In a method of head-disk contact detection in a hard disk drive, a Radio Frequency (RF) carrier signal is injected into a slider which is flying above a surface of a disk in a hard disk drive. A modulated version of the RF carrier signal is received from the slider. The modulated version of the RF carrier signal is demodulated to achieve a demodulated signal. A signal spectrum of a range of frequencies in the demodulated signal is monitored for activity indicative of a contact between a head of the slider and the surface of the disk. An occurrence of the contact is determined based upon an occurrence of the activity.