Patent ID: 8169734

Claim:
A disk drive comprising: a measuring module configured to measure a flying height of a head with respect to a disk; a flying height controller configured to control the flying height based on a preset value corresponding to the flying height; a detection module configured to detect an environmental element value representing an environment of the head; and a controller configured to maintain or adjust the preset value in accordance with changes in the environment based on the environmental element value detected by the detection module, the controller being further configured to: maintain the preset value set before head switching, when the same head is selected again in an occurrence of the head switching, and subject to a first condition that the same head is selected again within a short time from last selection of the same head or a second condition that a change in the ambient environment is not more than a threshold value, and adjust the preset value of the head selected again, based on the flying height measured by the measuring module and the environmental element value detected by the detection module, if neither the first condition nor the second is met.