(n.) In computing, a head crash means a serious disk drive malfunction. A head crash usually means that the head has scratched or burned the disk. In a hard disk drive, the head normally hovers a few microinches from the disk. If the head becomes misaligned or if dust particles come between it and the disk, it can touch the disk. When this happens, you usually lose much of the data on the hard diskand will need to replace both the head and the disk. For this reason, it is important to operate disk drives, particularly hard disk drives, in as clean an environment as possible. Even smoke particles can cause a head crash.
Head crashes are less common for floppy disksbecause the head touches the disk anyway under normal operation.