Dumbing Down Spotting

[JENNR8R 0]

I've had a heck of a time understanding how to simplify spotting. I've heard that, at best, it is an educated guess that does not require a calculator.

Someone told me recently that there are basically three wind speeds: No wind, light winds and medium winds... any other winds I shouldn't be jumping in.

So what range, in knots, would light winds and medium winds be classified?

What do you call a beautiful, sunny day that comes after two cloudy, rainy
ones? -- Monday.

[mnealtx 0]

At a guess? 0-7kts and 8-14kts.

That takes you up to about 15 mph.

Mike
I love you, Shannon and Jim.
POPS 9708 , SCR 14706

[kelpdiver 2]

the uppers can be a lot faster than 15. That would affect the start of jump run.

[JENNR8R 0]

Yes, I was referring to the uppers... So taking them as a rough average, what would be the range for light and medium?

What do you call a beautiful, sunny day that comes after two cloudy, rainy
ones? -- Monday.

[BIGUN 1,317]

Two different issues here.

If you're dicussing spotting and winds aloft, as you know those can be 50-60MPH which will drastically affect spotting and separation.

If you're talking about surface winds; we don't get skeerted till 30+ mph in Okiehoma.

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

[AggieDave 6]

Average the directions and average the speeds. Use that direction and speed to calculate jump run and exit point.

That method works in many situations, there are times, though, that it will not work using that method and it takes some experience to figure out where you really need to be.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[rehmwa 2]

a - Go to kallend's website and find his spotting/exitorder presos. He doesn't use 'opinion', he goes on reality. You don't find that many places in this sport. It's great info.

b - Understand the reality of the situation. Even if it seems complicated, it's really not.

c - Then, you'll at least have a good 'feel' for how it really 'should' work.


simplified - small planes, small DZ, typical winds (ground and altitude winds in the same direction faster at altitude than on the ground)

1 - fly over the landing area into the wind at altitude
2 - if the plane isn't making very much progress across the ground, wait longer
3 - if the plane is booking along at a good clip (relative to the ground), get out earlier or even before

as you land on and off the airport over time, you'll figure out what "early" and "wait longer" really means

that's it, nothing more complex

...
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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Yes, I was referring to the uppers... So taking them as a rough average, what would be the range for light and medium?

The uppers will affect freefall drift. That's important, but not nearly as important as the winds in the range where you'll be under canopy (below 2500 feet).

have to account for both - uppers to get you open in the right place, the lowers to choose that 'right place'

I don't think there's really a limit for the speed of the uppers. If you are landing in 5 mph winds, it doesn't really matter if it blowing 90 mph at 10000 feet.

...
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

[AggieDave 6]

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The uppers will affect freefall drift. That's important, but not nearly as important as the winds in the range where you'll be under canopy (below 2500 feet).

Yes. Then again, I've watched very noticable drift in freefall when the uppers were over 40kts. I would also argue that the height range for canopies should be 3500ft for your average DZ.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[peek 21]

Quote

I've had a heck of a time understanding how to simplify spotting. I've heard that, at best, it is an educated guess that does not require a calculator.

Generator, you are actually making a post about skydiving?!!!! From the posts I have been seeing in Bonfire lately one would think you are on vacation with nothing to do!

Sometimes the first load of the day is very much an educated guess, (but only if you are in a place where it is OK to land off).

We are a bit casual about that when we are in Illinois. People put a bit more thought into it where necessary.

People usually know where they want to be [open] by the ground winds, but it is not uncommon for people to get blown in freefall to a place they did not expect.

[rehmwa 2]

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I would also argue that the height range for canopies should be 3500ft for your average DZ.

1 - Agree, gotta account for freefall drift, it was a relative comment to the ground cover you can make under canopy even under lesser winds down low.

2 - canopies open at 3500 - I'd argue along with you. Especially with people learning to spot.

Now, take a hop and pop CrW from altitude with several wind layers blowing in different directions..... that's more fun. But nothing a map and a black marker can't help work out.

But sometimes it's just easier to take a cell phone, a couple beers, a sandwich and a bit of confidence along on the jump

...
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

[AggieDave 6]

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But sometimes it's just easier to take a cell phone, a couple beers, a sandwich and a bit of confidence along on the jump

Sounds like my kind of jump.

Quote

Now, take a hop and pop CrW from altitude with several wind layers blowing in different directions..... that's more fun. But nothing a map and a black marker can't help work out.

My wife, who is an engineer, was explaining to me (when she was a student jumper and was trying to figure out spotting) how to use Vector math to have an exact spot that works no matter what the winds are doing. It was over my head, but it worked really well for her. It didn't matter what the winds were doing, it figured the spot out accurately.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[billvon 2,998]

>So what range, in knots, would light winds and medium winds be classified?

Why is that important?

I just do the math in my head. For example - 40kt uppers, 20kt lowers, average of 30kts. That's about 45 feet per second. If you are exiting from 12,500 feet, that's about 60 seconds of freefall. (45*60) = 2700 feet, so you'll drift backwards about 2700 feet, or half a mile, in those winds.

Now add the throw from the plane (usually less than 1/4 mile) and how upwind you want to be from the DZ (in 20kt winds you want to be about 1/2 mile upwind) and you have your spot.

[JENNR8R 0]

I just do the math in my head. For example - 40kt uppers, 20kt lowers, average of 30kts. That's about 45 feet per second. If you are exiting from 12,500 feet, that's about 60 seconds of freefall. (45*60) = 2700 feet, so you'll drift backwards about 2700 feet, or half a mile, in those winds.

Now add the throw from the plane (usually less than 1/4 mile) and how upwind you want to be from the DZ (in 20kt winds you want to be about 1/2 mile upwind) and you have your spot.

[mnealtx 0]

Just average them all together, Jenn... you drift roughly 1/4 mile per 15mph of wind. Average the direction and speeds and you know where your exit point needs to be in relation to your opening point.

Example:

12K; 40mph @270
9k: 30mph @300
6k: 30mph @ 270
3k: 20mph @ 240

That averages out to 30mph @ 270 - so you know that from your planned opening point, you need to be 1/2 mile out @270.

Mike
I love you, Shannon and Jim.
POPS 9708 , SCR 14706

[skydived19006 4]

How about the day’s when the wind at altitude is 90 to 180 off of what it is on the ground. Some will want to run jump run relative to the ground winds, others will want to run jump run into the wind, then move the jump run to the up wind side with 90 degrees off the wind line, or if 180 off top to bottom into the wind, and start exit before you get to the DZ. Last weekend we had the 180 degree thing going on, and on a tandem were still in the “uppers”, we tried to open about straight up, run East to be up wind, then West back to the DZ. Now take into account that the Winds Aloft Forecast is about as accurate as a 3 day WX forecast. In a 182, you can work with the pilot on the climb and work out the wind direction and speed as you climb, more accurate by far, but takes some skill.

Along the same lines, I find it pitiful how poorly people can spot. I jump a 182, and am familiar with the area surrounding my DZ. I can spot form the back of the airplane while hooked up with a tandem, just by watching the roads, and landmarks as we pass over them. Nothing worse than someone who just has to open that door 3 miles out, when it’s blowing 40 knots at altitude, and 10 to 20 degrees!

Then theirs the “Harry Barr Skyvan”, people laying down looking under the airplane and spotting from way out, giving corrections like “fly this way another 5 miles, then have him do a 180 left, and I’ll go from there, relayed back up the airplane through the skydivers. Crazy, but if you’ve jumped that airplane with Harry at the yoke, you know I’m not exaggerating at all (well maybe just a little).

Martin

Experience is what you get when you thought you were going to get something else.

AC DZ

[skr 1]

> I've had a heck of a time understanding how to simplify spotting.

Do you mean to get the main ideas yourself,
or to explain it to a student, or ... ?

Spotting has a *lot* of factors. It's complicated
and takes most people hundreds of jumps to learn.

Even in the mythical old days when theoretically
people knew how to spot it wasn't so. Everybody
knew who could spot and who couldn't :-) :-)

Skr

[popsjumper 2]

mid-70s...Z-hills...most would get the LZ spot...occasionally the asshat would be set up for the shit ponds.

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

[JohnMitchell 16]

People make it more complicated than it is. Get out upwind of the target. On windy days, get out more upwind. Most spots get blown because people don't know how to look straight down accurately and aim the plane, not because they don't know where to get out. Kind of like the gun range. Everyone knows what the bullseye is, they just can't seem to hit it.

Ask the pilot where the spot is when you get on the plane, then guide the plane to it using course corrections.