The "45 degree rule" for exit separation DOES NOT WORK

[chuck411 0]

jump run was into the wind and we seemed to be creeping in a T otter..

Jump run was changed later in the day and 2 passes became the norm that day

Sorry for the delayed response but I had to go eat dinner:)

[AFFI 0]

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Answer my questions. Hurry I gotta go. How do you achieve separation with a jumper on the A/C. Better yet , what do you tell the jumpers exiting behind you? anything? Verbatum please, as if I was newbie jumping out after you.

Well, I rarely have jumpers other than tandem instructors exit behind me.

What we teach in the curriculum I am involved with is first of all the importance of separation, how the airplane progress over the ground is tied to its relationship between the winds aloft, the differences in freefall drift amongst the different disciplines and why we put skydivers of different disciplines out in a certain order. By the time our students graduate there is a good understanding of the dynamics involved.
In general we like to see 8 seconds between groups unless the winds aloft dictate alternate separation. Whenever the airplanes groundspeed calls for it we will make a general call out to adjust X amount of seconds between groups.

Something like that.

So I do not know if this was the verbatim answer you are seeking. I believe that understanding the dynamics involved in safe separation is a process and not so much an event. That is why, even though I personally may or may not believe in a specific method in teaching it, (the importance of exit separation) as long as the seeds are planted and it directs newcomers to the sport toward understanding it and ultimately as long as safe separation occurs is not terribly important to me. Results over method I guess.

Did I say that right?

Mykel AFF-I10
Skydiving Priorities: 1) Open Canopy. 2) Land Safely. 3) Don’t hurt anyone. 4) Repeat…

[chuck411 0]

Well it made sense to me...:)

And I too agree that method is of no matter as long as the out come is safe separation and a basic understanding of how that separation is achieved.

I have always been one to say things like "OK I understand what your are saying or trying to demonstrate but how does what you are saying give us what we want to happen?"

I just like to know why we are doing what we are doing. Not a great thing in the Army but then again I'm not in the Army anymore:)

*Edited for Speeeeeeeling*

[billvon 2,991]

>what do you tell the jumpers exiting behind you?

"Give us ten seconds."

[rehmwa 2]

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DZ where they preached the 45 rule and as I was doing recurrancy training I just did as I was told however....... I gave a FF trio about 18 seconds from the time they left to the time I started my arch:)

45 degree "rule"
FF out first

why do these two things seem to go hand in hand?


(If the otter was "creeping" along - low ground speed, it's likely that 18 seconds was an appropriate delay (exit to exit). And with drift for RW after FF, it might even have been a bit quick).

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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

[rehmwa 2]

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jump run was into the wind and we seemed to be creeping in a T otter..

Jump run was changed later in the day and 2 passes became the norm that day

Sorry for the delayed response but I had to go eat dinner:)

This is odd. If the uppers were really honking like you say, then exit delays can be huge, and all the jumpers and the tandems can still make it back. (wind direction upper vs lower must have been very different to result in odd jumprun directions and multiple passes - of course, this particular DZ is clueless, so it's hard to see if they had a good reason)

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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

[kallend 2,027]

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How do you tell a jumper how to give you seperation on exit in terms that they will actually understand and do as you intend for them to do? Not saying the 45 degree 'rule' is right. How do you do it Maestro?

So giving the 45 degree thing to a jumper who doesn’t quite get separation yet makes sense?
Why not tell them to count, and train them to do that while on student status?

Or count fleas on the cat – whatever creates separation eh?

How many incidents have occurred over the years that were directly attributable to exit separation?
Perhaps this may be a key inquiry to this whole debate.
How many deaths has it caused?
I don't know...

Answer my questions. Hurry I gotta go. How do you achieve separation with a jumper on the A/C. Better yet , what do you tell the jumpers exiting behind you? anything? Verbatum please, as if I was newbie jumping out after you.

In my experience, most people can estimate 10 seconds more accurately than they can estimate 45 degrees.

I fail to see what the issue is.

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

[jee 0]

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How do you tell a jumper how to give you seperation on exit in terms that they will actually understand and do as you intend for them to do? Not saying the 45 degree 'rule' is right. How do you do it Maestro?

Maestro? Oh...thank you. That being said and me being the maestro that I am I think that question should be left to YOU. Well maybe not you specifically CrazyL but YOU the jumper with a billion jumps. Let's face it, what do I know? I only have 300 jumps and ya'll are not going to listen to me anyway. Without a doubt at the dropzone and even here on dz.com high jumps rule........
I guarantee you if the high jump skydivers set the trend the others are sure to follow.
Training the new jumpers is easy. The real question is how do you train the experienced jumpers?

[CrazyL 0]

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How do you tell a jumper how to give you seperation on exit in terms that they will actually understand and do as you intend for them to do? Not saying the 45 degree 'rule' is right. How do you do it Maestro?

Maestro? Oh...thank you. That being said and me being the maestro that I am I think that question should be left to YOU. Well maybe not you specifically CrazyL but YOU the jumper with a billion jumps. Let's face it, what do I know? I only have 300 jumps and ya'll are not going to listen to me anyway. Without a doubt at the dropzone and even here on dz.com high jumps rule........
I guarantee you if the high jump skydivers set the trend the others are sure to follow.
Training the new jumpers is easy. The real question is how do you train the experienced jumpers?

I'm going to lie about my jump #'s then and put them at 100, so maybe I can get some answers as if i were at 100 jumps like several on lookers here at dz.com. would that be ok? Beyond that, i'd like to think that you are learning from these conversations and about htis thread, how important it is to have adequate seperation between groups. Us high jump # people want you to have a good time and don't kill us in the process. That's part of why I post. Have fun.

[CrazyL 0]

So giving the 45 degree thing to a jumper who doesn’t quite get separation yet makes sense?
Why not tell them to count, and train them to do that while on student status?

Or count fleas on the cat – whatever creates separation eh?

How many incidents have occurred over the years that were directly attributable to exit separation?
Perhaps this may be a key inquiry to this whole debate.
How many deaths has it caused?
I don't know...

[kallend 2,027]

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So giving the 45 degree thing to a jumper who doesn’t quite get separation yet makes sense?
Why not tell them to count, and train them to do that while on student status?

Or count fleas on the cat – whatever creates separation eh?

How many incidents have occurred over the years that were directly attributable to exit separation?
Perhaps this may be a key inquiry to this whole debate.
How many deaths has it caused?
I don't know...

Answer my questions. Hurry I gotta go. How do you achieve separation with a jumper on the A/C. Better yet , what do you tell the jumpers exiting behind you? anything? Verbatum please, as if I was newbie jumping out after you.

In my experience, most people can estimate 10 seconds more accurately than they can estimate 45 degrees.

I fail to see what the issue is.

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Picture this: your at altitude for some reason the exit order switched and you got newbie exiting after you. You can tell that they are scared shitless and have that gut feeling that they are going to exit on too close to you, not giving enough seperation. What are you going to tell/teach them at that moment? Gonna give them a full on 30 minute lesson? Nope cause you only got a few seconds prior to green light. Gonna be like Bill Von (by the way Bill, thanks for your excellent answer, that's easy and quick to relay). Gonna tell them how the 45 degree thing does'nt make since? Or are you gonna supply them with a flea bitten cat and say " count fleas". ( The last one would be fricken hysterical).

Actually, it was originally a dog, not a cat, and I came up with the idea. But you knew that already.

I still think counting to ten is easier than estimating 45 degrees, and what's more, it is not a fundamentally flawed concept.

So you tell the newbie to count slowly to ten (or whatever YOU, the experienced guy, know to be correct).

Telling anyone at any experience level to use a fundamentally flawed method is just plain wrong.

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

[phoenixlpr 0]

How about starting a new thread with a title:"Working method for separation?". Even the name of this should die.

[CrazyL 0]

Agreed. A dog would'nt scratch the newbies eyes out as easy. hehehe. Counting to 10 usually works, so does the 45 degree flawed concept. Counting a jumper could do w/o visually watching the group ahead of them and it would more than likely work. About the visual, just what should a jumper be looking for on the visual part of seperation.

[AFFI 0]

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About the visual, just what should a jumper be looking for on the visual part of seperation.

Checking their spot while counting sounds like a good idea...

Mykel AFF-I10
Skydiving Priorities: 1) Open Canopy. 2) Land Safely. 3) Don’t hurt anyone. 4) Repeat…

[rehmwa 2]

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....... usually works, so does the 45 degree flawed concept. ......

I think you just like to argue for the fun of it.

Let me see if I get your position -

"The 45 degree rule is SO IDIOTIC, that if you teach it to everyone, they will go to the door, become completely confused with the absolute impossibility of such a stupid concept that they might, possibly, if we are lucky, freeze at the door with a stupid vacant expression, for about the correct number of seconds for whatever the winds would indicate, anywhere from no time to as much as a minute between groups - depending, using a real method."

Seems good to me. That vacant look is likely very common on some planes.

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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

[nathaniel 0]

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Like Dracula, it never seems to die.

Why myths persist

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The federal Centers for Disease Control and Prevention recently issued a flier to combat myths about the flu vaccine. It recited various commonly held views and labeled them either "true" or "false." Among those identified as false were statements such as "The side effects are worse than the flu" and "Only older people need flu vaccine."

When University of Michigan social psychologist Norbert Schwarz had volunteers read the CDC flier, however, he found that within 30 minutes, older people misremembered 28 percent of the false statements as true. Three days later, they remembered 40 percent of the myths as factual.

Younger people did better at first, but three days later they made as many errors as older people did after 30 minutes. Most troubling was that people of all ages now felt that the source of their false beliefs was the respected CDC.

The psychological insights yielded by the research, which has been confirmed in a number of peer-reviewed laboratory experiments, have broad implications for public policy. The conventional response to myths and urban legends is to counter bad information with accurate information. But the new psychological studies show that denials and clarifications, for all their intuitive appeal, can paradoxically contribute to the resiliency of popular myths.

...

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Mayo found that rather than deny a false claim, it is better to make a completely new assertion that makes no reference to the original myth. Rather than say, as Sen. Mary Landrieu (D-La.) recently did during a marathon congressional debate, that "Saddam Hussein did not attack the United States; Osama bin Laden did," Mayo said it would be better to say something like, "Osama bin Laden was the only person responsible for the Sept. 11 attacks" -- and not mention Hussein at all.

My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

[CrazyL 0]

So in short :c hecking the spot is definately a good idea and counting to ten slowly is also a good idea and the 45 degree deal should be discarded entirely. That's the good that i've gathered from this post.

[CrazyL 0]

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....... usually works, so does the 45 degree flawed concept. ......

I think you just like to argue for the fun of it.

Let me see if I get your position -

"The 45 degree rule is SO IDIOTIC, that if you teach it to everyone, they will go to the door, become completely confused with the absolute impossibility of such a stupid concept that they might, possibly, if we are lucky, freeze at the door with a stupid vacant expression, for about the correct number of seconds for whatever the winds would indicate, anywhere from no time to as much as a minute between groups - depending, using a real method."

Seems good to me. That vacant look is likely very common on some planes.

Such conviction in your post. You totally missed my position entirely, try again. Do think I believe in the 45 degree deal, argue for fun. You obviously miss my point here. Sure perris is using the 45 degree deal, how 'bout other dz's, what did old timers use to do, what are newbies trained to do, what are others opinions? I know what i do to try to keep others from killing me while skydiving. What do others do, is that a good question or arguement? I use this dz.com as a place to learn and share opinions. Did'nt learn much from your last post.

[AFFI 0]

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the 45 degree deal should be discarded entirely.

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I know what i do to try to keep others from killing me while skydiving.

Takes me back to an earlier inquire concerning the number of fatalities directly attributable to poor exit separation – how many have there been?

Freefall collisions? Canopy collisions? Malfunctions created by close proximity?

Would it be impossible to ascertain such a fact?


Perhaps the salient point that CrazyL is potentially suggesting is that the utilization of the “45 degree” method of teaching and obtaining separation is here to stay - like it, believe in it or otherwise. It is in use across the board by very experienced individuals in the skydiving arena. Is that such a bad thing?
Whether it is correct or not, is there evidence that utilization of such a philosophy has created enough if any fatalities to suggest that we should be so concerned about it? Maybe that is the question we should be asking? Maybe not?

Mykel AFF-I10
Skydiving Priorities: 1) Open Canopy. 2) Land Safely. 3) Don’t hurt anyone. 4) Repeat…

[kallend 2,027]

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the 45 degree deal should be discarded entirely.

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I know what i do to try to keep others from killing me while skydiving.

Takes me back to an earlier inquire concerning the number of fatalities directly attributable to poor exit separation – how many have there been?

Freefall collisions? Canopy collisions? Malfunctions created by close proximity?

Would it be impossible to ascertain such a fact?


Perhaps the salient point that CrazyL is potentially suggesting is that the utilization of the “45 degree” method of teaching and obtaining separation is here to stay - like it, believe in it or otherwise. It is in use across the board by very experienced individuals in the skydiving arena. Is that such a bad thing?
Whether it is correct or not, is there evidence that utilization of such a philosophy has created enough if any fatalities to suggest that we should be so concerned about it? Maybe that is the question we should be asking? Maybe not?

I keep elephants out of my office at night by tearing up two sheets of white paper and scattering the pieces on the floor every evening before I leave. It has never failed.

...

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

[rehmwa 2]

Does Perris really advocate that method?

Knowing so many people there, I really doubt it.

The fact you learned little from the post is due to you. Summary - The 45 has no basis in how people fall and separate in freefall. That's the lesson. That one can still use it to force someone to stop and look and pause for a moment is interesting, and might be better than nothing. But it is no more than just assigning a single delay time that doesn't consider real wind conditions - and, leaving that time arbitrarily up to each jumper.

Look at the winds, check the plane's ground speed on jump run, pick an exit separation that matches. It's not hard to do, it's not hard to learn. SDAZ has the generic rules posted inside the airplane even.

For odd jump run directions and wind conditions, then maybe have someone smarter about it figure it out and get it announced.

The conviction comes from seeing people that use the 45 degree rule falling past me and my friends in freefall because they didn't wait enough on a high uppers wind day. The conviction comes from seeing that happen around my wife and friends. The 45 degree thing would have them exit with the same delay on a low wind day as on a VERY high wind day (relative to the ground winds).

You bet I'm motivated to teach people how to do it right. You bet I'm motivated to eliminate stupid and dangerous old timer 'rules' that don't work.

Get us started on exit order. The 45 degree attitude also leads you wrong on that too.

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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

[rehmwa 2]

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I keep elephants out of my office at night by tearing up two sheets of white paper and scattering the pieces on the floor every evening before I leave. It has never failed.

I'd like to thank you for that. I haven't seen elephant tracks in my office for 3 years now since I've followed your instruction.


Homer - Yup, at least my pay is going towards keeping bears from the city.

Lisa - That's a specious argument

Homer - How do you mean?

Lisa - You see this rock? It keeps tigers away.

Homer - How so?

Lisa - You don't see any tigers, do you?

Homer - Lisa, I'd like to buy your rock.

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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

[rehmwa 2]

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45 degree....is in use across the board by very experienced individuals in the skydiving arena. Is that such a bad thing?

yes, these same "very experienced individuals" also come from the time when the following was done:

1 - believe that vertical separation is a good way to select exit order
2 - spiral down into traffic
3 - think that they should do spirals in order to "get down under the wind" and it will make them hold against high winds better
4 - don't finish their flares now that they have an HP canopy
5 - put high fall rate groups out before low fall rate groups
6 - open right on top of the group before them
7 - don't check their spots
8 - throw out big sashays on final
9 - still show up at the DZ drunk or high
10 - yell GOGOGOGO on an otter load, pile out on top of the group in front of them and still end up "short"
11 - have no idea what booties do for flying ability

more? I'm not kidding - I see this alot. The pioneers did a ton for our sport. But they didn't understand simple physics very well.

Real point - People that used to teach this meant well, even if they are wrong, I can't fault them for trying to do the right thing. BUT, to teach it once they've been informed of drift mechanics, etc, is simply negligent.

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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

[LouDiamond 1]

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The conviction comes from seeing people that use the 45 degree rule falling past me and my friends in freefall because they didn't wait enough on a high uppers wind day. The conviction comes from seeing that happen around my wife and friends. The 45 degree thing would have them exit with the same delay on a low wind day as on a VERY high wind day (relative to the ground winds).

[start rant]Agreed. I still have a hard time grasping how people do not grasp the concept of how and why the 45 rule doesn't work. I also cannot help wonder how a thread such as this one that answers many of the recently asked questions above isn't read through by those asking these very same questions before asking them again.
Read the whole thread if you want answers, chances they are already in the thread. It doesn't matter if your a "newbie" or an "old timer"...RTFT!

I attribute both to laziness and a general lack of attention to detail. It is these two qualities that allow the 45 rule to continue being taught in the sport and also contribute to other (bad)"habits" we encounter routinely in this sport despite people knowing about them. I know for some, they continue to teach the 45 rule to newbies because they find it easier to teach than explaining proper exit order and seperation.

The excuses I have heard are that it overwhelms the person and the typical "they don't need to know that yet". However, the truth of the matter is the person doing the "teaching" is the one who is overwhelmed by their inability to grasp and teach these basic and very important concepts.

Do I think that it will ever cease to be? No, ignorance has historically proven to be hard to defeat. But we can continue to try and educate the newbies and those "seasoned" skydivers open minded enough, in the correct thing(s) to do.[/end rant]


Because I have seen "10 seconds" randomly thrown out there several times already and questions about that time, I have included a excel spreadsheet that breaks what time to use down based on aircraft ground speed, so that everyone on the load gets the needed seperation and can make it back. It's not the first time I've posted it and I know it won't be the last. Download it, print it out, laminate it and tape it next to the door for reference prior to exiting. HINT: In order for this to work, the jumpers must ask the pilot what the ground speed is while on jump run.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[rehmwa 2]

You table assumes no ground winds?

(the 'difference' between ground winds and uppers is what matters, and the assumption that they are in the same direction)

nice table for general use - thanks again

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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