A projection of annual increase in air traffic of 4% to 2020 will exceed current capacities within a decade. Air traffic controllers are greatly challenged to handle this growth in air traffic on present approaches. Automation aids via new technologies and procedures are being developed to assist controllers to better monitor the air traffic and make decisions accordingly. Even so, air traffic controllers may still lose their situational awareness by failing to observe the appropriate flight parameters or data within the tactical control timeframe. Such problems are further compounded owing to the fatigue of controllers in an increasingly forseeable congested airspace. This paper presents a proposed approach via a real-time bio-signal interface of radar controllers, where their visual monitoring behaviour and mental workload is captured during tactical control. These data are then processed and converted into eye tracking metrics and Electroenchepahogram (EEG) workload levels which serve to guide and alert controllers on their active monitoring engagement with the traffic situations on display. Preliminary tests revealed that the approach is able to time stamp, track and replay the eye movement location accurately to within 0.5 degree angular deviation on 2K monitor display while assessing the mental workload during every second of operation. On number of eye fixation counts, gaze duration and EEG workload levels, noticeable difference in their monitoring behaviour when dealing with varying traffic flow at crossings could be observed.