<div class="htmlview paragraph">Helicopter collision avoidance system (HCAS) is implemented under geodetic information system (GIS) environment for display. The conflict avoidance algorithm can be effective if the global system for mobile communication (GSM)-based automatic dependent surveillance (ADS) can provide sufficient data communication support. In this paper, the implementations of HCAS for the ground control station and for the airborne avionics are presented. Especially, the airborne display to suitable for pilots is concerned with real time solution. The airborne data of position and heading are fed into GIS mapping for flight situation awareness to all participating pilots and air traffic controllers. A route map is generated following a flight plan. Map rotation of airborne display based on each grid map center is proposed and implemented to offer pilots a good visual effect. This paper presents the overall conceptual verification of the proposed HCAS for practical applications.</div>