Accurately gauging altitude by sight alone

[lawrocket 3]

Now that talkback is closed down, I've got a question that has been on my mind for awhile.

It's been said by someone whom I trust completely that altimeters are not to be trusted when gauging height for a swoop. Instead, one should learn to properly gauge height by eyesight.

Question - how can one learn to accurately gauge altitude without confirmation from an altimeter? I.e. if I think I am at 300 feet, how can I confirm that without using an altimeter?

My wife is hotter than your wife.

[Hazarrd 1]

might wanna try the swooping forums...

.-.

[Ron 7]

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It's been said by someone whom I trust completely that altimeters are not to be trusted when gauging height for a swoop. Instead, one should learn to properly gauge height by eyesight.

Question - how can one learn to accurately gauge altitude without confirmation from an altimeter? I.e. if I think I am at 300 feet, how can I confirm that without using an altimeter?

Well. I would not say that I can look down and say "I'm at 325.6 feet". It's more like.."If I hook now, I won't splat".

Example" When you are drinving your car and you pull into a parking space...You turn in and your bumper looks really close to the other car...But somehow you "know" you will fit....You can't say "I am 3 inches away". But you know you will fit.

Its the same thing.

BTW...When I did drink...I liked Corona with LIME...does that save me from being a wanker?

Edit cause I really suck at spelling..Its BUMPER, not Bumber..

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[lawrocket 3]

I didn't try the swooping forum because I thought this is a good general safety and training issue (like at Elsinore where if I happened to look up at the mountaintops in freefall I'd know I am already low).

Ron said:

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BTW...When I did drink...I liked Corona with LIME...does that save me from being a wanker?

You don't drink anymore, so you aren't a wanker. But, no, you WERE a wanker. Limes count, too.

My wife is hotter than your wife.

[billvon 2,434]

>Question - how can one learn to accurately gauge altitude without
> confirmation from an altimeter? I.e. if I think I am at 300 feet, how
> can I confirm that without using an altimeter?

You can't and it doesn't really matter. It doesn't matter if you start a front riser hook at 300 or 400 feet; it matters if you start it at an altitude such that your canopy will recover before impact. That's the sight picture you have to learn. Your eyes will be more accurate anyway; skydiving altimeters simply are not accurate to more than about +/- 200 feet.


Take driving. Do you have a laser rangefinder in your car? If not, how do you determine that you are 1000 feet from a stopped car, and thus need to begin stepping on the brake? Most people don't know or care that they are 1000 or 1200 feet from a stopped car - they just get a feel for the "sight picture" that tells them they have to start braking to avoid hitting the other car. That seems to work pretty well, and an added benefit is that you don't have a laser rangefinder to fail or distract you in traffic.

[ianmdrennan 2]

Check out this thread Altis and swooping

Even Brian Germain is using and advocating instruments for gauging turn initiation height.

Instruments may be inaccurate, but to believe your eyes won't lie to you either is foolishness. It's a combination of both, coupled with an understanding of your wing, with a touch of common sense
Blue skies
Ian

Performance Designs Factory Team

[lawrocket 3]

Thanks, bill. I guess I was kind of overanalyzing it.

My wife is hotter than your wife.

[hookitt 0]

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Well. I would not say that I can look down and say "I'm at 325.6 feet". It's more like.."If I hook now, I won't splat".

Damn it!! I hate agreeing with ron

My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

[sducoach 0]

Accurate or not you must start by using your altimeter. If you start at altitude, set up for an altitude by 500', i.e. 4500, 5000, make your move, be it carving, 270, etc. Let your canopy recover to normal flight and feel the speed and recovery.
Check your altimeter and see what you lost during the move.

Use that as a minimum altitude on your altimeter until you have enough experience to see the approach picture. Yes there will be variables however, your approach picture will change with the conditions and you must learn the differences in the approach picture. More importantly you will see the picture for the no go when you are low.

I asked one of our new "swoopers" a couple weeks ago who was starting way to low and having to go righ into brakes and killing his performance what altitude he was starting at. His answer, 75'. For a 180 toggle turn, that's even pushing a Goliath!

Learn at altitude, using risers, and using the altimeter, get comfortable with the feel then bring it down in little steps.

Blues,

J.E.

James 4:8

[billvon 2,434]

>Use that as a minimum altitude on your altimeter until you have
> enough experience to see the approach picture.

I suppose we will have to agree to disagree on that. I advise newer jumper to never look away from their traffic scan below about 1000 feet. Below that altitude, you need 100% of your attention focused on landing safely, and looking away to your altimeter causes far more harm than good.

[sducoach 0]

Okay Bill let us disagree however, are you teaching new jumpers to swoop their canopies? Are we talking about the same thing here?

Also If you are in a position in the pattern or below 1000' where you cannot take one second to look at your altimeter, the problem is not with the "scan" in the landing pattern, it's with your pattern or your traffic management prior to the pattern.

When I'm flying an approach in an aircraft it is a constant "scan" inside to the instruments and "outside" for traffic and position. No difference with a canopy.

Blues Brother,

J.E.

James 4:8

[billvon 2,434]

>Okay Bill let us disagree however, are you teaching new jumpers to
> swoop their canopies? Are we talking about the same thing here?

I was talking about canopy control training as people downsize, not first jumpers.

>When I'm flying an approach in an aircraft it is a constant "scan"
> inside to the instruments and "outside" for traffic and position.

The only instrument I really look at on final is my airspeed indicator, and parachutes don't have the same issue with stall speeds.

[3ringheathen 0]

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Question - how can one learn to accurately gauge altitude without confirmation from an altimeter? I.e. if I think I am at 300 feet, how can I confirm that without using an altimeter?

I agree with the others that said the sight picture is more important than actual numbers. A typical sport skydiving altimeter doesn't give a particularly precise reading. It's fine for pull time and general flight plan under canopy, but a margin of error of +/- 200 feet isn't acceptable for setting up swoops.

I rarely look at my alti below 1000' or so. Visual cues rapidly become more useful as you descend past this point.

Which brings me to my reason for posting:
The brain uses all sorts of visual cues for depth perception.
Scale, texture gradients, converging lines, and relative movement of different objects in your field of vision and such all are used by the brain to figure out how far away from the planet you are.

Jumping at a new dropzone, jumping over water, or even snow can really screw up your sight picture. Go easy when jumping over different terrain!
-Josh

If you have time to panic, you have time to do something more productive. -Me*
*Ron has accused me of plagiarizing this quote. He attributes it to Douglas Adams.

[SkymonkeyONE 3]

This wasn't a talkback topic anyway, and yes, it's equally relevant here as well as the canopy control forum.

I am reading a lot of stuff here from people who really believe that a site picture is all one needs to accomplish a safe turn; I disagree. If a skydiver jumps at one dropzone his entire carreer and only ever turns one way, then yes, their site picture is going to become attuned to those landmarks and other references. Try taking that approach at an unfamiliar dropzone (or over water) and you will be completely hosed. Your alti, regardless of accuracy inconsistencies, is incredibly important to gaining any type of consistency in your landings. Without it, you may be able to repeatedly pull off "safe" landings, but your accuracy will generally suffer and any attempts to improve your performance landings will be less effective without empirical data to work off of. Yes, I can safely land my canopy without an alti (I did last weekend at Lake Wales), but I prefer to use the same setup on every landing and I use all the tools available to me in order to best accomplish the task.

Chuck

[Bosveld 0]

If we are talking about different DZ's then should altitude ASL not also be taken into consideration?

I don't know the situation in the states, but here in South Africa we have some DZ's at sea level and some are as high as 5000 ft ASL.

Some people have broken themselves on the first load when returning to their DZ after a boogie down at the coast.

a While back we had a lady with 5000+ jumps break herself at our DZ on her first jump there with a very mediocre turn. The experts said it was because she was accustomed to her sea level DZ. She just turned too low for that altitude ASL and never saved herself.

So in this case looking at your Alti or going on feeling would probably not have saved her. When jumping at new altitudes this must be taken into consideration as well when doing your approach.

Whatever the mind can conceive and believe, will be true!

[SkymonkeyONE 3]

Nope, in that instance dumping high on the first load then making several "practice" landing turns on the way down, all the while judging your altitude loss with your alti to form an educated guess as to what your final turn should be would be in order. How's that for a run-on sentence? Throwing a final turn at a new dropzone when you "feel" the setup is right is a great way to find yourself in the "hurt locker."

[JohnMitchell 14]

I know at least some of the top swoopers don't use altimeters. maybe at the level of national competitor it's like training wheels for Evel Kneivel, don't know. I don't use mine for swooping but I'm a pretty conservative swooper, kids and mortgage and all.

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[lawrocket 3]

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This wasn't a talkback topic anyway, and yes, it's equally relevant here as well as the canopy control forum.

The Talkback comment was my homage to your accuracy. Instead of post whoring in there on political nonsense, I should've asked a skydiving question that's been bothering me in here.

My wife is hotter than your wife.

[CanuckInUSA 0]

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Your alti, regardless of accuracy inconsistencies, is incredibly important to gaining any type of consistency in your landings. Without it, you may be able to repeatedly pull off "safe" landings, but your accuracy will generally suffer and any attempts to improve your performance landings will be less effective without empirical data to work off of.

Not long ago I took off my 2nd alti (it used to be attached to my leg straps) when I got my new container and my landings haven't been as consistent as they used to be with my old container. I guess I was trying to nail my swoops without the use of this 2nd alti. But now I'm thinking that I need to put it back on my new rig.

Try not to worry about the things you have no control over

[SkymonkeyONE 3]

Once again, "feel" and totally relying on your site picture might be fine if all you ever do is swoop the beer-line at your home DZ, but if you travel alot, and I do, then you will need some more science on your side if you intend on making it through entrance gates at an unfamiliar DZ. Just my experience.

[ianmdrennan 2]

Yeah I learned that lesson @ Skydive Lebanon last year. I went from blowing through the gates to my home dz to 2 verticals at the unfamiliar dz. It wasn't until then that I realized how many "landmarks" I subconsciously used.

Since I've started using my neptune, my consistency is FAR, FAR better at unfamiliar dz's.

Of course I still exercise caution especially in unfamiliar surroundings, but it does make life a lot easier.

Blue skies
Ian

Performance Designs Factory Team

[Bosveld 0]

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Nope, in that instance dumping high on the first load then making several "practice" landing turns on the way down, all the while judging your altitude loss with your alti to form an educated guess as to what your final turn should be would be in order.

Ok that makes alot of sense to me. In fact it's so logical, can't believe I posted without thinking of that. Thanks!

Whatever the mind can conceive and believe, will be true!