45 degree rule

[yeehaa 0]

What is the 45 degree rule????

Life does not cease to be funny when people die any more than it ceases to be serious when people laugh.
George Bernard Shaw

[weegegirl 2]

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=951741#951741

[bmcd308 0]

It is a method of determining proper exit separation that does not work.

You look out the door at the group before yours, and when they have fallen behind the plane to a 45 degree angle, there is enough separation for your group to go.

It is not a preferred method of determining separation. There have been lots of exit separation threads in Safety and Training.

----------------------------------
www.jumpelvis.com

[ChrisL 2]

NOOOOOOOO!!!!!

__

My mighty steed

[mccordia 74]

It's a 'rule' that replaces counting in between exits according to some people. Basicly from what I learnt here on dz.com it means this...

The 45 degree rule:
The angle at which someones fist will hit your head after you nearly miss an opening canopy from someone who jumped before you (when using 'the 45 degree rule' instead of just counting a few seconds for decent seperation between exits)

Question:
If you look out the door and see someone that exited a second before you, about 10 meters behind/below the plane, at a 45 degree angle...would you jump?

Try this for a better answer>

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=954278

JC
FlyLikeBrick
I'm an Athlete?

[billvon 3,075]

>What is the 45 degree rule????

It is something that people do to try to ensure exit separation; they wait until they see a 45 degree angle and then they go. It does not work, but it has persisted because people like simple solutions even when they have no basis in fact.

[JohnMitchell 16]

It is something you should ignore, and don't listen to anything else that person has to say, either.

[quade 4]

The 45 degree rule.

The length of the 45 degree angle, from corner to corner of a square, is 1.41 times the length of the sides.

Did I get it right? Did I win a stuffed pony?

quade -
The World's Most Boring Skydiver

[skr 1]

> What is the 45 degree rule????

I think it's based on the plausible-at-first-glance
idea that when the group in front of you has fallen
far enough behind the plane it's OK to go.

But:

1 - they never actually get to 45 degrees so it's
a poor name

2 - it misleads you to think about some angle when
it's really horizontal separation that you're after

3 - if there are uppers it doesn't work

Down at the bottom of

http://indra.net/~bdaniels/ftw/index.html

is a collection of people's writing about separation.


It reflects the fact that people would rather have
a simple sound bite answer than a more complicated
answer that actually addresses the situation.

That may be unfair but I'm getting disgruntled by
this trend that I'm seeing:

- sound bite butt slide instead of PLF

- sound bite 45 degree rule instead of better answers

- sound bite follow first person down instead of some
better procedure

- sound bite down size instead of deciding whether
you even want to and then getting some substantial
training


I think part of the reason is that the skydiving industry
is now driven by simple corporate bottom line and
letting other important factors slide, plus USPA has
done almost nothing about any of this.

If you want to see how much progress we've made
see USPA's response to separation down at the bottom
of that URL.


So, I hope I don't regret saying all this stuff, but I really
don't like this sound bite trend.

Skr

[yeehaa 0]

thanks for the info everyone. I just saw references to it on some signatures, have never actually heard it mentioned at my dz. which Im thinking is definitely a good thing......

Life does not cease to be funny when people die any more than it ceases to be serious when people laugh.
George Bernard Shaw

[tattoojeff 0]

: NOOOOOOOO!!!!!
.
.
lmao

[lummy 4]

the thing about the 45 degree rule that I don't get is that it has been shown by video that a jumper typically will never get to 45 degrees. With that in mind, it stands to reason that someone in the plane would see that the jumpers ahead are never going to cross the 45 degree line.
Why is it that people swear by it and use it when the proof is right in front of them?

I promise not to TP Davis under canopy.. I promise not to TP Davis under canopy.. eat sushi, get smoochieTTK#1

[kallend 2,106]

Quote

the thing about the 45 degree rule that I don't get is that it has been shown by video that a jumper typically will never get to 45 degrees. With that in mind, it stands to reason that someone in the plane would see that the jumpers ahead are never going to cross the 45 degree line.
Why is it that people swear by it and use it when the proof is right in front of them?

Er - people believe lots of things without proof, or contrary to all evidence.

...

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

[winsor 236]

Quote

the thing about the 45 degree rule that I don't get is that it has been shown by video that a jumper typically will never get to 45 degrees. With that in mind, it stands to reason that someone in the plane would see that the jumpers ahead are never going to cross the 45 degree line.
Why is it that people swear by it and use it when the proof is right in front of them?

The 45 degree rule works great as long as there is not an inversion, we are using Fahrenheit, and the temperature is low enough (like a maximum of 35 degrees Fahrenheit) at exit altitude.

If you watch the previous group and wait until they are in 45 degree (Fahrenheit) air before your group exits, you should be just fine.

Estimating the temperature of the air through which the previous group is falling is an art that takes years to master.

Of course, with modern electronics available, I'm sure someone could come up with a temperature transmitter that could provide the necessary information to make this the method of choice throughout the sport.

In the meantime, however, using one of the other methods that keep groups centered many hundreds of feet apart at opening altitude will have to suffice.


Blue skies,

Winsor

[karlm 0]

Our DZ (www.jsc.co.za) here in 'ol South Africa has given the 45 rule the boot a long time a go, we ahve moved to what I would say is a much better and more accurate way to ensure good separation between groups.

We have a chart in the back of our Porter, with four levels on it Low, Medium, High & Very High, which indicates the wind speed at altitude, the pilot will on a time to time basis, get a jumper to write either a L, M ,H or VH on the chart, these correspond to timings between groups.

The time between exits is based on the ground speed on the aircraft and the distance covered according to the wind speed at altitude. Exit times are between 8 to 20 seconds between grounds.

We have found this to work well for us at our DZ.

Will post a jpg of it if I can find it on video.

Better never to have met you in my dream than to wake and reach for hands that are not there.

[skr 1]

>We have a chart in the back of our Porter

I think this is a good direction to go.

Down at the bottom of

http://indra.net/~bdaniels/ftw/index.html

there is a section called "Upper Winds and Exit
Separation" and in that section there are a couple
of articles about this idea:

2004 - Dealing with Uppers - part 1

and

2004 - Courtney Frasch - Exit Separation Spreadsheet

When this was brought up to the manager of the
closest local DZ he thought it was a bad idea
and wouldn't do it.

I don't understand the resistance to addressing
this question but it's been going on for a long time.

Maybe if enough of the rest of the world moves on
this the skydiving industry here in the US will follow
along and PCA, I mean USPA, will come along too.

I know I should maintain my serenity on this and be
ever cheerful and helpful, but every weekend I encounter
people following me out who, if they've been taught
anything at all, answer with "wait 5 seconds and go"
or "wait for 45 degrees and go" and the loading area
with the props turning isn't the place to go into it.


Patience ... om om om ... this is a test ... om om om ...
of how well you can maintain ... om om om ... in the
face of distraction ... om om om ... :-) :-)

Skr

[yeehaa 0]

thanks for posting that link skr I've printed out the spreadsheet and will take it in to my DZ. Hopefully I will be allowed to put it next to the door of our turbine. Often the loads are mostly inexperienced jumpers with less than 100 jumps so this will help us to determine how many seconds we need to count before exiting the plane.

thanks again!!

Life does not cease to be funny when people die any more than it ceases to be serious when people laugh.
George Bernard Shaw

[tbrown 26]

Quote

What is the 45 degree rule????

It's the mistaken belief that you can play Russian Roulette with a .45 automatic if you only put one round in the magazine. Which is about as safe as not waiting 6-10 seconds between exits...

Your humble servant.....Professor Gravity !

[skr 1]

> thanks for posting that link skr I've printed out the spreadsheet

Just above the link where you got that spread sheet
are two articles about dealing with uppers.

http://indra.net/~bdaniels/ftw/sg_skr_dealing_1_uppers.html

http://indra.net/~bdaniels/ftw/sg_skr_dealing_2_tables.html

Why don't you print those out and ask the people at
your DZ what they think?

The idea was to make a best guess at the tables and
then try them for a season or two and adjust based on
experience.

There is more to dealing with uppers than just the
procedures for exit separation.

I would like to know what other people think about
this approach.

Skr

[AFFI 0]

Good 45 degree information here...