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schon267

wind

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question,
why do tandums still jump in winds that ground students (gusting to 20 mph )? I realize that the tm has loads of experience, but a lot of licensed skydivers don't go in these winds either.
is it because there is more weight with tandums? and what size canopy does better in the wind? bigger or smaller??
what dangers exist in these type winds?
thanks for helping the new guy with these questions!!

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It can also have something to do with forward movement. Can an instructor and TI please help me out on this, however this is what I remember being told:
canopies have a certain forward speed and if the winds go over this speed, there is a good chance that the student will be travelling either backwards or at least not forwards as they approach to land. Chances of injury are higher in that event.
tandem canopies *may* be designed with a different 'natural' forward speed and can therefore avoid the going backwards stuff up to higher wind speeds.

I may be completely wrong on this - so please correct me if I have mis-understood this stuff. I'm no TI or other instructor, nor a canopy designer. I just wanted to give the DZ's the benefit of doubt that it isn't all about money

tash
Don't ever save anything for a special occasion. Being alive is a special occasion. Avril Sloe

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question,
why do tandums still jump in winds that ground students (gusting to 20 mph )? I realize that the tm has loads of experience, but a lot of licensed skydivers don't go in these winds either.



Money:P (and experience and sometimes foolishness)

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is it because there is more weight with tandums? and what size canopy does better in the wind? bigger or smaller??



Ok, this is a good lesson in wing loading, ground speed vs. airspeed (determined by wind), penetration, glide slope, etc...

I don't know what you know about these subjects, but once you have a handle on each one of them, you will be able to answer your own question... So, you can ask your instructors, read some good books (Brian Germain's "The Parachute and It's Pilot" comes to mind), or search these threads...

Sorry to send you off on a search, but learning never comes easy, but you will learn more than if I gave you a quick run down...

But, real quick... What do you think the wing loading of a tandem is? The Sigma canopy comes in 370 and 390 sqft. Lets say you have a TM that is 180 pounds and a 180 pound student. Add 60 pounds for gear. So what is the wing loading???

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what dangers exist in these type winds?



  • Landing backwards (no penetration).
  • Being pulled across the ground after landing.
  • Turbulence/rotors off of buildings/objects.
  • The "delta" or "change" in wind (gusts) can collapse a canopy or cause it to be difficult to control

    Oh, and I personally have found I am much more concerned in the CHANGE in wind instead of the speed of the wind... Change can be either direction or speed... So in your post when you said "gust to 20", what was the baseline, 15 or 5???
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    Okay... so now that I've gone back and read the thread again... the question was posed as to the baseline winds. If it's 15-18 gusting to 20... I'm there, been there.

    So to the first poster, my apologies. A lot of it has to do with a TM's feel for the canopy and their weight-loading. I do lots better on my 365 almost maxed out (~1.3) than a tandem pair that's half my weight in the same wind scenario. In fact, if I carve the turn a little to generate more speed on landing, I won't feel a 5 mph gust.

    Again, my apologies for reading that wrong.
    Nobody has time to listen; because they're desperately chasing the need of being heard.

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    1.07 wingloading with a 390 sq ft canopy tdog.

    I understand the wingloading, but if your jumping in the winds I described (gusting to 20, the low side was 5 mph, so 5 mph gusting to 20 mph) what canopy size will handle that wind better?
    the bigger canopy seems to me like it has more area to be pushed around, the smaller canopy seems like it would knife through the wind better without being pushed around??

    thanks for the replys! just trying to learn

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    1.07 wingloading with a 390 sq ft canopy tdog.

    I understand the wingloading, but if your jumping in the winds I described (gusting to 20, the low side was 5 mph, so 5 mph gusting to 20 mph) what canopy size will handle that wind better?
    the bigger canopy seems to me like it has more area to be pushed around, the smaller canopy seems like it would knife through the wind better without being pushed around??

    thanks for the replys! just trying to learn



    If the gust is from 5 to 20, I don't think I would be skydiving regardless of canopy... But, I think if I had already left the plane, I would prefer the larger canopy simply because if the stuff hit the fan it would be more forgiving... But I am a novice.:P

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