Imagine a world in which a ground handler knew with certainty the exact time an aircraft would touch down. Its gate arrival would be known with a precision measured in seconds, and any operational requirements would be at your fingertips, including the exact moment it had to leave the gate and be airborne again.
Airport Collaborative Decision Making (A-CDM) will make all of this, and more, a reality — at least according to its supporters. Airport CDM aims to improve operational efficiency at airports. In theory it will reduce delays, improve the predictability of events during a flight, and optimize the utilization of resources — both in the air and on the ground. There is a particular focus on turnaround times and pre-departure sequencing.
Information sharing is the cornerstone of the process. Creating a common situational awareness is the source from which all other ideas flow. It allows a clearly defined pre-departure sequencing, for example, which in turn allows the Target Start-Up Approval Time (TSAT) to be calculated.
A Target Off-Block Time (TOBT) is the next marker in the A-CDM concept. This generates a transparent take-off time, and provides air traffic management with a degree of logistical efficiency. More accurate take-off information means reduced apron and taxiway congestion and allows available slots to be used more efficiently, reducing the current need to allow for buffer capacity and slot wastage.
Once one airport has successfully implemented CDM, that airport is ready to connect to the Collaborative Management of Flight Updates, which takes into account all airports in the A-CDM “universe,” enabling air traffic flow management slots to become reactive.
The theory is developed enough for airports to be embracing A-CDM positively. In Europe, ATM provider Eurocontrol, the International Air Transport Association (IATA), and Airports Council International are all engaged in pushing the concept. In all, 32 European gateways are in various stages of A-CDM introduction, analysis, or implementation.
In Germany, early adopter Munich, which implemented A-CDM in June 2007 has reported position overlaps — delays waiting for a free parking stand — are down to just 2.1 percent while improvements in runway waiting time averaged almost 30 percent, down from 4.39 minutes in 2005 to 3.09 minutes in 2009. Over the same period slot adherence improved over 20 percent to 90.3 percent. Munich handles around 1,100 movements daily so the savings are significant.
Frankfurt Airport started an A-CDM trial in November 2010, and the “Airport CDM harmonization Germany” is being rolled out countrywide. This will facilitate the exchange of information and best practices between the various German CDM airports. Aside from Frankfurt and Munich, airports in Berlin, Düsseldorf, and Stuttgart are involved, as well as the German air navigation service provider, DFS. Hamburg Airport is expected to join the group in due course.
Capitalizing on the concept
Airport CDM is winning plaudits all over the world. In the Middle East, Dubai is also enthusiastically learning all it can about the concept.
Nick Moore, senior vice president, airline services, of resident ground handler, Dnata, says Dubai does not have CDM technology in place, but the strategic direction of both Dnata/Emirates and Dubai Airports is to fully understand and capitalize on the concept. It will form part of a groundbreaking “Hub-Matrix” project that aims to enhance efficiency across the aviation spectrum.
“CDM is a positive step forward as it brings all the ground activities together under one IT framework,” says Moore. “This technology was pioneered by ATC authorities who were looking at the best use of airspace. For the industry to work exhaustively towards the best use of its resources and to ensure the best customer service is the required outcome.”
Moore says Dnata has been involved in the feasibility study from the outset and a joint team has been in Europe looking at best practice. “The study is taking all parties in the same direction,” he notes. “Investment decisions will need to take place concerning operations control centers, technology and people, and a sensible resolution is expected to take place.”
Majed Al Joker, VP terminal operations, Dubai Airports, agrees that this will be a positive process for all partners. “We are looking forward to working with all stakeholders, including our ground handler, on this important project,” he says.
Ground handling benefits
Ground handlers should be interested. There are huge benefits on offer resulting from a more efficient use of resources. With far greater accuracy in timings, the redundancy required in ground services should be minimized, greatly reducing costs.
For example, a pushback truck is estimated to spend around 15 minutes with an aircraft when the actual process takes just five minutes. That’s a significant saving of two-thirds. It’s not just current costs that could be avoided. Future operational expenses — such as reduced staff and equipment costs owing to greater resource efficiency — are also on the agenda.
Of course, investment in the implementation of A-CDM will be required. Some studies suggest the IT cost for ground handlers at a single airport will be in the $200,000 range. But with savings to be made on every aircraft handling, a return on investment is surely in the cards, possibly in as short a timescale as two years and with a cost/benefit ratio average of nine to one according to the Transport Research Knowledge Centre.
Etienne van Zuijlen, program manager for Airport CDM at Amsterdam Airport Schiphol, says that without the active involvement of ground handlers, the missing link in the flight process between arrivals and departures could never be realized. Commercial relationships still have to be considered, however. “Since these are often in confidence, and therefore not known in detail to either the airport operator and/or the air navigation service provider, it is essential that sufficient CDM elements are reflected in the Service Level Agreement or commercial contract,” van Zuijlen suggests. “In some cases, this implies sharing the benefits of CDM in these new contractual arrangements, a lengthy task.”
The real deal
According to a common adage, if something sounds too good to be true it probably is. The question for ground handlers is whether the predictability A-CDM appears to offer is the real deal.
The concept is perfectly clear for a flight in isolation. Consider one common scenario. A five-minute delay occurs because of tarmac congestion or a no-show. The pilot announces he will make up the time and often does. But on arrival in the destination airspace there is a further delay because the gate is not ready or there is congestion waiting to land. All these mismatches can be resolved through A-CDM, because the problems will already have been automatically highlighted and alerts communicated to all partners for mitigation purposes.
But what happens with multiple flights, each with its own agenda? Some flights will be ahead of schedule, some behind. For air traffic management, keeping them all to the time specified by the CDM may prove impossible — an aviation Gordian knot to which there is no drastic Alexandrian solution. That will have a knock-on effect, which may result in ground handlers not quite achieving the levels of efficiency first envisaged.
Even if the platform still needs some of the kinks working out, Airport CDM looks to be the best game in town right now. “Aside from the upgrading of the existing Airport Operational DataBase and upgrading or establishing B2B connections with the internal planning systems of airlines and handlers, the only investment needed is creating awareness with frontline people,” says van Zuijlen. “This takes communication and training to drive the essential culture change, which in turn means positive leadership to demonstrate that sharing is beneficial to all.
“Cost benefit studies, supported by established implementation, have shown positive net present value within one or two years and a ratio of 1 to 10,” continues van Zuijlen. “There is much more potential to follow.”
In Germany, Munich is certainly committed to the benefits of the system and its future development. After two years of A-CDM, performance paybacks are being reported at both airport and ATC level, although experience in 2009 demonstrated a need to further develop A-CDM during winter severe weather operations.
Dnata’s Moore concurs that A-CDM has to be worth exploring. “Ultimately, any sharing of operational information in a collaborative manner is positive,” he says. “Here in DXB over the next 10 years there will be extensive investment in airport facilities to match the growth of Emirates airline and flydubai. On the day, if we share pertinent operational issues such as resource levels, facility constraints, GSE issues, and overall airport passenger numbers, we can make more educated decisions.”
“The trick is to get the software to predict bottlenecks and areas of concern that may affect the success of the operation,” he continues. “The airline, airport company and ground handler need to be linked up at their hub, with the next potential step looking at collaboration with ATMs. Again this would help to maximize the use of all resources and ultimately provide a better customer experience.”