In reply to Daniel Armitage: I managed to come off the very to of No.2 gully on the Ben last year whilst chopping a slot in the cornice. The last pro I had in was a screw a heady 40m below, so yes i fell 80m. Although it wasn't a full parabolic arc through space, I was going at a fair old speed and spent quite of bit of time in the air (so my partner told me anyway, as I cleared him with plenty room to spare). But anyway, the screw (that was placed in an snow covered boss of ice) held. Not to be recommended, and it hurt quite a lot, but at least I can still tell the tale. And it goes to prove that screws can be pretty bomber.
For all you gear spods it was a medium (17cm?) Grivel 360, and it had a DMM shock absorbing sling on it, with one Beal Iceline climbed in to it.