emergency chute

How does a square know which way the wind is blowing?

I'll buy the rest of the argument for a square reserve (having a few
jumps, both static and freefall, under old military rounds), but I have
a hard time understanding how a free falling object can orient itself
with the wind - unless it is big enough (tall enough) to be affected by
wind shear.

Explanation, please?

66

OK, given the preference of those who know more than I do, I have to
ask the obvious question: Why are there still round chutes? If I order
a National or Softie from my local glider haberdasher... won't I get a
conical? I'm not disagreeing with the assessement of thems that knows.
But I would like to understand why we haven't seen a wholesale
conversion to the square.

Not a troll... though it has the earmarks, doesn't it?


wrote:
snip Would that mean that the passenger should have a round chute
and
just accept their lumps, so to speak? /snip

Colin: Yes, exactly.

OC: as the unidentified rigger said, the square. The chances of the
pilot being dazed and confused to the point of not even being able to
find and operate the brake/steering toggles are small, and if unable
to
do so by injury or unconsciousness, I would still rather be under the
square.

2NO

fiveniner: it's simple. The round chutes are cheaper and require no
training (a lot less, anyway).

I *am* surprised, however, that the square chutes aren't a tad more
popular than they are. That's probably because of a simple lack of
knowledge and the institutional momemtum of using rounds/conicals for
so many years...

ted/2NO

66: not very many skydivers share this opinion (that squares turn into
the wind). I experimented with the theory a half dozen times when I was
jumping solo and not once did the canopy ever turn into the wind.

2NO

Reliability. Perhaps you should ask the experts on
emergency egress, in the case of the UK it is a company
called Martin Baker. Ask them how many of their seats
use square chutes. A canopy capable of opening safely
at the sort of speeds involved in ejections is good
enough for me.
If sport chutes are so reliable why do sky divers have
a reserve?

An emergency chute is designed to work even under adverse
conditions. A sport parachute has a completely different
design concept.


At 12:04 06 April 2005, wrote:
OK, given the preference of those who know more than
I do, I have to
ask the obvious question: Why are there still round
chutes? If I order
a National or Softie from my local glider haberdasher...
won't I get a
conical? I'm not disagreeing with the assessement of
thems that knows.
But I would like to understand why we haven't seen
a wholesale
conversion to the square.

Not a troll... though it has the earmarks, doesn't
it?


wrote:
Would that mean that the passenger should have a
round chute
and
just accept their lumps, so to speak?

Colin: Yes, exactly.

OC: as the unidentified rigger said, the square. The
chances of the
pilot being dazed and confused to the point of not
even being able to
find and operate the brake/steering toggles are small,
and if unable
to
do so by injury or unconsciousness, I would still
rather be under the
square.

2NO

To Fiveniner: you can buy directly from Softie a square emergency
parachute.

To 66: it is called weathervaning...go and make a jump, don't release
your brakes and see what the canopy will do. Especially the big ones
like Raven IV.

To Eric Greenwell: no it doesn't work like that. Round/conical will
descent at that rate no matter what. There will be a small difference
in descent rate between suspended loads (heavy pilot versus light
pilot) but not a really significant number. If you would like I can
swing by the airport and drop you a book with explanations about
parachute desingns. I don't want to type the explanation because would
be to lenghty.

Yeah, thats the idea...use Martin Baker 0-0 seat and you have no issues.

wrote:
To Fiveniner: you can buy directly from Softie a square emergency
parachute.

To 66: it is called weathervaning...go and make a jump, don't release
your brakes and see what the canopy will do. Especially the big ones
like Raven IV.

You need a relative difference in speed to the wind to weather vane. An
uncontrolled parachute would match the wind speed as it descends. As
you drop through the typical wind shear near the ground, it seems to me
that you would turn to land down wind if you didn't actively steer the
chute.

Shawn

Don: Don't confuse "square" with "sport". Emergency/reserve "square"
parachutes are designed very differently than their main/sport
counterparts. Also, skydivers use a reserve for two reasons: (1)
main/sport parachutes are designed with flight performance as a major
design criteria; they are very reliable but not as reliable as
reserve/emergency chutes. (2) The FAA prohibits intentional parachute
jumps without a reserve. (3) It would be really dumb anyway

2NO

Aren't most BASE jumps done without a reserve? Do BASE jumpers prefer
the reserve square or the sport chute (since control into tight LZs is
a consideration)?

Just trying to get educated since we appear to have a group of folks
with useful information.