Ways to shorten your glide on final?

[pchapman 261]

kuai43

***
Getting on my rears reduce my vertical speed about 30% and my horizontal is reduced about 15-20%, based on GPS recorded data. The horizontal is a bit harder to nail down due to the fact that the ground speed (GPS) and air speed are not the same.

Better tell the swoopers.
You'll get different results when you don't fly boats loaded at less than 1:1.

Sorry, are you disputing dthames data collection methods for his own canopy?
Or just their applicability to swoop canopies, which aren't the concern of the original poster? Or maybe your use of quotes was messy and you weren't disputing the data itself.


@ stayhigh:
In 2008 a Canadian jumper died from misuse of brakes on approach, with a regular modern canopy at moderate wing loading.
She had only 350 jumps but was a member of a Canadian National Women's team, so must have had some skills and ability to learn. I'm not sure if she went into deep brakes to adjust spacing with a team mate or just to adjust her flight path, but she either stalled it or nearly stalled it, let up too quickly and dove it into the concrete or asphalt. Sure she was a dumbass, but it is a concrete example of getting dead when using deep brakes on approach.

[kuai43 7]

pchapman

******
Getting on my rears reduce my vertical speed about 30% and my horizontal is reduced about 15-20%, based on GPS recorded data. The horizontal is a bit harder to nail down due to the fact that the ground speed (GPS) and air speed are not the same.

Better tell the swoopers.
You'll get different results when you don't fly boats loaded at less than 1:1.

Sorry, are you disputing dthames data collection methods for his own canopy?
Or just their applicability to swoop canopies, which aren't the concern of the original poster? Or maybe your use of quotes was messy and you weren't disputing the data itself.


Point I was making is that he's admittedly sketchy on his horizontal speed data. His evidence of reduced vertical speed is a given as a function of horizontal vs. horizontal (glide slope, right?). After all, isn't that the effect you'd loo for?

Upon looking at his very low wingloading, I doubt the average jumper will experience such an magnified decrease in airspeed.

I've landed on rears quite a bit and couldn't really say I've ever detected any appreciable decrease in airspeed.

Every fight is a food fight if you're a cannibal

Goodness is something to be chosen. When a man cannot choose, he ceases to be a man. - Anthony Burgess

[antieverything 0]

Last time I checked this was "Safety and Training" part of the bigger message board for skydivers. So why wouldn't one want to ask the question I asked here? And more importantly what makes my question eligible for your poor executed "humorous" rhetoric?

If I loose my altimeter,as you suggest, it will do nothing but flap around. What someone needs to learn as some proper English grammar and spelling and lose the attitude. But don't mind me, English is not my first language nor will it be my second. And I am only saying this because your style of answer lies in the border line of cynical and caustic. But if you chose to be that way, at least make no loop wholes in your defense. Don't matter how many jumps you have you can still aspire to some better decency.

[DeeBeeGee 0]

At the risk of remaining on topic..
One trick that is pretty safe to use to adjust your glide is to make yourself small (tuck in arms and legs, arch) to extend your glide or large (spread your arms and legs, dearch) for the opposite effect.
Just make sure you get your feet and knees back together ready for a normal landing before flare height

[dthames 0]

kuai43

*********
Getting on my rears reduce my vertical speed about 30% and my horizontal is reduced about 15-20%, based on GPS recorded data. The horizontal is a bit harder to nail down due to the fact that the ground speed (GPS) and air speed are not the same.

Better tell the swoopers.
You'll get different results when you don't fly boats loaded at less than 1:1.

Sorry, are you disputing dthames data collection methods for his own canopy?
Or just their applicability to swoop canopies, which aren't the concern of the original poster? Or maybe your use of quotes was messy and you weren't disputing the data itself.


Point I was making is that he's admittedly sketchy on his horizontal speed data. His evidence of reduced vertical speed is a given as a function of horizontal vs. horizontal (glide slope, right?). After all, isn't that the effect you'd loo for?

Upon looking at his very low wingloading, I doubt the average jumper will experience such an magnified decrease in airspeed.

I've landed on rears quite a bit and couldn't really say I've ever detected any appreciable decrease in airspeed.

If you are looking at GPS data facing into the wind, your ground speed changes will be different than your air speed changes. If you have your back to the wind, your ground speed changes will be different than your air speed changes, but with a much larger magnitude. So, unless there is specific knowledge of the wind speed and my direction in relation to that wind, I said that getting a handle on the horz values were harder to nail down. The effect on the airspeed will still be the same, but I just could not state numbers with a much confidence as for the vertical aspect.

No, I don't know about faster canopies and I hope the OP is not on one just yet. Note the attached image. The lower line is the vertical speed and the upper line was the horz speed. In this case I was trying to get back to the landing area with a holding crab, largely facing the wind directly and trying to slip to the side as I held. So you would expect the actual horz airspeed change to be more than the recorded ground speed change.

I do think that a person trying to extend their reach on final needs to stay off "rears" at an altitude high enough to allow their main full flight speed so they can have the best flare. That is what I said and what I was taught for normal pattern landing.

[inline vert-horz.jpg]

Instructor quote, “What's weird is that you're older than my dad!”

[mattjw916 2]

Simple answers IMO:

If I want to go further: rears...

If I don't want to go as far: fronts...

NSCR-2376, SCR-15080

[yoink 321]

mattjw916

Simple answers IMO:

If I want to go further: rears...

If I don't want to go as far: fronts...

This is a great example of how a little information can be more dangerous than no information at all.

I'm not necessarily suggesting it in the context of this thread - there's a library of advice up there for the OP to draw on, but I've heard very similar stuff said in the bar after a days jumping with no further explanation...

One of the responsibilities we have as experienced jumpers is to tailor the advice we are giving to the experience of the people receiving it.

[mattjw916 2]

Not really, it is the core of the solution absent the self-aggrandizement, extraneous information, and chest pounding/dick measuring.

Similarly, if someone new asked me how to go forward in freefall, I'd say "legs out" and backwards "feet in, knees together". I wouldn't throw a post-grad textbook on aerodynamics at them.

Tidbits of info such as this don't override previous lessons that should have been learned as a student such as that a canopy should be in full flight to flare effectively, all canopy practice should be completed prior to cutaway decision altitude, practice up high before attempting down low, etc...

NSCR-2376, SCR-15080

[Halfpastniner 0]

Trafficdiver

Going into deep brakes at 100' and letting up at 60' can do loads of damage to you including death.

Also I'm not attacking you I'm describing you. You've admitted you don't jump and it's obvious you don't really give a shit about 1/2 of what you say.

I love this website! You mean he doesn't jump...ANYMORE, right? What he said is absolutely correct given the circumstances he laid out. I fly in different levels of brakes all the time when I fly big parachutes (BASE and tandems). He was even nice enough to include the part about flying in brakes in turbulence.

I think the extra "but if you fuck it up you can get hurt or killed" should be sort of implied with anything you are trying to learn on the internet. These are just idea's that anyone reading should:
1. Take to a coach at their dropzone to discuss further
2. Practice up high (with supervision if available) to understand how the canopy responds.

BASE 1384

[Trafficdiver 8]

Yes. He doesn't jump anymore. You obviously did not read my first post where I said ANYMORE in lowercase.

Yes, I'm sure you use braked approaches, so do I.Did you learn them on the Internet? Probably not. I didn't either.

Can you die fucking up a braked approach? I don't know but I've watched TM's break students when they did them too low.

And I totally agree with you about practicing up high and taking a coach course.

So where are we disagreeing here?

[sheenMatthews 0]

If the airfield is on your RIGHT HAND SIDE, then you are Right Crosswind / Right Downwind or Right Base, and all your turns will be to the Right and you will be flying a Non-Standard Right Hand Circuit Pattern.

Oil Gas Safety Council values the contribution Safety Professionals make to achieve the vision of accident free and safer workplace.
http://ogsc.org/

[Joellercoaster 6]

mattjw916

Simple answers IMO:

If I want to go further: rears...

If I don't want to go as far: fronts...

Complicated answers though: Being on fronts on final, won't necessarily make you end up shorter.

Depending on how long your final leg is, the recovery characteristics of your canopy and how much speed it gains when you lean on your front risers, you might just end up in the same place, with more speed across the ground at the bottom. Or even coming to a stop further away than you would have! Your glide certainly gets steeper when you put the input in, but what happens afterwards is important too.

I'm not trying to be a dick, or calling you a dick (this thread appears to have gotten a little touchy) - and your answer might be right for this individual in this case (sounds like it is for you). But I am saying it's not that simple, even on normal, general-purpose canopies and with normal sorts of pattern.

I like DeeBeeGee's answer, which is true for everyone, though the effect might always not be huge. I have a friend who steers her canopy with booties... it's pretty cool, I keep meaning to try it.

--
"I'll tell you how all skydivers are judged, . They are judged by the laws of physics." - kkeenan

"You jump out, pull the string and either live or die. What's there to be good at?

[mathrick 2]

Joellercoaster

I have a friend who steers her canopy with booties... it's pretty cool, I keep meaning to try it.

Ooh, neat, how does that work?

"Skydivers are highly emotional people. They get all excited about their magical black box full of mysterious life saving forces."

[mcordell 2]

mathrick

***I have a friend who steers her canopy with booties... it's pretty cool, I keep meaning to try it.

Ooh, neat, how does that work?

put your feet in the toggles?

www.facebook.com/FlintHillsRigging

[dorbie 0]

This depends too much on your canopy and headwind to give a single simple answer. For example in no wind rear risers will help flatten your glide slope and lengthen your glide path on most canopies although something like a pulse it's already trimmed flat and it might not help as much if at all. Too much rear riser will have more of a parasitic effect after a point depending very much on the canopy's starting trim. Front risers will typically shorten/steepen your track however that depends a lot on the recovery arc of your canopy, what's the point of getting steep if it's going to give you that energy back coming out of the corner, but held for long enough however it should shorten in under most wings. When you are flying into a strong headwind however depending on the wind speed fronts will speed up your canopy increase penetration and lengthen your glide slope, rear risers will slow you and again depending on wind speed and canopy flight speed, even if it gives you a flatter glide slope relative to the air it will steepen it relative to the ground. Brakes will have a similar effect to rears under both scenarios but are less efficient and the crossover at which the parasitic drag exceeds the benefit will happen earlier making it more prone to shorten your slope after the crossover point of parasitic drag is reached. Now consider that every one of these factors varies with your canopy & wing loading and you have a different continuous response to control input the crossover point of which is affected linearly with windspeed.

Add to this the dynamic effects of any control input as the canopy has more or less energy in the short term until it reaches equilibrium and takes a different amount of time to reach equilibrium. So any change in canopy trim or brake will have a short term dynamic effect that might disguise the longer term effect, e.g. brake input will flatten you out (just like a flare) until equilibrium is reached only after that point will you start to realize the glide slope of your new control input configuration.

It's too complicated and sometimes counterintuitive for simple answers. You literally have to build a model of what is happening in your head including the air speed and ground speed, and test that model against your canopy at your wing loading and see what works. When you change canopy or wing loading you have to relearn what works and doesn't, sometimes it's a matter of degrees but some canopies vary a lot, e.g. a Saber 2 vs a Pulse will definitely give you different answers in some scenarios.

Other safety factors like too much rear riser can easily cause a stall and very deep brakes might too on some canopies and brake configs but WILL make you more vulnerable to a wind shear induced stall in turbulent conditions and letting up risers or brakes will cause the dynamic effect of a surge until equilibrium is reached again and you can see that this is something to be explored cautiously and perhaps at altitude before bringing it into the pattern.

My advice is work on your mental model of what is happening under canopy and try to build your intuitive model around that. That model needs to factor in wind vs. air speed and dynamic short term effects.

As always consult a real canopy control instructor before putting anything into practice, especially before bringing those experiments low.

[dorbie 0]

I should probably have called it induced drag there rather than parasitic drag.

[Joellercoaster 6]

mathrick

***a friend who steers her canopy with booties

Ooh, neat, how does that work?

To start with, she has a Katana 107 and massive competition booties :P

(Sorry for dragging the thread off-topic but... it's interesting? I'm going to ask her for tips and give it a go.)

--
"I'll tell you how all skydivers are judged, . They are judged by the laws of physics." - kkeenan

"You jump out, pull the string and either live or die. What's there to be good at?

[stayhigh 2]

Disconnect RSL, look red, grab red, pull red.

Feet and knees together.

Bernie Sanders for President 2016

[pchapman 261]

Joellercoaster

******a friend who steers her canopy with booties

Ooh, neat, how does that work?
To start with, she has a Katana 107 and massive competition booties :P


Who knows, maybe it does work.
[cynical] Especially if you stretch one leg out as you turn the bootie, pressing that thigh down and leaning on that side of the harness...
[/cynical]

[dthames 0]

stayhigh

Disconnect RSL, look red, grab red, pull red.

Feet and knees together.

No kidding, I was in a tight spot as a junior jumper, flared early, still not okay with a fence in front of me, and about 6 feet off the ground I thought, "I could jump down from here" and let up on the toggles. Plop, belly slide, and shortened my final by just enough not to hit that fence. Effective, but only a little less embarrassing than running it out into the fence.

[dorbie 0]

dthames

***Disconnect RSL, look red, grab red, pull red.

Feet and knees together.

No kidding, I was in a tight spot as a junior jumper, flared early, still not okay with a fence in front of me, and about 6 feet off the ground I thought, "I could jump down from here" and let up on the toggles. Plop, belly slide, and shortened my final by just enough not to hit that fence. Effective, but only a little less embarrassing than running it out into the fence.

I'm pretty sure that was intended as a joke, skydivers have been crippled showing off doing this with no pressure of an imminent collision. The advice on letting up your toggles isn't much better. Learn to carve a flat turn in a flare, practice at altitude, it can be fun.

[SmithK 0]

Try not to fixate on where to turn base and final. That speed will yield the best over-the-ground glide angle.