This study demonstrates the effect of flying height variation on the offtrack data error rate. The experiments completed for this study employ a narrow track Winchester-type Mn-Zn ferrite head and are performed on a single disc spinner in a clean room environment. The variation of the flying height is accomplished by mechanically rippling the disc (artificially warping the disc via specially designed wavy clamping washers) at various frequencies. It was determined that increased flying height variation reduces offtrack data handling capability. Further, the amount of reduction depends primarily on the amplitude of the flying height variation.