exit at 55mph

[TVHigley]

I need some feedback on the best set-up, and the best way to aproach the jump.--
I will be exiting from a truck moving at 55mph. It is 170 feet to impact. With the parachute inflating horizontal to the ground, would an off heading opening be disaster(packed slider down)? At that speed, would it be best to pack slider up? Any and all feed back will help.
-TODD

[Mike]

55 mph is roughly equivalent to a 3 sec delay. You don't need a slider, but it might help delay your opening just enough to put you under the steel in case you have an off-heading. It may also dampen some of the oscillation that would occur from a nearly horizontal slider-off opening.

Either way I'd use a 42 and probably go stowed--wouldn't want to accidentally drop that pc too early. Allow for about a second delay to ensure a solid launch and square yourself to the relative wind. Try to be as head-high as possible if not vertical. You may want to practice clear-and-pulls at the dz out of the slowest plane they have, like an otter.

Most 170' spans I've seen don't span much. At 55 mph, you may have only a small window in which to spot yourself. A second too late on the exit and you will be 80' closer to the side of the gorge. Better check on that.

[motherhucker]

I would vote for slider off and taking a [horizontal] delay in the 2 range--as mentioned above though, make sure you spot it right.
good luck.

[crwper]

Keep in mind, as with aircraft jumps, your airspeed may actually DECREASE in the first couple of seconds.

Drag is roughly proportional to the square of velocity, so the faster you are moving, the faster you will decelerate due to drag. It's not too hard for this deceleration to become greater than your acceleration due to gravity, leading to the result -- well known to anyone who's done a lot of hop 'n pops from aircraft -- that you may get a softer opening with a couple seconds' delay than with a clear-and-pull.

Michael