Originally Posted by
Jonzarno
Kinetic energy is proportional to the square of velocity so it's actually more like nine times the energy (ca 17 KTS under the chute vs ca 50 KTS for the ditching)
As I understand it the actual conditions were winds of 28 knots and seas of 6-8 feet: not easy to judge a ditching.
I know, that’s why I used 25 knots vs 40 knots
The landing we observed was at 25knts (the wind was 25-28 so I used the lower number)
A C172 ditching in low wind (10 knots in my example) would be a landing at 40 knots (allowing for 10 knot reduction by landing into wind)
(40/25)^2 = 2.5 which is the times the energy when ditching a non-parachute aircraft in benign conditions vs the conditions in which this aircraft ditched. Hence, my peference to be coming down on a chute in anything other than winds over 30 knots (as the SR22 would probably be closer to 60 knots at touchdown)