From: yzarn@lhdsy1.lahabra.chevron.com (Philip Yzarn de Louraille)
Newsgroups: rec.skydiving
Subject: Re: first timer questions
Date: 5 Sep 92 17:11:07 GMT
Organization: Chevron Oil Field Research, La Habra, CA.

In article <1992Sep4.153606.21835@ticipa.pac.sc.ti.com> rmfowler@landru.mtc.ti.com (Rex Fowler) writes:
>
>I'm about to take a 1-time tandem jump sometime within the next 
>two weeks.   I know there isn't much training since there will
>be an experienced pro attached to to me.  But, I would like to 
>know some general things about skydiving(in tandem), such as:
>
>	How popular is it?  Is tandem jumping a good thrill-seeker sport?

Tandem jumping is not really a "sport", unless you are a tandem
instructor. It is a method to introduce people to the pleasure of freefall
without having to worry too much about safety. Since it is fairly
expensive ($from 80 to 130, depending where you go), I know of no one who
jumps tandem regularly (unless you are a instructor!).

Most people who do a tandem jump and like the sport of skydiving will then
further their education with Static Line jumps or Accelerated Freefall
jumps. 
>
>	How dangerous is it?  

To be frank with you, your chances of dying on such a jump are not null.
It is not like flipping a coin, or even one in a hundred, or even a
thousand, but the statistics are in the 10,000 range...
Now, there are skydivers out there and who follow this net that might tell
you that this is a safe sport. Well, they are welcome to their opinions...

Should you try it? Definitely. Are there risks? Yes.
>
>	Other than the obvious, what type of injuries can result.  I
>	picture the landing as being really tough with 2 people strapped
>	together.

The parachute is extra large and the instructor is experienced so your
landing should be quite OK. Risks vary from eating dirt to breaking legs
or backs but this is very rare.

>
>	For $50 extra I can have the jump video taped.  Do the videos
>	turn out pretty good?

That would depend on the camera-person. Ask to see a jump filmed by that
person and you will see if you like it.
>
>	Approximately how high will I be when I jump?

Usually 12500 feet.

>
>	How far and how long will I fall before opening the chute?

It depends on dropzones, but usual parachute opening procedures for tandem
happen around 6000'. It is much higher than for regular skydivers, but
this gives more time for your instructor to react to opening problems if
there are any. You also get a long canopy ride which is quite enjoying.
So your freefall time should be around 30 sec.

>
>	I've heard someone mention that you reach a "constant velocity".  
>	I though gravity would accelerate you at approx 32 ft/sec^2.  
>	Does  gravity quit pulling after a certain speed?  What speed?

For a regular skydiver, terminal velocity happens around 12 sec after
jumping. Since a tandem "profile" is denser (more weight per surface area
for the wind to catch), it could take up to 15 sec to get to reach
terminal. Anyone else has more data?
And by the way, gravity does not quit pulling after a certain speed. What
happens is that friction with the atmosphere increases with speed, and at
one point, this frictional force equals that of the gravitational pull,
but in opposite direction. At that time, your velocity is said to be
"terminal".
>
>	Is there a FAQ for this group?

Yes, I have seen one (I think), but I do not know who publishes it, nor
how often, nor if there is a site you can ftp to to get it. I don't even
know if it is published in news.answers.
>

-- 
  Philip Yzarn de Louraille                 Internet: yzarn@chevron.com
  Research Support Division                 Unix & Open Systems
  Chevron Information & Technology Co.      Tel: (310) 694-9232
  P.O. Box 446, La Habra, CA 90633-0446     Fax: (310) 694-7709
Newsgroups: rec.skydiving