Darwin Approach controllers were routinely exposed to green (limited data block) radar returns that were generally inconsequential in that Approach control environment, leading to a high level of expectancy that such tracks were not relevant for aircraft separation purposes. Refresher training did not emphasise the importance of scanning the green radar returns.
Response to safety issue:
In response to an internal recommendation for the Department of Defence’s 44 Wing to review radar control training programmes to ensure that they include a requirement for controllers to scan green codes, the Department of Defence (DoD) documented that:
The School of Air Traffic Control stated that they concentrate quite a lot of time towards scanning of green codes during the Initial Employment Training and the Approach training.
Planner students are required to continuously scan all unidentified aircraft to expand on their situational awareness. The subject of violations of controller airspace is also touched on with emphasis on the crew resource management aspect of scanning and assisting the approach controller in monitoring airspace.
During Approach training, unidentified aircraft are actively input in the scenario as violations of controlled airspace adding to the requirement of the controller scanning the radar picture. To ensure a non-standard solution, the exercises have multiple unidentified tracks outside of controlled airspace which never actually enter the airspace.
In addition, DoD documented that the majority of simulator-equipped air traffic control units had included green radar returns in their local training packages. The scenarios included unidentified radar returns that entered controlled airspace, with some requiring a traffic alert to be given and an ‘alternate separation solution implemented’.
The ATSB is not yet satisfied that the action taken by the Department of Defence has addressed the safety issue. Though the consideration of controller scanning of green radar returns has been covered in the initial and approach training syllabus of the School of Air Traffic Control, and included in the simulator scenarios of the air traffic units where there is such a capability, there is no evidence that there are provisions at those units to ensure that controllers complete the simulator-based refresher training. In this occurrence, the Darwin Approach cell personnel on duty reported that they had not completed any refresher training in at least a 12-month period, though Darwin was simulator-equipped.