[RightWhale]

the whole idea about the Winchester drive that a cushion of air prevented the heads from ever touching the surface

Yeah. The head can bounce anyway if the harmonic mode is out of balance, and it can happen even if the box is stationary.

[djf]

I had head crash on my laptop. Lost some important emails.

The one thing I learned was if you get a head crash, don't screw around with it. Rescue everything off the disk as soon as possible, then chuck the thing.

A crash will wipe out a few sectors, yeah. But it causes tiny bits of the disk media (hopefully, not the heads themselves) to come lose inside the drive.

So now you have your own personal sandpaper floating around inside your drive. It's only a matter of time before it decides to randomly start wiping out other areas.