1. A method used by a servo system for a hard disk drive to control the track alignment of a transducer head relative to a desired tracking location comprising: measuring track alignment using servo data position error signals (PES) read from a rotatable disk by the read head; measuring a feed forward signal indicative of external disturbances applied to the hard disk drive; and determining track alignment using the PES measurement and the feed forward signal measurement, the feed forward signal measurement being used to determine corrections only when the servo system determines use of the feed forward signal reduces track alignment error.