A recommendation: Go to an amusement park and practice solving on roller coasters. (Inspect while going up the first hill, then start solving at the top of the hill.) I've never skydived, but I have tried solving on a roller coaster, and I can tell you it's a LOT harder than a regular solve. (I didn't succeed the one time I tried it - I finished the LL after it stopped.) For one thing, you're scared to death you'll drop it. I'm sure it's not as difficult to hold onto the cube while skydiving as it is while riding a roller coaster, but I suspect the panic aspect will still be there, and that definitely will make it harder. Getting where you can comfortably solve a cube while riding a roller coaster will probably be a relatively inexpensive way to prepare so you can make sure your attempt is more likely to be successful.
I really hope you succeed!!! Is it true that you would be only the second person to do it:
http://www.speedcubing.com/records/recs_crazy_freefall.html
... or are there other people who have done it but not posted?
