lost at 14,000 ft - furry hat scientist advice needed

[hairymango 0]

So you exit the plane the plane at 15,000ft (tandem under drouge) and your nice new fur hat with a protrack in it (not much weight) decides it doesnt like you anymore and detaches itself from your head at about 14,000 ft , your under canopy at 4,500ft.

Now the question is does the hat drift further down the wind line than the point you opened or does it not drift as much as you did in freefall!? 30 knot winds at 15,000ft, no wind on teh ground

So do I search more around where I exited the plane OR search further down the wind line from were I opened OR search around were i opened???

Im getting mixed opinions so Im putting it out there and maybe someone has some scientific knowledge of furry hats in freefall

Thanks
Adam

[drdive 0]

Just hope for a friendly farmer!! I lost my helmet and skytronics on a jump after apparently failing to connect my strap. A week later, a farmer near our rural drop zone, came by with my helmet stating he found it IN HIS BACK YARD !!! The helmet was no worse for wear, but the skytronics was toast.

"We saved your gear. Now you can sell it when you get out of the hospital and upsize!!" "K-Dub"

"

[darkwing 4]

The hat drifts much further in freefall, because it falls slower than you, which means it is in the 30 knot winds for longer.

-- Jeff
My Skydiving History

[BIGUN 1,053]

Using a map....
Place a dot where your exit point was.
You lost it at 14,000'
Now, draw a line from the exit point along the wind line for the day for 28,000' (about 5.3 miles).
From that same dot, draw two parrellel lines on either side of the first line about 15 degrees from the now center line for the same distance, giving you an expanding range from 30 degrees to about 45 degrees at the furthest distance.
Then calculate the number of square acres within that vector fan for helmet exploration.
Now, take out your wallet and go buy another helmet.

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

[breadhead 0]

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Now the question is does the hat drift further down the wind line than the point you opened

Yes.

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search further down the wind line from were I opened

Correct.

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Im getting mixed opinions

I will be further down the wind line than where you deployed. No discussion there. The only point of discussion is: how much further?

All the input-parameters are very inaccurate:
- The fallrate of the hat: 10fps? 20fps? 30fps?
- The windspeed: 30kts at 15000ft, but what about winds at 7000ft?
- The winddirection: different directions at different altitudes

You are looking at a search area of several square miles. Short answer: forget about it.

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protrack

The good news is: L&B are the best. Send them an email, tell them your story. You will be surprised by their reaction.

Mike

[Mr17Hz 1]

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So you exit the plane the plane at 15,000ft (tandem under drouge) and your nice new fur hat with a protrack in it (not much weight) decides it doesnt like you anymore and detaches itself from your head at about 14,000 ft , your under canopy at 4,500ft.

Now the question is does the hat drift further down the wind line than the point you opened or does it not drift as much as you did in freefall!? 30 knot winds at 15,000ft, no wind on teh ground

So do I search more around where I exited the plane OR search further down the wind line from were I opened OR search around were i opened???

Im getting mixed opinions so Im putting it out there and maybe someone has some scientific knowledge of furry hats in freefall

Thanks
Adam

I'm not a physisist - but based on what I retained from highschool physics and coffee table physics books - this would depend on the difference between uppers and lowers...

You being big and heavy with a tandem student - are going to take longer start accellerating horizontally (With the wind) - but after you're coasting at your terminal horizontal speed - it would also take you longer to slow down...

Your hat is likely to catch the wind faster (it has more wind resistance so is more likely to move with the wind) and because it is light it will not have as much resistance to speeding up or slowing down quickly...

so, if the winds were calm or low all the way down, your hat probably went farther than you did - because it traveled faster through the wind.

but if the uppers were high (30?) and aruond 10k they dropped to 5mph - your hat would have slowed down to 5mph almost immeadiatly while you were still cruising at 30mph slowly going down to 5mph. This would give you the ability to pass up your hat because you kept the horizontal speed for longer..

I would think that the difference in wind speeds would have had to be pretty severe for you to have gone futher than your hat. on an average day I suspect that your hat would have traveled 2-3 times further than you did (partially because from 4,500 to 0 you controlled your direction, where the hat kept going its merry way).

again - i'm no expert; but its fun to think about these things :)

Matt Christenson

[email protected]
http://www.RealDropzone.com - A new breed of dropzone manifest software.

[kingbunky 3]

Quote

Using a map....
Place a dot where your exit point was.
You lost it at 14,000'
Now, draw a line from the exit point along the wind line for the day for 28,000' (about 5.3 miles).
From that same dot, draw two parrellel on either side of the first line about 15 degrees from the now center line for the same distance.
Now, take out your wallet and go buy another helmet.

i think you have what may be the best practical response! if the op has lots of time, the first method would work, eventally. like stephen wright says, "everything is within walking distance if you have enough time."

"Hang on a sec, the young'uns are throwin' beer cans at a golf cart."
MB4252 TDS699
killing threads since 2001

[breadhead 0]

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this would depend on the difference between uppers and lowers...

Hardly. It depends on the uppers and the lowers themselves, not as much on the difference between them. The transitional effect you describe certainly exists, but it lasts only "seconds". The hat falls "minutes" from 14kft. The overall effect of the transition between wind layers will be much smaller than the inherent margin of error.

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This would give you the ability to pass up your hat because you kept the horizontal speed for longer.

No way. For all practical purposes: if it falls slower, it will drift further.

(For the experts wanting to split hairs: I can imagine an artificial experiment that would reverse this logic. However, such an experiment would have no practical relationship to the hat&skydiver-scenario. It would require the slow-falling object have (1) virtually zero drag in the horizontal direction while having (2) a large enough mass/inertia).

[JohnRich 4]

Search for the thread titled "freefalling helmets". There are some posts in there from folks who recovered helmets after they came off in freefall, and recorded their terminal velocity on their instruments. That will give you an approximate fall rate.

Then calculate the time in the air subject to wind drift based upon the altitude from which it fell. Then, use that with the wind speed, to get distance it may have drifted. Look at the aerial photo and pinpoint a search area.

You've got to at least try to find the helmet. Otherwise, you'll always wonder if you would have stumbled onto it right away. Yeah, the odds of finding it, depending upon terrain, may not be good. But I can never walk away without at least trying. Do that, before you put out the big bucks to buy a new one. You might get lucky.

[kelpdiver 2]

Quote

Using a map....
Place a dot where your exit point was.
You lost it at 14,000'
Now, draw a line from the exit point along the wind line for the day for 28,000' (about 5.3 miles).
From that same dot, draw two parrellel lines on either side of the first line about 15 degrees from the now center line for the same distance, giving you an expanding range from 30 degrees to about 45 degrees at the furthest distance.
Then calculate the number of square acres within that vector fan for helmet exploration.
Now, take out your wallet and go buy another helmet.

and then drop it!

It will land next to the lost one.

[crotalus01 0]

Agree with JohnRich, you have to at least look. Last year we had a guy who lost his Dytter on opening (how I have no idea). We looked around the area below his approximate opening point (a cotton field). I actually stumbled across it by pure chance. It still worked too (maybe the cotton dampened the impact).

As for me and my house, we will serve the LORD...

[NWFlyer 2]

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Agree with JohnRich, you have to at least look. Last year we had a guy who lost his Dytter on opening (how I have no idea). We looked around the area below his approximate opening point (a cotton field). I actually stumbled across it by pure chance. It still worked too (maybe the cotton dampened the impact).

Just lost mine (at altitude!) this past weekend and it was found in less than a day with no damage to the helmet or audibles. Definitely have to look.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2861976

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke