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Tandems jumping first. Safe?

 

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aguila  (B 1009)

Jan 25, 2007, 8:35 AM
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Tandems jumping first. Safe? Can't Post

Hello,

We need to convince our jump-masters that tandems should jump the last. Neither arguments, common sense or incidents have worked.

I myself, during ff was about to hit a tandem when its canopy was open 5 days ago. Please check the link below:

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=2621172;page=1;mh=-1;;sb=post_latest_reply;so=ASC

Please, could you share an official document (USPA, FAI, etc) recommending that tandems should jump the last because they open higher?


speedy

Jan 25, 2007, 8:45 AM
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

If you nearly hit a tandem that jumped before you, the reason would be that you did not leave enough exit separation before you jumped.

There is nothing wrong with tandems going first in the exit order. Sometimes it is helpful.

Edited to add: This might be helpful


(This post was edited by speedy on Jan 25, 2007, 8:48 AM)


Premier billvon  (D 16479)
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Jan 25, 2007, 8:46 AM
Post #3 of 108 (2190 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

>Please, could you share an official document (USPA, FAI, etc)
> recommending that tandems should jump the last because they
> open higher?

USPA recommends that slower-falling groups exit first. I don't think they say much about who should exit where though.

In terms of guaranteeing exit separation, the factors involved are size, odds of sliding and fall rate. Tandems can get out first safely and they can go out last safely - but you have to leave a safe amount of separation. At Rantoul, tandems often get out first because the tandem landing area is _before_ the main landing area during some wind conditions. It's not an issue as long as groups wait long enough.

I assume you would prefer them to exit last due to their higher opening altitude. Keep in mind that even experienced jumpers can have premature deployments; if you almost ran into a tandem you would have almost run into an experienced jumper with a premature opening. Horizontal separation has been (and indeed must be) the primary means of making sure you don't run into people.

That being said, putting tandems out last often makes the most sense because they can make it back from bad spots more easily - and the last people out generally get the worst spots. The additional vertical separation is nice too.


(This post was edited by billvon on Jan 25, 2007, 8:46 AM)


aguila  (B 1009)

Jan 25, 2007, 9:07 AM
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Re: [speedy] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
If you nearly hit a tandem that jumped before you, the reason would be that you did not leave enough exit separation before you jumped.

There is nothing wrong with tandems going first in the exit order. Sometimes it is helpful.

Edited to add: This might be helpful

Right! But we cannot afford waiting 20-30 seconds because our DZ is very small with rivers, a lake, electric wires, etc, all around. And we are usually 17 jumping and you know how pilots hate an unnecesarry second round if you do the right things


aguila  (B 1009)

Jan 25, 2007, 9:13 AM
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Re: [billvon] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:

That being said, putting tandems out last often makes the most sense because they can make it back from bad spots more easily - and the last people out generally get the worst spots. The additional vertical separation is nice too.

Thank you! That makes sense. I will suggest considering a second round when tandems jump first


Premier billvon  (D 16479)
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Jan 25, 2007, 9:17 AM
Post #6 of 108 (2154 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

>But we cannot afford waiting 20-30 seconds because our DZ is very
>small with rivers, a lake, electric wires, etc, all around.

20 seconds is 2000 feet at normal jump run speeds with a 20kt wind, or 1/3 of a mile. If you can't make it back to the DZ from 1/3 of a mile away - something is very wrong. You can put the tandem out half a mile away easily and he'll still make it back. Then you wait 30 seconds and you are directly over the DZ, and the first experienced group gets out.

Or reverse that, so the first group gets out just before the DZ, the last gets out 1/3 of a mile past the DZ, and the tandems get out 3/4 of a mile out. You get the same horizontal separation.

>And we are usually 17 jumping and you know how pilots hate an
> unnecesarry second round if you do the right things.

Well, skydivers hate to open their reserves, cause it costs a lot to get them repacked. But it is better than the alternative.


aguila  (B 1009)

Jan 25, 2007, 9:24 AM
Post #7 of 108 (2141 views)
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Re: [speedy] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
Edited to add: This might be helpful

Great link! Thank you!


aguila  (B 1009)

Jan 25, 2007, 9:43 AM
Post #8 of 108 (2118 views)
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Re: [billvon] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
20 seconds is 2000 feet at normal jump run speeds with a 20kt wind, or 1/3 of a mile. If you can't make it back to the DZ from 1/3 of a mile away - something is very wrong. You can put the tandem out half a mile away easily and he'll still make it back. Then you wait 30 seconds and you are directly over the DZ, and the first experienced group gets out.

Or reverse that, so the first group gets out just before the DZ, the last gets out 1/3 of a mile past the DZ, and the tandems get out 3/4 of a mile out. You get the same horizontal separation.

Thank you! I am glad I asked this question! I will suggest them this alternative. There is a town and a big river just before the end of the runway but it is easier for the tandem to reach the DZ.


piisfish

Jan 25, 2007, 10:25 AM
Post #9 of 108 (2077 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

pull higher, you'll also get back t the DZ.


aguila  (B 1009)

Jan 25, 2007, 10:36 AM
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Re: [piisfish] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
pull higher, you'll also get back t the DZ.

Yeah ... But I have not had problems getting back to the DZ, but my very first jump when it was impossible for me to release the right brake Tongue The problem is the last jumping usually are AFF students.

And I love those extra 5 seconds Cool


riggerrob  (D 14840)

Jan 25, 2007, 11:00 AM
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

I agree with your logic: tandems should exit last.

One time - at a DZ long, long ago and far, far away - I allowed a freefall student and his coach to exit after me. They opened far too close to my tandem! The chief instructor angrily criticized me in public, and I had to "take it" because I was wrong.

At Pitt Meadows, we try to sequence exits to maximize separation. Big groups of belly fliers exit first, then small groups of belly fliers exit second, followed by groups of freefliers (biggest group out first, followed by smallest group, etc.), freefall students are next, followed by tandems, with wingsuiters out last.
Asking for a second pass annoys air traffic controllers, Air Canada, West Jet, Harmony Airways, United Air Lines, Lufthansa, etc. ... so we rarely ask for a second pass.
When the spot is too long, I just land between the runways and wait for a truck to pick me up.


speedy

Jan 25, 2007, 12:23 PM
Post #12 of 108 (2007 views)
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Re: [riggerrob] Tandems jumping first. Safe? [In reply to] Can't Post

Quote:
I agree with your logic: tandems should exit last.
On a upwind drop run, assuming the landing area is the same for all on the drop, I would also agree.
But, someone might find another good reason to put Tandems out first.

It is all about knowing the issues concerning exit separation. Why does the largest RW group go first? If you don't know why, you can't plan the drop run right.

When you think about it, maybe the largest freefly group first after the RW is not the best option in some cases. Maybe a smaller FF group and then the larger is better.


chrismgtis  (B 32561)

Jan 25, 2007, 12:32 PM
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Re: [billvon] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
Well, skydivers hate to open their reserves, cause it costs a lot to get them repacked. But it is better than the alternative.

Not to mention the fact that they will probably never find their main and that is one hell of an expense. Not saying you should ever think about that when it comes time to use your reserve though.


aguila  (B 1009)

Jan 25, 2007, 1:41 PM
Post #14 of 108 (1966 views)
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Re: [riggerrob] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
At Pitt Meadows, we try to sequence exits to maximize separation. Big groups of belly fliers exit first, then small groups of belly fliers exit second, followed by groups of freefliers (biggest group out first, followed by smallest group, etc.), freefall students are next, followed by tandems, with wingsuiters out last.

Thank you! IMHO, that should be the default exit sequence


aguila  (B 1009)

Jan 25, 2007, 1:51 PM
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Re: [speedy] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
But, someone might find another good reason to put Tandems out first.

Please, could you mention a few?

I have seen they do it because they want to land soon so that they get enough room to pack and be ready for the next ride Unimpressed


speedy

Jan 25, 2007, 2:13 PM
Post #16 of 108 (1945 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

Reason 1. What billvon said, landing area is different.
Reason 2. Cross wind drop run. The first and last being high pullers can get back from a longer spot.
Reason 3. Tandems go out lower so as to get back for the next load. The rest go up to full altitude and jump. Depending on the climb rate and how the drop is organised this can be ok.

But the reasons why don't matter. What matters is the the exit separation is correct and the spot is correct. It does not matter how much the go around costs, if you are not given the opertunity to exit when the spot is right, you should make a go around.
The key to the problem is knowing where the spot is.


aguila  (B 1009)

Jan 25, 2007, 3:32 PM
Post #17 of 108 (1914 views)
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Re: [speedy] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
Reason 1. What billvon said, landing area is different.
Reason 2. Cross wind drop run. The first and last being high pullers can get back from a longer spot.
Reason 3. Tandems go out lower so as to get back for the next load. The rest go up to full altitude and jump. Depending on the climb rate and how the drop is organised this can be ok.

But the reasons why don't matter. What matters is the the exit separation is correct and the spot is correct. It does not matter how much the go around costs, if you are not given the opertunity to exit when the spot is right, you should make a go around.
The key to the problem is knowing where the spot is.

You said: "But, someone might find another good reason to put Tandems out first"

The three reasons you mentioned are not reasons to put a tandem first. They are just environments where you can put a tandem first without affecting safety but you could also put the tandem last with better results.

Why I say "with better results"? Because we all now the wind direction changes, so do the landing areas and climb rates. Spotting is not always good. I have seen tandem students who refused to jump.

Put it in other words: Are there any valid reasons that make it a must to put tandems first?


Premier billvon  (D 16479)
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Jan 25, 2007, 4:15 PM
Post #18 of 108 (1901 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

>Are there any valid reasons that make it a must to put tandems first?

At Rantoul, the tandem landing area is to the west of the main landing area. During W-E jump runs, if tandems got out last, they would have to cross the main landing area at moderate altitudes (3000-4000 feet) as the next load was dropping. This isn't too safe. Some possible solutions to this are:

1) Move the tandem landing area. Not really possible in this case; that would put them either on the runway or on the far side of the runway, where aircraft were turning after takeoff/landing (and where there was no easy way to get whuffos to/from.)

2) Reverse the jump run. This is doable PROVIDED you can get people out rapidly enough; some days would have required 3-4 seconds between groups to get everyone out, and often jumpers cannot check for traffic/line up/give the count/go in that short a time. Which means they do not get to jump; there are rarely go-arounds at Rantoul due to traffic.

A third option is, of course, to put tandems out first. It works well _provided_ people leave sufficient room. But for most operations, tandems out last works a bit better because they can just plain get out later than anyone else.


kelpdiver  (B 7)

Jan 25, 2007, 5:07 PM
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
In reply to:
Reason 3. Tandems go out lower so as to get back for the next load. The rest go up to full altitude and jump. Depending on the climb rate and how the drop is organised this can be ok.
Put it in other words: Are there any valid reasons that make it a must to put tandems first?

If the tandems only paid to go to 9,500. (some DZs offer this at a sale price and then try to upsell) The plane dumps em and continues onto 13k. Or 15k for another place I visit.

Can't think of any reason more valid than that.

Someone else already said a DZ has the LZ for tandems short of the main LZ.


aguila  (B 1009)

Jan 25, 2007, 6:57 PM
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Re: [billvon] Tandems jumping first. Safe? [In reply to] Can't Post

Thanks for the input. It seems it is safer the tandems exit last.

If they insist on exit first the following jumper must wait at least 15 seconds, even more if there are clouds around, when jumping from a not too fast plane, no matter how unpopular s/he becomes.

Better safe than sorry! Smile


speedy

Jan 25, 2007, 11:56 PM
Post #21 of 108 (1819 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

Quote:
must wait at least 15 seconds, even more if there are clouds around,

It appears to me that you do not understand the factors involved in maintaining safe exit seperation.

John Kallend has an excellent powerpoint presentation concerning this subject. Here is a direct link to it. Download it and read it carefully.

P.S Hope you don't mind the direct link John.


ps5601  (D 100131)

Jan 26, 2007, 5:19 AM
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Re: [speedy] Tandems jumping first. Safe? [In reply to] Can't Post

I know that at Empuria in Spain the tandems always exit first. However the jump run is always in the same direction too, from the sea, over the town and then over the DZ. High opening tandems can open over the town and make it back easier than the lower opening jumpers.

That being said, putting your largest group out first generally has many more advantages. They can do their long climb out a little early and leave at the correct time with out using "jump run time". Other jumps in the plane can also act as ballast to counter the high weight in the door of the large group, and large groups often fall slower than solos etc (although not always).


aguila  (B 1009)

Jan 26, 2007, 7:20 AM
Post #23 of 108 (1770 views)
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Re: [speedy] Tandems jumping first. Safe? [In reply to] Can't Post

In reply to:
Quote:
must wait at least 15 seconds, even more if there are clouds around,

It appears to me that you do not understand the factors involved in maintaining safe exit seperation.

My concern is about safety when tandems exit first. From this thread we find that is always safer tandems exit last followed by people wearing wingsuits. No exceptions yet.

There are a few specific environments when it might be almost as safe tandems exit first, but as conditions easily change after taking off a Rule of Thumb is TANDEMS SHOULD EXIT LAST followed by jumpers using wingsuits.

The only thing skydivers can be sure of is we are falling down. Every other thing can change. So, in case Tandems insist on exit first they are risking themselves and other skydivers unless some exceptional conditions be met.

As exceptional conditions are not a rule, IMHO, having been to close to get injured , even die because a tandem jumped first, I prefer allow more separation. Maybe a second pass would be needed but that would be the tandem pilots fault


OnYourBack  (D 25190)

Jan 26, 2007, 8:04 AM
Post #24 of 108 (1758 views)
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

As a general rule sure, tandems should go later. However, exit order had absolutely nothing to do with you almost getting hurt. You didn't allow enough seperation.


kelpdiver  (B 7)

Jan 26, 2007, 10:21 AM
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Re: [aguila] Tandems jumping first. Safe? [In reply to] Can't Post

Aguila's profile:
Occupation: Physician

(Big shocker, ay?)

dude, people are trying to give you explanations and you're reading only the bits that fit into your frame of reference.


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