Method and apparatus for avoiding collision of head in disk drive

A disk drive is disclosed which provides a function of restoring a flying head to its normal flying state in the event that the head comes into contact with the surface of a rotating disk due to disturbance and if recovery from the contact state is allowed. When contact or collision of the head with the disk is detected by a collision monitor, a CPU determines whether or not recovery from the contact state is possible on the basis of the condition of disturbance detected by a sensor. The CPU, on determining that recovery from the contact state is possible, carries out a contact avoidance operation to restore the head to its normal flying state.