Head Crash

The phenomenon of a hard drive head touching the surface of the hard disk platter. Most hard disk heads “float” a very small distance above the disk. If something causes the head to touch the disk, the head, the disk surface, and more importantly your data can be damaged. This is a rare occurrence in modern hard disks, but back in the “olden days” even a minor bump to a spinning hard disk could cause a crash, which usually resulted in a total failure of the drive and extensive loss of data.