait 4 seconds before beginning your count, you should be good to go.

Of course, if you stick to the industry standard exit order (ask B. Burke), you avoid these issues in the first place. Complexity tends to work against safety.


Blue skies,

Winsor

[speedy 0]

Yep the forward throw difference is 3.5 and not 4 seconds. It is just easier to count to 4 rather than 3.5
The additional wait time is needed when the jump run is into the wind to adjust for the difference in freefall drift. It is only needed if there is wind.
Hence you always need the 3.5 (or 4 secs) plus the 2 seconds for every 10 kts of wind (freefall drift difference).

Dave

Fallschirmsport Marl

[ZigZagMarquis 8]

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I usually just shake my head and on the inside say "whatever" and then when exiting after the FF groups, just take a few extra seconds seperation .

Try adding to your usual separation time, 4 seconds plus 2 seconds for every 10 kts of upperwinds.
So if you would leave 8 seconds following a belly flier, and the uppers are at 30 kts, when a belly follows the freeflier he would leave 8 + 4 + ( 3 * 2) = 18 seconds.

As you can see, you should be leaving more than a few seconds.

Pardon me, but that's what I meant... if I have to exit, doing RW, following a group of Freefliers at a DZ that insists on FF groups out first. While I don't carry my slide rule, protractor, GPS and scientific calculator with me on every jump run, I have done this a few times.


You're point about, if RW has to exit after FF, that a "few more seconds" isn't 2 or 3, but "more" is correct though. Even more reason for RW, large to small groups, then FF, large to small groups, is best, IMO.

[rehmwa 2]

so from this - rule of thumb for RW after FF -

double the delay, then add a few seconds to flick off those screaming GOGOGOGOGOGOGO

then, keep you eyes WIDE open during opening and tracking

better just to exit order - slowest to fastest

I could give a rats about biggest to smallest - I like to send out a small way right on green and then put the big way out - Then you don't have to request an early light just to accommodate the big way's climbout time.

...
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

[speedy 0]

Rehma - all your points are valid - although I calculate an early light always and just tell small ways to count to 10 after green before they exit. Even if they don't, they can still reach the DZ, it's just a bit more difficult.

ZigZagMarquis - I was not advocating FF before RW, but just giving a more solid way to calculate how much more separation is needed for a into the wind droprun. My only concern was that people may believe a "few" seconds more is needed when really it's a lot of seconds.

You can exit in any order safely if you know how. I just wanted to say to ZigZagMarquis how.
As Winsor pointed out earlier, why make things difficult? Put the RW out first and make things easier.

Dave

Fallschirmsport Marl

[kallend 1,648]

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I usually just shake my head and on the inside say "whatever" and then when exiting after the FF groups, just take a few extra seconds seperation .

Try adding to your usual separation time, 4 seconds plus 2 seconds for every 10 kts of upperwinds.
So if you would leave 8 seconds following a belly flier, and the uppers are at 30 kts, when a belly follows the freeflier he would leave 8 + 4 + ( 3 * 2) = 18 seconds.

As you can see, you should be leaving more than a few seconds.

OF COURSE, THIS ASSUMES AN ACCURATE KNOWLEGE OF THE UPPER WINDS.

The advantage of belly first is that it's pretty fail safe since the trajectories of the bellyfliers and headdowners diverge. If FF goes first, the trajectories converge so it's fail unsafe if you make a miscalculation.

...

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

[rehmwa 2]

What's great here is that more and more people are understanding.

A year ago even there would have been vigorous conflict in a thread like this.

...
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

[stevo 0]

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What's great here is that more and more people are understanding.

everybody understands the solution to fix which proplem?

people not being able to count? come on!

multiple passes? BS. about the same total delay between groups needs to be taken with the current exit order(flat-vertical-flat) at perris and elsinore as before(vertical-flat), i'll do the math for you if you want.

exit order/separation and canopy traffic are separate issues but there is a direct correlation between the two, the current exit order is creating more canopy traffic and i think it's easier to teach people how much separation time to give and to fly there canopy off the line of jump run until the next group opens than it is to teach them how to safely fly there canopy in order to avoid collisions. put up a sign in the back of the plane with a chart that tells people how much time to give at different wind speeds.

[ZigZagMarquis 8]

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As Winsor pointed out earlier, why make things difficult? Put the RW out first and make things easier.

And I'm in violent agreement with that.

Its just that I've still happened across a DZ here or there that the X-hundred jump wonders still insist on FF out first because of their faulty logic and I'm equally tired of listening to their arguments. I'll give them enough time if exiting after them as to be no factor.

[stevo 0]

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>Can anyone explain why its better to do it this way?

Because when you put the freeflyers out first, they drift TOWARDS the first belly group, resulting in less separation and more close calls. When you put the RWers out first, they drift AWAY from the first freefly group, resulting in more separation. (Assuming jump run is into the wind.)

A longer explanation is attached below. It's been discussed many times before here.

this statement is a little misleading, the winds that create what we call "frefall drift" do NOT push fast fallers and slow fallers in different directions. fastfallers do not drift the opposite direction of the wind as the above statement may be interpreted. they just drift less downwind.