some emergency parachutes "can be" fitted with square (ram air) parachutes,
these are only for certified jumpers who have experience in this type of
parachute. However, it also should be noted that square parachutes do not
function like round or conical parachutes, they don't open reliably unless
you are in a stable position, something you likely will not be in
immediately after a bail out and may never be in if you're not an
experienced jumper, more likely you will exit and emergency bail out
tumbling and even with experience you may be disabled and unable to enter
into a proper PLF position for deployment. The standard round canopies used
in most emergency parachutes are extensively tested to open for all
positions, in all imaginable conditions, even soaked wet, mispacked or
other... the landing with a ram air parachute is also much like
flying....they can be flown very fast, slowed, even stalled (though for
emergency use they would be less controllable to limit these) you need to
learn to flare at the correct time to make that soft airshow like stand up
landing, otherwise your landing can be pretty eventful.....(ever notice how
many at the local jump site are wearing casts or walking with crutches? )
So IMHO and in the opinion of most manufacturers the ram air canopies have a
place, but not typically in emergency pilot rigs.
Tim
Please visit the Wings & Wheels website at www.wingsandwheels.com

"Eric Greenwell" wrote in message
news:jQwDj.8843$2Y4.6839@trndny01...
Jim Meade wrote:
I'm looking at a parachute for a glider. Would like to use it for
other flying, as well, if it is suitable. INo clue of the advantages/
disadvantages of any of them.

A friend of mine is also looking for a new parachute. He is considering a
new type of emergency parachute that is rectangular ram air design, like a
sport parachute, but does not require the training that a sport parachute
does. I believe this is the one:

http://www.parachuteshop.com/aviator..._parachute.htm

Scroll down about one page to the section labeled "The canopy".

The main advantage seems to be a lower descent rate of 12 feet/second, vs
the standard round emergency parachutes that have 18 feet/second. My high
school physics says it's about the difference between jumping off a 2.5
foot high ladder vs a 5 foot high ladder.

Any comments on the desirability of this new design compared to the round
parachutes we use now? Is the lower descent rate ever a liability; e.g.,
in updrafts near a cloud? Does the lower descent rate also mean you might
dragged more after landing in windy conditions?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org