Heading Select Mode acquires and maintains the Selected Heading. The Selected Heading is displayed as a cyan bug on the HSI and shown in a box to the upper left of the HSI in cyan.

When HDG Mode is active and the HDG/TRK Knob is turned, the FD commands turns in the same direction as Selected Heading Bug movement, even if the bug is turned more than 180° from the present heading (e.g., a 270° turn to the right). However, changes of more than 330° at a time result in a turn reversal.

If HDG Mode is active and the aircraft is banking/turning to a Selected Heading when the Selected Heading is synced to the current heading, the Selected Heading and bug sync to the current heading but the aircraft continues to adjust/move as it rolls past the synced heading. In other words, the resulting Selected Heading will roll past the heading when the sync was initiated, overshooting the desired heading. The AFCS will roll back in the opposite direction to capture the desired heading.