Flight crew reported they taxied onto runway while another aircraft was on final approach causing a ground conflict. The pilot immediately departed the runway due to the incursion.

Narrative

At SGU airport; aircraft taxied out to Runway 01 via A Taxiway. Departing chocks; a taxi intention was broadcast. No other aircraft broadcasts were heard during the taxi to Runway 01. Holding short of Runway 01; on A5; we proceeded with our normal pre-takeoff below the line checklist. Upon completion; airspace was visually cleared both left and right and the final broadcast was made expressing our our intention to depart to the north. No other broadcasts were heard at this time. Upon entering the runway; it was immediately noticed that there was oncoming traffic landing to the south on Runway 19. The pilot flying immediately departed the runway; avoiding any further hazard. The nature of the incident caused an immediate reaction to confirm the radios volume frequency and designated broadcast radio. This aircraft normally operates on the number 1 radio for broadcast. It was then identified that radio number 2 was being used to broadcast and receive; thus disabling our ability to monitor airport activity despite the crew having made all the appropriate broadcasts. Being at a low density; uncontrolled airport; made the prolonged silence between our broadcasts not unusual; especially since we had no visual of any aircraft in the pattern or on approach. A significant contributing factor was a CRM issue where preferential radio selection for broadcast created ambiguity. The takeaway on this for the crew has been to enhance CRM; specifically around radio procedures and communication.