Weights VS Fall Rate

[popsjumper 2]

I've never flown with weights. So...

To increase fall rate, is there some magic formula to increase fall rate to some specific number?

For example:
If one comfortably averages XXXmph, one puts on YYY amount of weight to increase one's comfortable average to ZZZmph?

Or, is it simply a trial/error endeavor?

I am asking for FS considerations...not swooping.

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

[Meux 0]

Last March at the POPS Florida Record Attempt, there was a guy with three jump suits he used to adjust his fall rate.

This doesn't answer your question, it merely suggests that there is another way to adjust fall rate.

Mo

POPS 9876

[popsjumper 2]

Yes...I have 3 jumpsuits...slowest, medium and fastest.
I still ask about weights.

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

[madhatter 0]

IMO it's trial & error. Anyway, it's easier drinking a can of soda / glass of water before your jump to add 0.75 lbs & there's no added external material to mess you up in case of a (accidental) bad landing.

After I learnt to bend my back a bit & relax, I could actually fall away from the bricks & fridges at our dz

I'm 5'7", 180lbs kitted up & had an average speed of 136mph, belly flying, on a 3-way just a few weeks ago.

End of the day, it's all in the mind...

A VERY MERRY UNBIRTHDAY TO YOU!!!
D.S # 125

[popsjumper 2]

So...you know nothing about weights. Thank you.

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

[madhatter 0]

Nope, didnt say that. Just tried weights early on & it stuffed me around more than it was worth.

You said you've never jumped with weights. Why start now? I also have a few jumpsuits to play around with ff speed, but still end up jumping a tight pitts special 99% of the time. Body position is much easier to adapt - you can't get rid of weights when you're playing 'dead spider' during a dive & still going low

A VERY MERRY UNBIRTHDAY TO YOU!!!
D.S # 125

[cocik 0]

I don't know whether there is some general formula (and I doubt, as this depends on several other factors as well), but for me it mostly worked like this ... 1 pound of weight -> add apx 0.7-0.8 mph to general fall rate (I had to do a lot of experimenting with weights in the tunnel, as I am a skinny guy doing RW with big people).

It seems to work similar way when jumping, but I can only judge from 10 jumps when we experimented with different weight belts and altitrack.

Have to agree with working on your body position instead of adding weight. Having too much weight on shifts your CG and your back really hurts after a few hours in tunnel with 2 weightbelts on.

[yjumpinoz 0]

The problem with arching for all your worth in a fairly large formation is that it makes it harder to keep your feet out to relieve tension. I used to use a vest, but I am sold on weight belts. I think of weights like trim in an airplane. They can make it easier to keep in the middle of your range. I am 145# and I have had to wear weight on the outside of 100+ ways and I have had to break out the shirt. It also depends a lot on the formation design. Long story short.....weight belts good.....Looking all floaty on the video bad.

[butlerhr 0]

There does not seem to be a universal formula for speed change vs weight added. As mentioned above, trial and error seems to be the best way. I think the individual shape/flexibility combination is too poorly defined to make a standard calculation feasible. I wear weight with most other FS jumpers to stay comfortably centered in my fall rate range. I have learned that certain shape/weight combinations require X amount of lead. Once I have found that baseline, I have to keep track of my own weight changes and add or subtract 1 for 1 for my body weight changes. Belts are preferable to start as they have minimal effect on the pitch of your body.

[Orange1 0]

Quote

I've never flown with weights. So...

To increase fall rate, is there some magic formula to increase fall rate to some specific number?

For example:
If one comfortably averages XXXmph, one puts on YYY amount of weight to increase one's comfortable average to ZZZmph?

Or, is it simply a trial/error endeavor?

I am asking for FS considerations...not swooping.

I doubt there's a formula. When i started jumping with my team (around 80 jumps), i needed a full weight belt to match their fall rate. Only 60 jumps later and a couple of hours tunnel time, I've shed all my weights and fly perfectly comfortably. So from that experience I guess it will depend on body position as well as the actual "weights" issue. Unless the formula can take degree of arch into account?

Skydiving: wasting fossil fuels just for fun.

[BIGUN 1,051]

You'll need 12 #'s at SF this year.
You may not need all 12.
We're doing some Anvil Brothers dives.
Please come prepared.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[LittleOne 0]

I asked that question at the Perris Big Way Camp. The organizers and more experienced jumpers uniformly answered that there is no formula. The advice, for me, was to start with five lbs. (I had previously never jumped with weights) and adjust accordingly.

[relyon 0]

Just because they don't know the formula doesn't mean there isn't one, because there is.

Ignoring compressibility since fall rate is nowhere near the speed of sound in nearly ever case, terminal velocity is proportional to weight provided everything else remains unchanged. The real problem is determining what that velocity is in the first place, adjusting for it, and keeping everything else the same.

Trial and error is still the fastest for what's being done, but it's not the only way. Those with out-the-door weights of around 100 lbs should increment/decrement in small amounts (say 1 lb at a time), around 200 lbs twice as much, and so on.

Bob

[skybytch 259]

Quote

Or, is it simply a trial/error endeavor?

From what I've experienced, yes.

I have never heard a magic formula for dressing for success - and the decision to wear weights or not is a part of dressing for success. I was told that dressing for success is an art. The "right" amount of weight (or the "right" jumpsuit) for a particular jump is that which allows you to fly with the formation in the middle of your speed range; if the middle of your range is slower than the average speed of the formation then you probably want to add some weight (or a tighter suit). The art is in figuring that out without having already done that skydive with those people, and unfortunately not many people have the knowledge to tell you what you need to wear to put you at the speed you need to be at.

Start with a few (5-6) pounds and see how it goes; then on subsequent jumps adjust as needed or desired. Expect a few non-successes (ie oops that was a few pounds too many as you're dropping below the formation or oops that was a few pounds too few as you're arching your ass off to stay down with the formation) as you learn to figure what you need to wear for a particular skydive.

[kallend 1,623]

Quote

Just because they don't know the formula doesn't mean there isn't one, because there is.

Ignoring compressibility since fall rate is nowhere near the speed of sound in nearly ever case, terminal velocity is proportional to weight provided everything else remains unchanged. The real problem is determining what that velocity is in the first place, adjusting for it, and keeping everything else the same.

But gravitational force is proportional to mass, whereas air resistance (in the relevant range of reynolds numbers) goes as v^2, so your statement is incorrect.


I too have 3 suits - fast, fast and fast, and I still wore weights even on the outside of the TSR 150-way last year. It's not about whether you can arch, it's about being in the middle of your range.

I find that 4 pounds of lead increases my neutral position fall rate by around 2 to 3mph.

...

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

[billvon 2,396]

>Or, is it simply a trial/error endeavor?

Primarily trial and error.

Adding a weight belt over a tight suit increases drag a bit, so if you add a weight belt, start with 4-5 pounds. Then add weight in 2 pound increments until you are near the middle of your range.

Generally I prefer to be a bit underweighted, because I can always arch harder to stay with a formation - and the extra drag comes in handy on fast approaches. However, for someone in the base, or near the base, it can be more beneficial to load up on weight to keep the average fallrate up and save your back.

Warning 1 - if you are significantly underweighted, you won't be able to dock and will show up on video flying in the "W of distress." Even if you can dock, you'll have to keep your legs on your butt to stay down, and this can cause backsliding. So you have to use enough weight to prevent that.

Warning 2 - weight increases your canopy loading AND increases the energy your legs have to absorb on landing, so beware.

[relyon 0]

My post was off the top of my head and I stand corrected about the proportionality. All sorts of higher order adjustments exist for the cases being discussed, but those are even more irrelevant and all but trivially adjusted for. This is skydiving, not pure physics.

I still maintain just because a formula isn't known doesn't mean there isn't one.

Bob

[LemmingBoy 0]

I'm 5'10" ~145lbs and have under 200 jumps, but I routinely jump with people much shorter and heavier than me, so take this for what it's worth.

Based off my Alti-track, I have found that if I wear about 12 lbs of lead my comfortable speed goes up about 7-8 mph. It takes 20 lbs if I want to speed up to about 13 mph above unleaded. I start feeling a forced change in body position after about 8 lbs from the lead dragging down my hips.

To answer to your question, "it depends" for the first few lbs, since it changes your body position. But, if you are going through the trouble of wearing lead, wear enough to know it will have a good effect. I wouldn't even bother with less than 5 lbs on a pickup jump with people I don’t know. If I am wearing that little, I might as well add more to give myself a larger range of fall rates that overlaps with theirs.

[yuri_base 1]

There surely IS a magic formula, and it's very simple:

Amount of weight you need to wear to increase your fallrate by dV is equal to your exit weight W times 2 times dV divided by your fallrate V without weights:

dW = 2*W*dV/V

This is a simple consequence of drag being proportional to the square of speed. I'll leave the derivation to interested readers. This formula is valid for small increments in speed - like a few mph. For large increments, simply square the ratio of the new and old speeds and that's your new total weight.

Example: your exit weight is 150lbs and fallrate is 114mph. You want to match 120mph. You need to wear 2*150*6/110 = 16lbs weight.


Using V = 120mph gives this table which should be good enough estimate in most cases:

Fallrate increase in mph	Weight (as % of your exit weight)

1				1.7

2				3.3

3				5.0

4				6.7

5				8.3

6				10.0

7				11.7

8				13.3

9				15.0

10				16.7

Next request for magic formula!

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[Skydivesg 6]

I wear weights with my 4 way team and most of the time, when I'm in the first 12 to 16 on bigger things.
I usually wear about 8-10 lbs and I would concur with the last post as far as a formula.

I know you didn't want to discuss body position so this is not directed at you but for those who may find value in this information.

Sometimes I find that the weight is not enough (usually right in the middle of a jump) which is when the advice I received from a physical therapist really comes in to play.

When you look at video or stills you will find that most men fly with their knees much farther apart than they think. The exception is usually those who have several hours of coached tunnel.

The more spread apart your knees the harder it is to arch because our hip flexors actually cause us pain and we very quickly relax, going back to a more neutral body position. The pain is felt down the inside front of our thigh. The less flexible one is the more the problem is perpetuated.

Since our best fall rate comes from our hips this presents a problem.

Try it! Stand up and put your knees shoulder width apart and then push forward with your hips as far as is comfortable. At this point most guys say "I don't fly with my knees that far apart" but the video and pics don't lie.

Now bring your knees together with about a 7-8 inch spread and try it again. You can push your pelvis down twice as far with much less effort and easily hold it for 60 seconds. You can also straighten out your lower legs more easily or more importantly, bring the lower legs up out of the relative wind thus helping the fall rate.

As an aside, this also give a better starting point for leg turns for those who want to improve their center point turns.

I have been teaching this technique for a long time and everyone who tries it says it makes a huge difference.

I often coach myself during a skydive using "self speak". When I need more fall rate I don't say "arch more" I say "bring your knees together" this reminds me and I am then able to push down more with my pelvis.

There is also a floor stretch which will help reinforce this position. If anyone wants more info let me know.

Be the canopy pilot you want that other guy to be.

[popsjumper 2]

OK! Thanks guys! I got, I believe, some good info here.

a) a reasonable place to start
b) some guidance on how to adjust as necessary
c) some good input on belts vs vests.
d) a formula to test for accuracy.
e) being a little under-weighted is better than being a little over-weighted (yes, common sense, I know)

All good stuff.

A couple of things.
1) ATTN: Yuri_base:
In your formula, I see where all the numbers are coming from except the "110" you show in your example. From what I gather from your explanation, shouldn't that be "114"?

2) ATTN: ALL
Now. What about landing. I generally understand the dynamics of the effect of additional weight on canopy flight.
What I'm asking is the effects of that lead on your body at touchdown. Running-out or sliding in a landing has GOT to put additional forces on your body. Even a tip-toe stand-up will be different with respect to weight hanging around your back or chest.
Maybe there is some technique to help avoid undue pressure on your back/chest at landing? Maybe there is something in particular to avoid when landing with weights - other than the normal things that apply even without weights.


The main reason I am asking:
(edited to add: My current "comfort zone/range" is between 110 and 135 and I can stay with 'em between 103 and 145)
1) We have a couple of youngster anvils here (avg: 145+) and they quite often jump solos because of their fall-rate and their learning progression is very slow and I'm sure it's frustrating for them.
I've jumped with them before and the results were:
-Jump 1: I got to see a lot of back-pack material and got good video of what an anvil looks like from above.

-Jump 2: Stayed with them but had to concentrate very hard on flying at the outer edge of my range. At about 7K I lost concentration and floated.
-Jump #3 (planned for near future, well, today actually)
Got my fastest jumpsuit out of storage and will try that but I think I will still have to concentrate hard on fall-rate - still on the edge, probably.

Wearing weight should allow me to get the fall rate up and get back into my flying my comfort zone so that I can fly with them more easily and be able to concentrate on teaching and coaching better.

The second reason is for bigways. I'm doing bigger and bigger FS sequential jumps and although I've had only one instance of a problem with fall-rate and having to fly near the edge of my comfort zone, it will be good to get some knowledge and some experience with flying weights in case I need it in the future (and I'm sure I probably will, eh?)

Got Milk?

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

[kallend 1,623]

Quote

e) being a little under-weighted is better than being a little over-weighted (yes, common sense, I know)

The second reason is for bigways. I'm doing bigger and bigger FS sequential jumps and although I've had only one instance of a problem with fall-rate and having to fly near the edge of my comfort zone, it will be good to get some knowledge and some experience with flying weights in case I need it in the future (and I'm sure I probably will, eh?)

Got Milk?

OK, a thought about this.

Big way sequentials have a number of difficulties, one of which is that the base is often weighted up to set a good fall rate. A little fluid dynamics effect called "interference drag" ensures that big ways slow down as they build unless very cleverly engineered, so the people on the outside are often underweighted for reasons that have been described above. If you're docking 149th on a 150 way there's a good chance it will be going pretty slowly by the time you get to dock, so being underweighted is OK. All well and good for a one point big way.

Now break for the sequential and what do you have? A load of slow fallers around the outside and a bunch of anvils in the center which then falls out of the formation. I've been on several 100+ way sequentials now (including 120, 121 and 139 way) and I've seen this happen over and over again. Tony Domenico is the only organizer I've seen who seems to realize this and who engineers his big way sequentials to avoid this problem.

I'm a light guy and always get slotted on the outside (which suits me fine). On big sequentials I prefer to be very slightly overweighted if anything.

...

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

[relyon 0]

Quote

Now. What about landing. I generally understand the dynamics of the effect of additional weight on canopy flight. ...

I've worn as much as 18 lbs to come up to team wingloading (205 out-the-door) and never noticed any difference. Chris Gay wore 90 lbs (not a typo) to do the same thing for the recent CF world record. I guessing he'd be a good person to ask. YMMV

Bob

[kallend 1,623]

Quote

Quote

Now. What about landing. I generally understand the dynamics of the effect of additional weight on canopy flight. ...

I've worn as much as 18 lbs to come up to team wingloading (205 out-the-door) and never noticed any difference. Chris Gay wore 90 lbs (not a typo) to do the same thing for the recent CF world record. I guessing he'd be a good person to ask. YMMV

Bob

Can't say I notice much difference either. Climbing into the plane is another matter!

...

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

[Skydivesg 6]

According to your profile you are loading your canopy right at 1 to 1.
I load mine at 1.6 or 1.7.
If you add 15 lbs (which is a lot) you would be at just over 1.1 which is still very conservative and I doubt that you will notice that much difference in your landings.

However this all depends on how you fly your canopy. Based on your choice of canopy you appear to lean on the conservative side which is not a bad thing.

If you fly your final approach with some brakes applied (even just a couple of inches) you will notice that your decent rate is a little higher and your flare will not be as affective.
If on the other hand you approach in full flight with the toggles all the way up to the keepers, you will notice just a bit more forward speed but that speed will quickly convert to added lift when you flare for landing giving you a more dynamic flare.

If you are of the belief that air speed is your friend during landing then you will actually come to like the added wing loading, even on a lightly loaded Triathilon.

As I said before don't think about it and you will likely not notice much difference.

As far as belt vs vest. I strongly urge you to not even consider a vest, even if someone donates one to you.
A vest cuts into your shoulders and collar area. The more weight the more uncomfortable they are especially during opening and if you are a skinny guy it's even worse. Vests dig into your shoulders even in the plane where a belt is not even noticeable. The belt also puts the weight where your center of gravity is.

As you know about big ways there is always one last "full gear" dirt dive that seems to go on forever. You can be wearing a vest all that time or you can carry your belt over and set it on the ground and then slip it on while walking to the plane.

Go with the belt man.

Be the canopy pilot you want that other guy to be.