HDD producers implement a Fly Height Monitor that attempts to provide
additional protections for write operations by detecting when a
recording head is flying outside its normal operating range. If an
unsafe fly height condition is encountered, the write process is
stopped, and the information is rewritten or reallocated to a safe
region of the hard drive. This attribute indicates the count of these
errors detected over the lifetime of the drive.
This feature is implemented in most modern Seagate drives and some of
Western Digital’s drives, beginning with the WD Enterprise WDE18300
and WDE9180 Ultra2 SCSI hard drives, and will be included on all
future WD Enterprise products.
This parameter is considered informational by most hardware
vendors. Although degradation of this parameter can be an indicator of
drive aging and/or potential electromechanical problems, it does not
directly indicate imminent drive failure. Regular backup is
recommended. Pay closer attention to other parameters and overall