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I want to know the difference between a paraglider and a parachute. Can you explain the difference between a paraglider and a parachute in general?

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    $\begingroup$ By 'hole' do you mean the cell openings on the leading edge of the canopy? en.wikipedia.org/wiki/Paragliding#Wing $\endgroup$ Commented Mar 5, 2022 at 18:45
  • $\begingroup$ @MichaelHall: On the other hand, modern ram-air parachutes have more in common with paragliders than with the traditional "military" round/cruciform parachute. $\endgroup$
    – Vikki
    Commented Mar 5, 2022 at 21:34
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    $\begingroup$ By "parachute" do you mean an old-style round parachute with a vent hole on the top, or a square ram-air parachute with ram-air holes along the leading edge? $\endgroup$ Commented Mar 6, 2022 at 20:52

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A paraglider is an inflatable wing pressurized by the dynamic pressure at its leading edge openings, that makes lift and glides like any other wing, whereas a parachute with a hole in the center is strictly a drag device designed to operate at a 90 degree angle of attack and doesn't produce lift.

The hole is there to allow air trapped by the down velocity of the canopy to vent out the top instead of spilling out the sides. This reduces its tendency to swing. Putting vent holes at one location at the edge of the canopy generates a slight forward thrust that introduces a bit of glide, and pulling down the center with additional center suspension lines reduces the frontal profile and improves glide further.

The Paracommander was the ultimate circular canopy and used additional directional venting at the top, with a pulled down center to reduce the frontal profile. Those canopies are a little bit wing-like and have a better glide ratio than conventional round parachutes, maybe 1.2 to 1 (I used to jump one in the mid 70s).

Ram air parachutes are basically paragliders that operate with much higher wing loadings, fewer cells, and lower aspect ratios, with higher minimum speeds, with heavier lines and fabrics to tolerate opening shock at terminal velocity.

With modern zero porosity fabrics, ram air parachutes achieve glide ratios of up to 3:1, whereas paragliders are made with many smaller cells (to make the wing thinner), thinner lines, lighter zero porosity fabric, and have lower wing loadings with higher aspect ratios. That achieve glide ratios of around 6 to 10 to 1.

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The first paraglider flights were carried out on Ram air ‘square’ parachutes, and paragliders were then developed to have better flight characteristics. A parachute needs to have extremely reliable deployment, good stability in the air and a survivable descent rate, while a paraglider needs a good glide ratio, good airspeed and needs to be easy to fly (fatigue!) for up to several hours at a time. As a result, parachutes tend to have few cells, large cell openings and are made from strong but porous materials, while paragliders have many more cells, often more suspension lines, higher aspect ratio and are made from much less porous materials. Since paragliders are normally inflated on the ground prior to launch, slow inflation isn’t a problem and line tangles can be dealt with easily. In contrast, a parachute may be deployed with a very high airspeed where a line tangle is unacceptable and a non-porous paraglider would likely suffer serious damage.

In the early stages of paraglider development, aspect ratios were increased so much that when hit by a gust, the canopy would collapse from the center, like the closing of a book, resulting in several deadly accidents. Lower aspect ratios make the chute more robust against collapse.

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  • $\begingroup$ Nice answer! Last sentence, did you mean to say a non-porus parachute (not paraglider), or even the parachutist using it, would suffer serious damage, presumably at opening shock? $\endgroup$
    – Ralph J
    Commented Mar 5, 2022 at 22:39
  • $\begingroup$ @Ralph J I meant non-porous paraglider because that’s what they are but a parachute made of 80g non-porous nylon would fare no better. And yes the parachutist would not have a pleasant experience. In-air deployment using a paraglider is possible (d-bagging) but it typically done with the lowest possible airspeed and with the wing folded so that inflation is somewhat progressive. $\endgroup$
    – Frog
    Commented Mar 5, 2022 at 23:35
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    $\begingroup$ Earlier ram air parachutes and paragliders were made of a low porosity ripstop nylon fabric, and the newest ones are made from zero porosity ripstop fabric for improved performance. I used to own a ParaCommander round when I was jumping in the late 70s, and it was made of nylon taffeta fabric. $\endgroup$
    – John K
    Commented Mar 6, 2022 at 2:28

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