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Proximity Question

 


chuckakers  (D 10855)

Feb 25, 2014, 5:20 AM
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Proximity Question Can't Post

Hey wingsuiters, got a question for you...

In an article in Skydiving Mag (http://www.skydivemag.com/.../wingsuit-base-myths), author Matt Gerdes said...

"...the closer that we get to the mountain slope, and the more margin that we have. I repeat: the closer you get to the steep mountain face, and the more you stretch that rubber band, the more margin you have. The more you dive, and the faster you go, and the steeper you fly (past your angle of best glide), the MORE margin you have. ...."

I understand that the steeper and faster the glide angle the greater the ability to pull up, but it seems to me that flying close to the terrain has nothing to do with creating a margin and is in fact more dangerous than keeping more distance between the flyer and ground.

I am getting this wrong thinking that flying a line close to the terrain would have a smaller margin than flying the exact same line further from the terrain?


Premier WickedWingsuits  (D 30916)

Feb 25, 2014, 5:45 AM
Post #2 of 23 (2266 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

It is a great theory if you have somewhere to go with all that energy.

Too many people have boxed themselves into corners where all that energy can't be used to outfly the landscape. The danger is when you have it going on you feel like you can outfly anything, but you often can't. It's a trap.

I don't think people are dying because they fly too close and hit the earth. Planning has to exist for the entire flight not just the moment.

So, I personally agree but only in a very specific context. As with most statements if you take them out of context they can sound crazy.


GoneCodFishing

Feb 25, 2014, 5:46 AM
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That's taken out of context. The key words there are "steeper" and "margin", and it's explaining that the steeper the line or approach the more margin there is, as in diving with a GR of 1/1 to clear something by 50ft has more margin than approaching something with a 3/1 GR to clear it by the same 50ft.

In the first case just by relaxing will pull you away from the object if you are not happy with it, in the later you would have to scrape every bit of lift to pull away.

Of course, staying well away from everything is inherently safer, but that section is to explain 'get out of jail' margins when proximity flying, rather than saying kicking grazing cattle as you fly between them is safer than doing a line at skydive altitudes.


GoneCodFishing

Feb 25, 2014, 5:48 AM
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Re: [WickedWingsuits] Proximity Question [In reply to] Can't Post

WickedWingsuits wrote:
So, I personally agree but only in a very specific context. As with most statements if you take them out of context they can sound crazy.

Ha! Ninjaed by WW's Wink


chuckakers  (D 10855)

Feb 25, 2014, 5:59 AM
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Re: [GoneCodFishing] Proximity Question [In reply to] Can't Post

GoneCodFishing wrote:
That's taken out of context. The key words there are "steeper" and "margin", and it's explaining that the steeper the line or approach the more margin there is, as in diving with a GR of 1/1 to clear something by 50ft has more margin than approaching something with a 3/1 GR to clear it by the same 50ft.

In the first case just by relaxing will pull you away from the object if you are not happy with it, in the later you would have to scrape every bit of lift to pull away.

Of course, staying well away from everything is inherently safer, but that section is to explain 'get out of jail' margins when proximity flying, rather than saying kicking grazing cattle as you fly between them is safer than doing a line at skydive altitudes.

I get the science of it. My contention isn't about that. It is with the statement that flying closer to the ground creates a bigger margin than flying higher.

I don't think the author was really trying to say that all other things being equal flying closer to the terrain is inherently safer, but his description could certainly leave the reader with that impression.


GoneCodFishing

Feb 25, 2014, 6:14 AM
Post #6 of 23 (2215 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

I've had to go back and re-read that article, and and i don't think it says the closer-the safer.

It does say that if you are going to get close to the ground, you should do it at the steepest angle possible to have more margin, and towards the end it says "The second ingredient to margin, is of course distance from terrain".


GobbleGobble  (D 32887)

Feb 25, 2014, 10:07 AM
Post #7 of 23 (2026 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

chuckakers wrote:
GoneCodFishing wrote:
That's taken out of context. The key words there are "steeper" and "margin", and it's explaining that the steeper the line or approach the more margin there is, as in diving with a GR of 1/1 to clear something by 50ft has more margin than approaching something with a 3/1 GR to clear it by the same 50ft.

In the first case just by relaxing will pull you away from the object if you are not happy with it, in the later you would have to scrape every bit of lift to pull away.

Of course, staying well away from everything is inherently safer, but that section is to explain 'get out of jail' margins when proximity flying, rather than saying kicking grazing cattle as you fly between them is safer than doing a line at skydive altitudes.

I get the science of it. My contention isn't about that. It is with the statement that flying closer to the ground creates a bigger margin than flying higher.

I don't think the author was really trying to say that all other things being equal flying closer to the terrain is inherently safer, but his description could certainly leave the reader with that impression.

So what are you looking for?


chuckakers  (D 10855)

Feb 25, 2014, 12:06 PM
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Re: [GobbleGobble] Proximity Question [In reply to] Can't Post

GobbleGobble wrote:
chuckakers wrote:
GoneCodFishing wrote:
That's taken out of context. The key words there are "steeper" and "margin", and it's explaining that the steeper the line or approach the more margin there is, as in diving with a GR of 1/1 to clear something by 50ft has more margin than approaching something with a 3/1 GR to clear it by the same 50ft.

In the first case just by relaxing will pull you away from the object if you are not happy with it, in the later you would have to scrape every bit of lift to pull away.

Of course, staying well away from everything is inherently safer, but that section is to explain 'get out of jail' margins when proximity flying, rather than saying kicking grazing cattle as you fly between them is safer than doing a line at skydive altitudes.

I get the science of it. My contention isn't about that. It is with the statement that flying closer to the ground creates a bigger margin than flying higher.

I don't think the author was really trying to say that all other things being equal flying closer to the terrain is inherently safer, but his description could certainly leave the reader with that impression.

So what are you looking for?

Just an answer. As I asked in my first post, "I am getting this wrong thinking that flying a line close to the terrain would have a smaller margin than flying the exact same line further from the terrain?"

Not being a wingsuiter I didn't know if there was something I was missing about proximity vs margins.


jakee  (C License)

Feb 25, 2014, 12:38 PM
Post #9 of 23 (1893 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

In reply to:
Not being a wingsuiter I didn't know if there was something I was missing about proximity vs margins.

The margin he's talking about is the ability to climb relative to your current flight path. So a higher but flatter line gives you less ability to climb, a close, steep and fast line gives huge and almost instant ability to climb.

I think he may have chosen a slightly too visual metaphor to try and describe and, on its own, the paragraph you've quoted is a bit ambiguous. I think if you look at the section as a whole it makes sense.


The111  (D 29246)

Feb 25, 2014, 12:56 PM
Post #10 of 23 (1872 views)
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Re: [jakee] Proximity Question [In reply to] Can't Post

jakee wrote:
a close, steep and fast line gives huge and almost instant ability to climb

Small but important quibble: the "close" part has no effect on your ability to climb. This seems to be the same thing Chuck is commenting on in the OP.


Jbag  (D License)

Feb 25, 2014, 1:27 PM
Post #11 of 23 (1856 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

chuckakers wrote:
GoneCodFishing wrote:
That's taken out of context. The key words there are "steeper" and "margin", and it's explaining that the steeper the line or approach the more margin there is, as in diving with a GR of 1/1 to clear something by 50ft has more margin than approaching something with a 3/1 GR to clear it by the same 50ft.

In the first case just by relaxing will pull you away from the object if you are not happy with it, in the later you would have to scrape every bit of lift to pull away.

Of course, staying well away from everything is inherently safer, but that section is to explain 'get out of jail' margins when proximity flying, rather than saying kicking grazing cattle as you fly between them is safer than doing a line at skydive altitudes.

I get the science of it. My contention isn't about that. It is with the statement that flying closer to the ground creates a bigger margin than flying higher.

I don't think the author was really trying to say that all other things being equal flying closer to the terrain is inherently safer, but his description could certainly leave the reader with that impression.


the article is written for those that want to get closer to the ground. he is saying start with something steep and get flatter and flatter as you get experience. if you want to fly away from a wall then fly 5mi away from the wall....for safety.


jakee  (C License)

Feb 25, 2014, 2:39 PM
Post #12 of 23 (1774 views)
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Re: [The111] Proximity Question [In reply to] Can't Post

The111 wrote:
jakee wrote:
a close, steep and fast line gives huge and almost instant ability to climb

Small but important quibble: the "close" part has no effect on your ability to climb.

Yes, but that's the contrast that Matt is intentionally making, right? The difference between an intuitively safe but actually less adjustable line vs an intuitively dangerous but actually highly adjustable one.


The111  (D 29246)

Feb 25, 2014, 2:51 PM
Post #13 of 23 (1764 views)
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Re: [jakee] Proximity Question [In reply to] Can't Post

jakee wrote:
The111 wrote:
jakee wrote:
a close, steep and fast line gives huge and almost instant ability to climb

Small but important quibble: the "close" part has no effect on your ability to climb.

Yes, but that's the contrast that Matt is intentionally making, right? The difference between an intuitively safe but actually less adjustable line vs an intuitively dangerous but actually highly adjustable one.

Ok, I think I get it now. The big problem I think is his original description makes it sound like he is describing two different attacks of the same terrain. If it's clear that we are describing both two different attacks AND two different pieces of terrain, then I think it is much more clear.


Bluhdow  (B 37052)

Feb 25, 2014, 3:19 PM
Post #14 of 23 (1734 views)
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Re: [The111] Proximity Question [In reply to] Can't Post

Which is more dangerous? All of your questions answered in one easy guide (where a greater symbol indicates a greater level of danger):

1. Close > Far
2. Flat > Steep

Therefore:

3. Close + Flat = DANGER!
4. Close + Steep = "More Safe"
5. Far + Steep = "Most Safe"
6. Far + Flat = ? ;depending on how far, how flat, weather conditions, time of day, experience level, suit type, and whether you prefer dogs or cats.


chuckakers  (D 10855)

Feb 25, 2014, 5:47 PM
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Re: [jakee] Proximity Question [In reply to] Can't Post

jakee wrote:
In reply to:
Not being a wingsuiter I didn't know if there was something I was missing about proximity vs margins.

The margin he's talking about is the ability to climb relative to your current flight path. So a higher but flatter line gives you less ability to climb, a close, steep and fast line gives huge and almost instant ability to climb.

You make it sound like a higher path is somehow going to be inherently flatter than a lower one and that's not true. If the flyer can have a particular glide angle at treetop level that same glide angle can be flown 20, 50, or 100 feet higher.

Two identical glide angles flown at different altitudes will result in identical capabilities to climb.

Once again, speed may equal safety, but speed with distance gives bigger margins than speed without it.


Bluhdow  (B 37052)

Feb 25, 2014, 7:04 PM
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

chuckakers wrote:
You make it sound like a higher path is somehow going to be inherently flatter than a lower one and that's not true. If the flyer can have a particular glide angle at treetop level that same glide angle can be flown 20, 50, or 100 feet higher.

From the same exit point, in the same direction, the higher path will inherently be flatter, at least for a period of time.

Look at the attached very-scientific paint file. The steep path (1) is in contrast to the flatter path (2). The only way to get the same glide angle at a higher altitude is to fly flatter for a period of time before going steep again (3).

My point is that sometimes what you are saying is right. That is, that you can be higher and still fly steeper from some exits. But not always.


(This post was edited by Bluhdow on Feb 25, 2014, 7:06 PM)
Attachments: WS_Paint.jpg (16.2 KB)


Bluhdow  (B 37052)

Feb 25, 2014, 7:11 PM
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Re: [Bluhdow] Proximity Question [In reply to] Can't Post

More scientific data:

What you are saying will be true in this scenario, where the exit is from a heli and there is plenty of altitude. The limiting factor is the fixed exit point, which definitely has the ability to force you into flatter flying, if separation is what you're after.


(This post was edited by Bluhdow on Feb 25, 2014, 7:12 PM)
Attachments: WS_Paint 2.jpg (18.1 KB)


chuckakers  (D 10855)

Feb 25, 2014, 7:52 PM
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Re: [Bluhdow] Proximity Question [In reply to] Can't Post

Bluhdow wrote:
chuckakers wrote:
You make it sound like a higher path is somehow going to be inherently flatter than a lower one and that's not true. If the flyer can have a particular glide angle at treetop level that same glide angle can be flown 20, 50, or 100 feet higher.

From the same exit point, in the same direction, the higher path will inherently be flatter, at least for a period of time.

Look at the attached very-scientific paint file. The steep path (1) is in contrast to the flatter path (2). The only way to get the same glide angle at a higher altitude is to fly flatter for a period of time before going steep again (3).

My point is that sometimes what you are saying is right. That is, that you can be higher and still fly steeper from some exits. But not always.

Exits only affect the big picture for a short period of time. After that your attached very scientific graphic and it's varied glide paths are for the most part a matter of choice. Once sufficient airspeed is achieved the flyer can vary altitude along a glide path gradually with minor inputs and minimal sacrifice of lift-generating speed.

Are there jumps that are safest flown with a high-speed, steep angle entry into to the run? I'm sure there are, but that's not the conversation here. We are talking about the big picture, not the exit and initial freefall.

In your attached graphic, routes number 2 and 3 could have been flown exactly like number 1 but at a higher altitude with the exception of the earliest part of the freefall when speed must be achieved to produce lift.

Beyond that the altitude of the line has no bearing on the the angle.


GobbleGobble  (D 32887)

Feb 25, 2014, 8:04 PM
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

chuckakers wrote:
Bluhdow wrote:
chuckakers wrote:
You make it sound like a higher path is somehow going to be inherently flatter than a lower one and that's not true. If the flyer can have a particular glide angle at treetop level that same glide angle can be flown 20, 50, or 100 feet higher.

From the same exit point, in the same direction, the higher path will inherently be flatter, at least for a period of time.

Look at the attached very-scientific paint file. The steep path (1) is in contrast to the flatter path (2). The only way to get the same glide angle at a higher altitude is to fly flatter for a period of time before going steep again (3).

My point is that sometimes what you are saying is right. That is, that you can be higher and still fly steeper from some exits. But not always.

Exits only affect the big picture for a short period of time. After that your attached very scientific graphic and it's varied glide paths are for the most part a matter of choice. Once sufficient airspeed is achieved the flyer can vary altitude along a glide path gradually with minor inputs and minimal sacrifice of lift-generating speed.

Are there jumps that are safest flown with a high-speed, steep angle entry into to the run? I'm sure there are, but that's not the conversation here. We are talking about the big picture, not the exit and initial freefall.

In your attached graphic, routes number 2 and 3 could have been flown exactly like number 1 but at a higher altitude with the exception of the earliest part of the freefall when speed must be achieved to produce lift.

Beyond that the altitude of the line has no bearing on the the angle.

If you are focusing the conversation around flying close, and Matt was. Then the steeper you are flying, the more energy you have. Your ability to translate that energy into lift and climb away from the object is increased over a flatter flight path.

The conversation isn't about proximity flying being safe. The conversation was about misconceptions about proximity flying. Flight is about energy management. The more you have, the more you can do.

If you want to argue that flying next to shit is dangerous, great. I don't know that anyone is going to argue that point.

So again, what is it you're looking for?

The "big" picture in the article was proximity flying.


Mikki_ZH  (Student)

Feb 26, 2014, 3:37 AM
Post #20 of 23 (1456 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

Where the hell is Jarno???
Smile


Bluhdow  (B 37052)

Feb 26, 2014, 12:34 PM
Post #21 of 23 (1298 views)
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Re: [chuckakers] Proximity Question [In reply to] Can't Post

Matt is clarifying some of the points he made here:

http://www.basejumper.com/...0;page=unread#unread


hjumper33  (F 1)

Feb 26, 2014, 8:46 PM
Post #22 of 23 (1130 views)
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Re: [Bluhdow] Proximity Question [In reply to] Can't Post

So what I take away from Matt is that im invincible as long I fy as close to the ground as possible. I hate that douche anyway.


Bluhdow  (B 37052)

Feb 27, 2014, 9:41 AM
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Re: [hjumper33] Proximity Question [In reply to] Can't Post

Well that escalated quickly.



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