I used to fly R/C slope and F3B gliders and thought they went pretty fast... but 498?!!!

 

Google "speed record dynamic soaring". Most of the videos you can't see the plane very well but this one shows it pretty good and the sound is cool.

 

https://www.youtube.com/watch?v=DegX_we1Mic

 

I'll bet Lee knows about DSing. I did a little bit when this first became popular and it gets pretty scary! Imagine getting hit by one of these at speed! Like a 30mm from a Warthog probly.

That's crazy.

 

The wiki article on dynamic soaring is pretty good:

 

http://en.wikipedia.org/wiki/Dynamic_soaring

 

Had to look it up.