A method of detecting a change in fly-height comprising measuring a first baseline position error signal (PES) at a first diameter on a disk, measuring a second baseline PES at a second diameter, measuring a first transient PES at the first diameter subsequently to the first baseline PES, measuring a second transient PES at the second diameter subsequently to the second baseline PES, determining a first change in PES by comparing the first transient PES to the first baseline PES, determining a second change in PES by comparing the second transient PES to the second baseline PES, performing responsive action when one of the first change in PES exceeds a first threshold and the second change in PES exceeds a second threshold, and generating a general error condition when both the first change in PES and the second change in PES exceed respective thresholds.