Magnetic disk device

A magnetic disk device comprising:

• a magnetic disk;
• a magnetic head that includes a write head configured to write data to the magnetic disk, a read head configured to read data from the magnetic disk, and a heater configured to adjust a flying height of the write head;
• and
• a controller that includes a first detection unit configured to detect the flying height of the write head, a second detection unit configured to detect a positioning error of the magnetic head with respect to a track of the magnetic disk, and a memory configured to store a first threshold and a second threshold,
• the controller:
• supplying power of a predetermined power value to the heater such that the flying height of the write head becomes a desired flying height when data is written to the magnetic disk by the write head,
• detecting the flying height of the write head by the first detection unit,
• detecting the positioning error of the write head by the second detection unit, and
• increasing the power value of the power supplied to the heater in a case where the flying height of the write head exceeds the first threshold and the positioning error of the write head exceeds the second threshold,
• wherein the controller further:
• returns the power value of the power supplied to the heater to a desired power value,
• detects the flying height of the write head by the first detection unit,
• detects the positioning error of the write head by the second detection unit, and
• writes data to the magnetic disk by the write head in a case where the flying height of the write head does not exceed the first threshold or a case where the positioning error of the write head does not exceed the second threshold.