The 45 Degree Rule… IS DEAD.

[popsjumper 2]

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See, I don't think it's gravy. the math is the gravy.

OK. We differ. Evidently it's philosophical differences or POV difference and that's fine.

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The meat is that you need to develop the ability to confirm, real time (before climbout), based on direct observation, that the calc remains true.

That generates another question for me.
How does one develop that ability? Without the calculations to start with, it must be trial and error...not so good IMO. My answer would be to learn the math, practice what you've learned with a mentor to guide you, talk to experienced jumpers who can do those things and drill, drill, drill.

And yes, I totally agree that actually looking and evaluating and adjusting are all necessary and good things....we'd be hosed a lot more often if we didn't do that. Good point as you've said all along.

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(spotting skills come in handy here - use a hard edge on the plane - window frame, edge of door etc to reference the progress across the ground)

Yes, I can agree with that except for one thing...it re-enforces the idea that you can use the aircraft to determine the location of the plane over the ground (there's a name for that location but it escapes me at the moment) For ground track and distance traveled it works well but not so much for location...it could lead to just enough error to put you off site.

Yes, for the youngsters, in the big scheme of things, because we fly parachutes that have forward drive and can penetrate against the wind we have a rather large margin of error for that location that we didn't have under rounds.

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blues - this is always a worthwhile discussion. And Brian's attitude here is a great role model for us. We always learn.

Totally agreed across the board. I was happily impressed with Brian's response here. I wish more could set aside the egos and discuss rather than argue and turn deaf ears.


For you young jumpers out there reading this thread, please take note:
1. Brian's attitude. We'd all be better off having one such as that. Take a moment to thank Brian personally.

2. Kallend's presentation. It's a very important demonstration of one way to keep yourself safer in the sport. Take a moment to thank John personally.

3. Rehmwa's suggestions. It's always important that we look, evaluate and adjust. Learning how to do that is very important. And that applies to all areas of skydiving exit to landing. Take a moment to thank Rehmwa personally.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[kallend 1,675]

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..Well, a previous poster cast doubt on jumpers' abilities to do any calculations. Now you expect them to make adjustments from your "simple" table. make up your mind what it is that you are trying to say.

Okay, now you are just being silly.

Nope. Just emphasizing that there is NO SUBSTITUTE for understanding what is going on. Tables, GPS data, etc. are all very fine, but only actually understanding the dynamics of the process is what will allow you to deal with the unexpected situation.

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

[popsjumper 2]

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A very high percentage of all jumpers on a typical load could not tell you what the upper wind velocity was, let alone the direction.

Why is that? Because they haven't learned to spot.

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I'd be willing to bet a lot that, in the last year, of the millions of jumps made in the world, only a tiny tiny fraction of those jumpers actually did the math in their head to derive a time for whatever exit separation distance they wanted.

I'd take you up on that. Doing the math enough generates the experience where you learn that certain directions and speeds result in similar numbers. You wouldn't know that unless your started out with the basics and built a foundation.

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But I will also bet that almost all of those jumpers, if told that XX seconds is the normal group separation for the conditions at the moment will be smart enough to add more time to account for a big way in front of them.

Not the youngsters. It's why we have to teach them. And we have to teach them how much time.

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And most big ways I've been behind, at least one of the participants was reminding the groups behind them to give them more time.

And you may have noticed that those guys on the bigways are experienced people. They know that communication is important. They know that a little extra time for groups size and discipline is required. Youngsters have to be taught those things.

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This is not a problem: I've seen that typical jumpers do get this, and they do attempt to adjust accordingly.

Because they have been taught and/or told.

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Any method is useless if it is impractical and/or complicated and/or goes against the known abilities and actual behavior of the bulk of the skydivers on the load.

Known abilities. That, my friend is why we are discussing these things. More to the point, the known inabilities of those who rail against and reject and ignore common sense, instruction and the things that history has taught us.

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There is absolutely nothing wrong with teaching everyone the logic and the method

Now you have me confused. Earlier you were railing against the method.

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...lbut the reality is that it isn't being put into practice.

Which is the whole point of teaching...so it can be put into practice.

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The original thread (that you started) is 7 years old, and don't you think it's telling that the author of the best selling canopy book and teacher of the most famous canopy course is (was) advocating the 45 second rule?

Yes. It is very telling. It tells how misconceptions can be perpetuated and it's more common than you think. It's an uphill battle dealing with those misconceptions. Except in the cases like Brian's where he is man enough to own up to a mistake.

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(I heard "the 45 second rule" being urged on a load last month.)

Yes, I heard the same guy (probably) saying it in his FJC. And yes, it's been discussed with him several times in the past....only to be ignored.

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It seems to me that you have to keep beating down the "45 second rule" like a whack-a-mole because no one is advocating a practical workable substitute.

Yep. And sometimes it gets frustrating but if you look at the big picture, there are thousands of us out here and not everyone posts here. We pick 'em off as we can both here and at face-to-face opportunities.

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requires the jumper to know only one variable that is apparent only from the grouping on the plane: exit separation in distance.

OK. One last time, Peter and then I'm done. Two words: Device Dependency...what to do if you don't have that device to depend on? You're lost without the education of the concepts, and the arithmetic, behind it....as well as the prior experience.

Well, you could limit yourself to only those planes, well-trusted pilots and DZ who use it. And you are free to stay in that arena if you wish.

I'll repeat what John said, "

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Knowledge is power. GPS is a crutch. A very clever crutch, but a crutch nonetheless.

"
Either you get it or you don't.

G'day.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[billvon 2,467]

>Why is that? Because they haven't learned to spot.

?? You can spot and not know the wind velocity. The forecast is often wrong, which is why spotting is still important.

I think doing the math is great and is a good exercise. But as Div suggests almost no one does it. Indeed the only time I ever care about it is for the first load of the day. After that, "we were too close last time" = "leave more time" and "we had plenty of space last time" = "that exit separation is OK." And overall, THAT is a more important meme to propagate, I think, than distance=(groundspeed of aircraft + (winds at opening*cos(angle of lowers to uppers))*time.

[3mpire 0]

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***I see, 5 loads of jumpers put at risk so you can evaluate someone's spotting ability. Got it.

It's an A license requirement that you essentially do all of that anyway. You are supposed to brief the pilot, you are supposed to give corrections and you are supposed to spot.

Nobody says that the rest of the load has to get out. Each jumper is responsible for their own spot. And everyone should know how to spot, right?

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"Make someone spot for the whole load, and require that everyone open up wind and in a position where people are able to promote a smooth pattern for landing. "

You are being inconsistent.

I'm entirely consistent. You are conflating the procedure for exiting an aircraft with evaluation criteria for spotting. Requiring the load to open up wind is a criteria for evaluating the quality of the spot. If the entire load doesn't open up wind, if people land off, or if they require a go around, then obviously it was a bad spot and the person needs to work on it.

Nothing about that evaluation criteria suspends the normal procedures for the rest of the load. It is still each jumpers responsibility to check their spot before they get out.

You do kind of get into semantics with your 20 way analogy. So just to clarify, the rule about each jumper being responsible for their spot should not be interpreted literally. what it really comes down to is each stick is responsible for their spot.

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Everyone spotting for themselves is not very convenient on, say, a 20 way.

that 20 way certainly has someone designated as the spotter for the stick. everyone on that jump should be comfortable with that person's spotting ability as they are essentially trusting that they will make sure the whole group has a safe spot. but really that is still in the spirit of what I wrote, because they are taking responsibility, if indirectly, by designating someone in advance as the spotter.

in context, you will see that this is all entirely consistent. and it isn't really that complicated. know how to spot, make sure you stick communicates with all the other sticks, communicate with the pilot, make sure your stick checks the spot before exiting. land. pack. repeat.

unless i'm dense and missing your point, and you're arguing that it isn't possible to evaluate spots and it isn't possible to expect each stick to know where they are getting out relative to the ideal spot, i'm not quite sure what you are arguing for.

[rehmwa 2]

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And most big ways I've been behind, at least one of the participants was reminding the groups behind them to give them more time.

And you may have noticed that those guys on the bigways are experienced people. They know that.........

and sometimes they are just bossy assholes

...
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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agree with that except for one thing...it re-enforces the idea that you can use the aircraft to determine the location of the plane over the ground (there's a name for that location but it escapes me at the moment) For ground track and distance traveled it works well but not so much for location...it could lead to just enough error to put you off site.

I think we're talking past each other here. I'm just talking about spotting. Look straight down past a structural reference. I suspect that's exactly how you do it. point is, the way to eyeball the spot location is the same method to also get a feel for ground speed visually.

If not, how do you spot?

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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

[3mpire 0]

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How would you evaluate it?

In Reply To
Make someone spot for the whole load, and require that everyone open up wind and in a position where people are able to promote a smooth pattern for landing.
I would like to think that everyone could/would do as you indicated. I do similar. Personally, I totally agree with making them actually do it, just as you do, to determine success but with one exception.

I let them do the math to determine earliest exit point, middle (perfect) exit point and latest exit point. Then take them up on the plane. I tell the pilot to fly off-line to check to see if the student does proper corrections. Then they tell me when they get to the first exit point and I verify or deny. I tell them on the ground, "If I land off, you will have to repeat the class and try again."


I, like you, prefer to do this on a 182 or such so that there would be fewer jumpers involved in the process and I would always take back control if the student was getting it so wrong as to endanger anyone with off landings. If their spotting is "good enough" to minimize the danger to other jumpers, I'll go ahead and exit.

On a larger plane involving more jumpers, I will let them do the same but I'll take control just before exit and take the responsibility myself instead of putting on the student.

Once he can prove some consistency, he on his own.

Good stuff, 3mpire.

Excellent points. There isn't much point in having an evaluation without the evaluator, and the evaluator can also serve as a safety check to keep a dangerous situation from developing. Your method is very similar to the one I experienced as a student and it seems to work great for me.

Having the pressure of spotting for other jumps as part of the evaluation is a great motivator to get it right. Because if you do it wrong not only do you not "pass" but you also inconvenience everyone else, so you have extra motivation to get it right.

Which is why I'm a little confused why this is a problem. How to spot and how to evaluate that spot has been part of the sport from the beginning, so it's not like there aren't methods for solving this problem already available.

To me it doesn't seem to be a question of "how do we solve this problem" it's a question of "why aren't we just making people do it over and over until they learn it".

[feuergnom 22]

kallends tables and equations have been around for the last ten years - how come it took YOU so long to adopt the truth??????

The universal aptitude for ineptitude makes any human accomplishment an incredible miracle

dudeist skydiver # 666

[mjosparky 3]

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Many planes have them. Why not have the pilot announce the value as he begins jump run, and then a quick consult with a simple table will give you the right number? It's the simpliest fucking thing ever!

No, the simplest thing is to learn how to do things without the aid an electronic device. If the mental calculations are too complicated for you or if you just don’t feel the necessity to learn them maybe you should take up something simpler, maybe needle point or stamp collecting.

Sparky

My idea of a fair fight is clubbing baby seals

[popsjumper 2]

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And most big ways I've been behind, at least one of the participants was reminding the groups behind them to give them more time.

And you may have noticed that those guys on the bigways are experienced people. They know that.........

and sometimes they are just bossy assholes

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[kallend 1,675]

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You do kind of get into semantics with your 20 way analogy. So just to clarify, the rule about each jumper being responsible for their spot should not be interpreted literally. what it really comes down to is each stick is responsible for their spot.

OK, so you didn't actually MEAN what you WROTE.

Let us know in future that what you write is not what you mean, and you won't get called on it.

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unless i'm dense and missing your point

Yep.

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

[popsjumper 2]

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I think we're talking past each other here. I'm just talking about spotting. Look straight down past a structural reference. I suspect that's exactly how you do it. point is, the way to eyeball the spot location is the same method to also get a feel for ground speed visually

Well, maybe we hve different definitions for jsut what spotting is. My definition is all-inclusive...not just looking past a structural reference.

I use no structural references. For a reason: You cannot be sure that the structural reference you are using is really perpendicular to anything other than other structural references.

You might notice that the point you are looking at on the ground will change depending on the attitude of the plane leading you to a false determination. In general, that's OK because the froward drive of the canopies we mostly fly today will mask and cover up that error....to a point.

I use the horizon. Perpendicular lines from two points on the horizon 90 degrees apart to find the intersection of the two lines. The horizon doesn't change...well, it hasn't so far.


From the SIM:

Cat D, F 2
2. Overview of aircraft spotting and jump-run procedures
(what “spotting” means):
Note: It is recommended that a jump pilot explain spotting procedures
in Category E.
a. determining the best opening point
(1) calculations from wind forecasts
(2) observation and discussion of previous jumpers’
canopy descents

Cat D, F 2
3. During jump run, observe spotting procedures and
demonstrate the technique for looking straight down
from the aircraft.
a. Sight from the horizon looking forward.
b. Sight from the horizon looking abreast.
c. The junction of the two perpendicular lines
from the horizon marks the point straight below
the aircraft.


The rest of it is covered fairly well in Car E


Did that answer your question?

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[3mpire 0]

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OK, so you didn't actually MEAN what you WROTE.

now you're just being obtuse. i meant what i wrote and in both posts I said a jumper is responsible for their spot, even if by being responsible that means they designate a member of their stick to spot.

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unless i'm dense and missing your point

Yep.

which is? lol (i'm not holding my breath for an answer)

i'm done with this thread. but you can have the last word if you want, that's cool. just another day in dropzone.com paradise

[popsjumper 2]

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You can spot and not know the wind velocity. The forecast is often wrong, which is why spotting is still important.

You missed something somewhere along the line, Bill.
You cannot spot properly without some clue as to wind direction and speed. Well, you could but let us know how your off landings went, eh?

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But as Div suggests almost no one does it.

I'm going to question that.
-How do you know that the load spotter didn't do the simple arithmetic in his head?
-How do you know that the spotter hasn't done the math so many times that he can look at the winds aloft chart and plot an exact spot without a pencil in his hand?

Well one way is off landings. Maybe we should be considering of landings, how often they happen and the causes. I'm willing to bet that spotting skill, or more to the point, the lack of spotting skill is a major cause.

On the other hand, yes, with enough trial and error you can eventually stumble on getting it right.

This is what you want to avoid. The trial and error. It's why we teach spotting. A good instructor will teach the entire thing, not just stick your head out the door and look for clouds, traffic and the LZ.

We're having this entire conversation because that stuff is NOT taught properly in many, many, many cases.

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Indeed the only time I ever care about it is for the first load of the day. After that, "we were too close last time" = "leave more time" and "we had plenty of space last time" = "that exit separation is OK." And overall, THAT is a more important meme to propagate, I think, than distance=(groundspeed of aircraft + (winds at opening*cos(angle of lowers to uppers))*time.

You are regurgitating what has already been said through out the thread.
-Do it up front
-Adjust as needed

The rest is about techniques to accomplish the same goal.


Why are we debating something so basic to skydiving.
You either know how to spot properly or you don't. If you don't get someone to teach you and/or read the SIM and other treatises on the subject.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[popsjumper 2]

OK. I've said enough. I am being repetitious and it's getting to the point of gum-flapping at the wind.

Back to the 45-degree rule...at least most of us here agree that it doesn't work well.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[kallend 1,675]

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OK. I've said enough. I am being repetitious and it's getting to the point of gum-flapping at the wind.

Back to the 45-degree rule...at least most of us here agree that it doesn't work well.

Fixed it.

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

[billvon 2,467]

>You cannot spot properly without some clue as to wind direction and speed.

Correct. You need some vague clue (like ground winds.) But after that first spot - which may indeed have people landing off - you correct from there. Remember where your first spot was? People opened half a mile south? You just move the spot half a mile north. You don't need to know what the winds are, although it is easy to estimate them once you have a spot dialed in.

There's a reason that that first load is often called the "wind dummy" load. Often it's because the person simply didn't check, but just as often it's because the forecast is wrong.

>How do you know that the load spotter didn't do the simple arithmetic in his head?

Cause I know many of the people who spot for us and they can't balance their checkbooks, much less figure out the cosine of 15 degrees. (Or the conversion of KIAS to feet per second.)

>How do you know that the spotter hasn't done the math so many times that he can
>look at the winds aloft chart and plot an exact spot without a pencil in his hand?

That's closer to what happens, I think. But I'd ask it this way:

How do you know that the spotter hasn't spotted that airplane in those conditions so many times that he just knows where the spot is on a normal morning, WITHOUT knowing the winds?

Now, you could argue 'well he really does know the wind because the winds are almost always about 10kts out of the north, unless a storm is coming in which case they're out of the south, and if it's really dry that means a Santa Ana which means 30-40 out of the East.' But there are really are people who have been spotting so long that they just know that they have to move the spot east on a dry, gusty day.

None of that, of course, is meant to imply "people shouldn't do the math." I'm all for that. But it is quite possible to spot without it.

>You either know how to spot properly or you don't.

That's like saying you either know how to do RW or you don't. There are many gradations between those two extremes. There are people who are excellent spotters who can't add, and there are people who have PhD's in math that I wouldn't let spot.

[kallend 1,675]

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There are people who are excellent spotters who can't add, and there are people who have PhD's in math that I wouldn't let spot.

My late wife had a PhD in math and I certainly wouldn't have let her spot. She could get lost driving home from the grocery store.

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

[demoknite 0]

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...Yup, I got reamed on dropzone.com....

Who hasn't?