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From: galperin@husc9.harvard.edu (Gregory Galperin)
Newsgroups: rec.skydiving
Subject: Re: Differences between parachutes and paragliders
Summary: The two are diverging rapidly
Keywords: parachutes paragliders
Message-ID: <1991May1.212459.776@husc3.harvard.edu>
Date: 2 May 91 01:24:58 GMT
References: <6435@qip.UUCP>
Sender: galperin@husc9.harvard.edu
Organization: Harvard Mountaineering Club, Massachusetts Sport Parachute Club
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In article <6435@qip.UUCP> bobm@anasaz.uucp (Bob Maccione) writes:
>i tried to explain that they aren't the same and am wondering if anyone out
>there in netland knows the difference between [parachutes and paragliders]...

	Paragliders originated in mountaineering/climbing as an easy way of
descending from a lengthy climb (and in more than a few cases they saved at
least some fingers and toes when conditions turned sour).  Climbers rigged
7-cell ram-airs up to their harnesses and took a quick (and fun!) trip down;
just like in skydiving, the main goal then was to get back down to the ground.
	But since they hadn't just been in freefall for a mile ( ;-), a couple 
of minutes under canopy on the way down didn't provide enough excitement.  So
they started using larger and larger canopies, with more and more cells...
all the time looking enviously at hang glider pilots above them.  The designs
grew in wingspan and area continually, and many paragliders are now over
40 ft. in wingspan and 450 sq. ft. in area, with a large aspect ratio.  The
resulting airfoil is something like a ram-air sailplane (i.e., parachute +
glider = ...), and flies something like a hang glider (or so I've been told,
at least).  The chord length tapers off severely at the ends, and the last
few cells are closed in front (they have no ram-air port, only cross-ports),
and curve down like stabilizers.
	It's true that the materials used in paragliders are generally less
porous than those in skydiving canopies (although it's hard to get less
porous than a zero-porosity fabric... :), but a greater difference is that
paraglider materials are less elastic (which is why an opening shock from
terminal would shred them).  Even standard parachute line cord has too much
stretch for paragliders (I know someone who injured himself when he rigged
his 'glider up with standard jacketed suspension line and couldn't control
it enough to keep from stalling out).
	These canopies allow a much greater glide ratio than parachutes, and
allow (good) pilots to stay in the air for hours.  Anyone who's been hanging
in a harness for over 15 mins. can understand why paragliders grew seats as
they became larger; multiple line groups are connected to the seat along its
length so that shifts in weight can steer the paraglider.  To stay flying,
'glider pilots catch thermals (and carry variometers to help find them).
'Glider competitions sprang up, and have categories much like glider 
(sailplane) competitions: net distance, time around a course, etc.
	In summary, you can still buy small (<5 lbs!) 7- or 9- cell
paragliders to use for descents (and this is standard equipment for climbing
in Europe), or you can go the competition 'glider route.  They're probably
more expensive than "normal" 'chutes because (1) they're larger, (2) the
designs are more complicated (tons o' cells, tons o' lines, and a more
involved airfoil design), and (3) the market is still relatively small.

Have I rambled long enough yet?-------+
                                      !
                                      +------=> Greg Galperin
                                                galperin@husc9.harvard.edu
                                                Harvard Mountaineering Club
                                                Mass. Sport Parachute Club