"Eric Greenwell" wrote in message
news:BlFDj.8407$dq2.489@trndny05...
Capt. Geoffrey Thorpe wrote:
"Eric Greenwell" wrote in message
news:jQwDj.8843$2Y4.6839@trndny01...
...
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.


I _assume_ a better comparison would be jumping off a stationary 5 foot
ladder vs. jumping off a moving pickup truck?

I'm not sure what you mean, but what I was trying to say is a 12
feet/second descent rate is how fast you are moving after jumping from a
2.5 foot high ladder, etc. Any horizontal motion would depend on the wind
strength and which direction you were pointed relative to it.


A round 'chute doesn't fly with much horizontal velocity, but my
understanding is that for a ram air chute to work, you do need quite a bit
more forward speed to keep it inflated and to keep the descent rate under
control - hence, while the verticle velocity may be lower for the ram air
chute, I suspect the horizantal velocity will be much higher - I don't know
what the total velocity (vector sum of the horizantal and verticle) would be
for one vs. the other.

Please correct me if I am misunderstanding something.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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