PPRuNe Forums - View Single Post - Cirrus descent rate under parachute less with wind?
Old 4th Sep 2021, 05:40
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B2N2
 
Join Date: Dec 2001
Location: GA, USA
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Alright now that my brain is bleeding let me suggest the following;

You’re flying something like the Space Shuttle and you have a approach speed of 340kts.
Your rate of descent for a 3 degree (ILS) approach would be 1700 fpm.
You’re sitting there with a big grin on your face and you forget to flare.
You’re going to hit the ground at 1700 fpm no doubt about it.
That’s a hard landing inspection.
Now you’re in a Cirrus under the chute during the end of days and you’ve got a 340 knot wind.
You’re going to hit the ground with a vertical speed of 1700 fpm.
Now with a more realistic wind, 30 kts all the way to the ground, VS 1700fpm.
Just a steeper angle of impact all the way to vertical when the wind is zero.

As far as total impact energy of a combination of forward and vertical speed which is a glancing impact:



Like the age old joke: it’s not the fall that kills you it’s the sudden stop aka deceleration rate.

Last edited by B2N2; 4th Sep 2021 at 06:33.
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