The environment and circumstances surrounding aircraft moving about on the ground at an airport is nothing short of puzzling. An almost random mix of legacy technology and procedures and state of the art innovation, an airport is a place where aircraft, already out of their element, meet special challenges and unique dangers.
On average, there are in excess of two noteworthy runway incursions in Europe every day. Yet, even at the few places they have been implemented, we are still working almost exclusively with systems that warn of impending incursions in the control tower rather than directly in the cockpit! Strange thinking that stems mainly from the cost of equipping aircraft with means of receiving the information carrying the warning directly in the cockpit…
But moving further in from the runway, negotiating the taxiway system is no easy task and some airports, like Paris CDG or Chicago ORD, are notoriously difficult to taxi on due to the complexity of the taxi routes. While most of our cars are equipped with on board navigation systems that can take us to specific house numbers in most big cities, pilots still rely in most aircraft on paper charts and blue, green and red lights and taxiway markings and signs to find their stand. At least things are slowly changing in this respect and aircraft costing hundreds of millions will finally get the ground navigation capability cars have had for almost a decade now.
If we move a bit more towards the terminal, we cross an important boundary. The runways and even the taxiway system are under the purview of air traffic control at most airports (though this is not universal and there are places where the taxiways are actually under the control of the airport itself). The aprons on the other hand are the domain of what is commonly termed “ramp control”, usually run by the airport.
In this article we will cast an eye on this critical and often messy area to see what is cooking there to make airline operations more efficient.
The apron is unique in as much as multitudes of aircraft are parked there, surviving on ground power and surrounded by people and ground service vehicles, all rushing to the moment when the doors are finally closed and they are ready to start engines for the next flight. There is also a constant stream of arriving aircraft keen to move into empty or just vacated stands to start their own process of turnaround.
Traditionally, the organized chaos around the aircraft was being run by the handling companies active on the airport, the aircraft first asked clearance to push and start from ATC and then talked to ramp control until reaching the taxiways. All this time, the airlines, through their AOCs, were trying to keep track of what was going on… often with little success. The picture that emerged here was a bleak one. Take any aircraft and in turn it was being herded left and right by ATC, by ramp control, by the handling company… all the time with the airline hoping that it would still fit into the carefully balanced schedule they built up months earlier. The icing on the cake was the fact that these players, all convinced they were doing the right thing, most of the time did not talk to each other. They all had their information, were all convinced that the information was correct, and they all made the necessary decisions which, often, made things worse. But because they still did not talk to each other, the adverse effects of the decisions went mostly unknown to the makers of the decision driving only the others, downstream, to desperation.
One glaring example of this was evident in the past in Atlanta. When Delta aircraft pushed back in the narrow corridors between the terminals, the ground crew had no idea which runway the aircraft would take off from and so in a huge number of cases the planes ended up with the nose pointing in the wrong direction. They could still taxi out of the corridor and to the runway, but the distance and corresponding time was much longer than would otherwise have been the case. The situation was solved in the end by a new telephone line between the FAA tower and Delta (paid for by the airline because the FAA did not have the budget…).
This was in fact one of the very first “successes” of what came to be known as CDM or Collaborative Decision Making. In CDM, all the partners mentioned above are encouraged to share their information in order to build common situational awareness and ultimately make decisions together, fully aware of the consequences and impact of each decision on their respective operations. CDM information sharing and the better decisions it entails have shown its value many times. It is also important to note that CDM’s simplicity and cost effectiveness comes mainly from the fact that the partners are asked to share information they already had but failed to show to their partners. Hence the investment required was modest and the returns almost immediate.
One of the ways the FAA in the United States went after reducing runway incursions and generally increase the situational awareness of aerodrome controllers is the introduction of ASDE-X. ASDE stands for Airport Surface Detection Equipment, Model X. It is the most modern version of the airport ground surveillance radar still used in many places. Built by Saab Sensis, ASDE-X is much more than a radar, of course. It has the ability to fuse information from all current surveillance systems, like radar, multi-lateration and ADS-B. What is more, it covers not only the airport surface but also the terminal area. ASDE-X provides a comprehensive, highly accurate and real time digital picture of all aircraft and vehicle movement in its area of coverage. This digital picture can be used not only to generate a visual representation of the traffic situation but also as input to various tools that improve safety. These include runway incursion prevention modules.
That information has tremendous value is not a new discovery. However, with practically the whole surface of certain airports being covered by ASDE-X type surveillance, airports, airlines and third party companies suddenly realized that this information, fed into clever algorithms, can be used not only to enhance safety but also to enable a quantum jump in ramp operation efficiency.
Like with the original CDM concept, here again the new functions are being built on information that is already available (surface surveillance) and hence the investment required for new, innovative uses is very modest. The FAA has a huge role in this equation: they provide the ASDE-X output even for value-added company use completely free of charge!
In the past, output from a surveillance system would end up as a visual display and humans would be expected to interpret what they see and then make decisions on what they understood what the situation was or was going to be. In to-day’s highly competitive environment, where cost saving is at the top of the list of every manager, the requirement is very different. Surveillance data must be fed into a black box that is aware of company policies, business priorities and processes, general constraints and what have you, with the black box spitting out not pretty pictures but decision support information that help make the business run smoother and more cost efficiently.
Companies like Saab Sensis, Passur Aerospace and Metron Aviation are in the business of building such black boxes and selling them or their output to airlines, airports and handling companies.
Passur Aerospace has chosen an interesting approach to draw users to their products. AIN, or Airport Information Network is a free, net-based service and it has been developed to collaboratively manage diversions, tarmac delays and field condition changes. The launch airlines were Alaska, American, Delta, FedEx, JetBlue, United and US Airways. With 94 airports participating in the AIN, it is probably one of the biggest free service of its kind. Of course Passur is hoping that organizations using the basic services provided free in AIN will also visit the for-fee offerings which are, of course, the main source of their revenue stream.
Of course AIN is not the only game in town. Saab Sensis has Aerobahn and Metron Aviation is also in the running. Common among them is that they use surveillance data and process it via powerful business algorithms into innovative decision support information that is tailored to the specific needs of the company concerned at the location specified.
Although these new tools are not automatically linked with the idea of collaborative decision making, they in fact continue the same tradition. Use available data for best effect and work together for increased efficiency. The fact that the value-added companies ask money for their products is not against the principles of CDM. There is a clear business case for these services and there are many takers already.