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Coexistence of Humans and Technology in Air Traffic Control
COEXISTENCE OF HUMANS & TECHNOLOGY IN AIR TRAFFIC CONTROL
zBy Yen-Chun Cheryl Chen, ROCATCA, TAIWAN
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When I was still a student at the aviation training institute in Taiwan (which was only about five years ago), I remember using paper flight plan strips to indicate the movement of the flights. The instructor was particularly strict on those basic moves, which have to follow the given clearance. For example, when you approve traffic to push back, you have to move the paper flight plan strip of the traffic to the left. If the traffic asks for push-back, but has to standby due to traffic, you move the paper strip to the right to remind yourself of the waiting traffic. When the runway is occupied either by the ground controller or by the tower controller, there will be a reminder strip put on the stripboard as a way for alarming the occupancy of the runway.
Soon after we left the training institute and were assigned to control towers for OJT, we realised the electronic flight plan system is used in the real tower operation, and we have to build up a new set of control habits. The advanced-surface movement guidance and control systems (ASGCM-S), which are called ASDE in the tower where I work (RCTP, the Taipei Tower), are used to provide better surveillance to the operational area. Although the surface radar can already provide warnings to controllers when objects are detected on the runways or to alert the controllers that the two traffics are potentially getting close to each other, it still requires the controllers to use their eyes to double-check the intruding objects and to use their experience to judge whether the two traffics will eventually get too close to lose the required separation.
After the old control tower of RCTP provided air traffic management services for nearly five decades, we moved to a newly built control tower right next to the old one. During the move, we also upgraded our control system to an advanced tower automation system (TAS). Similar systems have been installed in many modern control towers. The concept behind the system is based on the fact that the flight strips move in a flow that follows the journey of the flight from clearance at the delivery, to start-up and push-back with the ground controller, and to departure from the tower. When you finish one action, for instance, giving clearance, you press the bottom stating ‘CLR’, the electronic flight strip will be automatically transferred to the ground position. Similarly, when the ground controller clears the traffic to be pushed back, he or she will click the button stating “pushback,” the strip will then move to “taxi section” to wait for the taxi clearance. One of the advantages of this automation system is its ability to be integrated with ASGCM-S and to provide better detection of possible runway incursion caused by human errors.
How does it work? When traffic is cleared to line up, the runway will be identified as occupied; therefore, the action button "cleared to land" for the landing traffic and the action button "line up and wait" for the traffic waiting at the runway head will all be blocked. Likewise, when traffic is already cleared to land, the action button for "line up and wait" will be blocked automatically. When the traffic is holding in position but has not been given take-off clearance, and the landing traffic is approaching, the system will warn you with the awaited departure clearance.
On the visit to the Singapore Aviation Academy, the staff showed their tower and radar simulators. The simulators include a voice recognition function to identify voice clearance given by the controller and response to it. Although the success rate of the voice recognition is not yet 100% due to an insufficient voice database, the technology opens up the opportunity for future development in ASGCM-S. Imagine, when the ASGCM-S is able to recognise the taxi instruction given by controllers, it will be able to help detect whether the aircraft is on the right path and avoid potential traffic conflicts on the taxiway. Nevertheless, all these advanced techniques will only equip air traffic controllers with better situational awareness. They are not designed to replace humans as the main role in doing the controlling job.
Research has been carried out on how artificial intelligence (AI) can assist air traffic controllers in handling increasing traffic. Whether the computer can totally replace human brains in managing air traffic – similar to the discussion of whether there will be non-piloted passenger flights in the near future – have not yet had a promising prospect. As air traffic controllers, we all know that there are unexpected situations, and there are things, which can neither be quantified nor measured. These are exactly the moments where human experience and judgment have to intervene. At the ATC-Pilots Symposium in Singapore last year, Prof. Vu N. Duong proposed a hybrid human-AI system for air traffic control. This model stresses the cooperation between humans and AI that might provide an inevitable solution to increasing traffic volume in the foreseeable future. y
Photo: Philip Chang, an ATC at RCTP
