[QUOTE=RatherBeFlying;10738439]Horizontal velocity allows friction with the ground to dissipate kinetic energy at a gentler rate than happens with a completely vertical impact.QUOTE]
Ok I agree that if a Cirrus is coming down under a parachute with a 20 knot wind it would reduce the impact force on the occupants if it could go along the ground in the same direction as the wind for a bit after impact rather than coming to an immediate stop.
However if it is coming down with no wind at the same vertical rate surely the force experienced on touchdown by the occupants in a vertical descent would be less because you have no additional sideways kinetic energy to dissipate?