Airport Operations

Airport Collaborative Decision Making (A-CDM)

Sharing Information & Collaborating to Optimize Airport Operations

Airport Operators implement the Airport Collaborative Decision Making (A-CDM) process to improve overall performance of operations at the airport. Overall performance can be improved through increasing communication and collaboration between all major stakeholders responsible for managing a flight into and out of an airport, to include the aircraft turnaround processes.


  • Removes lack of common situational awareness between airport stakeholders
  • Prevents non-transparent aircraft turnaround processes
  • Averts non-optimized departure sequences resulting in taxiway queues & delays
  • Avoids non-adherence to Air Traffic Flow Management (ATFM) slots

Airport-Collaborative Decision Making (A-CDM)

Airport Collaborative Decision Making (A-CDM) is a set of principles, operational procedures, automated processes, and integrated technologies that allow all key stakeholders at an airport to share data with each other in order to collaborate more transparently and efficiently.


The main objective of implementing A-CDM is to improve the overall efficiency of operations at the airport. A particular focus is on improving the predictability of the aircraft turn-around process and pre-departure sequencing processes, and sequencing aircraft to the runways minimizing taxi times and delays. Additionally the objective is to improve traffic flow management across a network of airports. In Europe, for example, the latter is achieved when A-CDM airports share their departure planning information (DPI) messages with the Network Manager and do receive Flight Update Messages (FMU) about progress of an arrival flight.


Airport CDM Key Stakeholders and the Benefits

The enhanced, timely exchange of information at the center of the A-CDM process creates an accruing set of operational gains for local airport partners, for the network as a whole, and most importantly for the passenger experience.


Core Elements of A-CDM


Information Sharing –¬†Information Sharing is the first and most important component of A-CDM because it creates the data and information foundation for common situational awareness.


Milestone Approach – Implementation of the target off-block time (TOBT) by using the Milestone Approach to improve predictability during the turnaround process of aircraft. TOBT and the Milestone Approach are two essential elements required for the implementation of the remaining A-CDM elements.


Variable Taxi Times (VTT) – With VTTs in place, the link between off-block time and take-off time becomes transparent to all A-CDM stakeholders.


Pre-Departure Sequencing – With the Pre-Departure Sequencing function the Target Startup Approval Times (TSATs) can be calculated, providing an optimized off-block sequence of aircraft.


Collaborative Management of Flight Updates (Link to the Network Management) – Sharing FUM and DPI messages with network management improves traffic flow management across a network of airports.


CDM Under Adverse Conditions – When the components of A-CDM described above are in place, the last step is to implement CDM in adverse conditions, which includes implementing additional procedures that are adhered to during an emergency or when there are major disruptions from weather (e.g., de-icing).


Airline Operators

  • Shorter taxi times, shorter holding times before runway access, no waiting in front of occupied gates
  • Reduced engine run time on the ground resulting in lower fuel consumption (fuel savings) and less noise
  • Reduced emissions of carbon dioxide, nitrous oxides, and particulates
  • Reduced delays
  • Increased capacity with same fleet
  • Improved passenger experience and satisfaction


Airport Operators

  • Improved punctuality (on time performance)
  • Improved gate & stand planning and management
  • Reduced environmental impact (noise & emissions)
  • Reduced apron and taxiway congestions
  • Higher service quality with knock-on benefits to company image and customer satisfaction


Ground Handling Service Providers

  • Improved predictability of aircraft turnaround operations
  • Better planning and use of resources leading to lower operational costs
  • Maximize adherence to service level agreements with airlines and airport
  • Improved customer satisfaction


Air Navigation Service Providers

  • Optimized use of airport airside resources
  • Reduced ground congestions
  • More predictable traffic between gates and runway leading to controller work load reduction
  • Higher service quality


Network Manager

  • Optimized use of airspace and airport capacity
  • Improved ATFM slot adherence
  • Fewer wasted slots

ORTHOGON Pre-Departure Sequencer (PDS)

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ORTHOGON Departure Manager (DMAN)

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"Throughout Gatwick's A-CDM 55 program, Harris Orthogon has provided a high quality product and service delivery."

Chris Howell, Head of Business Systems - Gatwick Airport IT

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