- European CDM -

1. Collaborative Decision Making Visit the European CDM website at www.euro-cdm.org for more information - European CDM - Collaborative Departures Sequencing ‘Optimising departure sequence according to the priorities of Airline and Airport as well as Tower ATC’ click for next step Made possible through shared, accurate estimates of Off-Block Time. click for next step The following pages illustrate Collaborative Departures Sequencing,highlighting how the collaboration would benefit all participants …. click for next page

2. Introduction At present departures at any airport are ordered according to the time at which they call for push-back - first come, first served. That, with taxi time, determines the departure sequence. (Although ATC may shuffle the sequence a little to increase runway throughput). click for next step There is no prior notification of the time at which flights expect to be ready for push back(in most cases). As a result, only very limited prioritisation of departures is possible. click for next step This demonstration illustrates what might be achieved by applying the CDM principles of . Flights that are time critical can be given priority. Consider the following scenario ..... click for next page

3. 5 minutes to push back and clear cul-de-sac. 10 minutes taxi time. XXX001 YYY002 If one a/c is manoeuvring, cul-de-sac is blocked for others. Flights XXX001 and YYY002 are in the cul-de-sac (other flights are elsewhere on the airport, with different taxi times). An airport apron cul-de-sac : click for next step ... click for next step ... click for next step ... click for next page ...

4. Ground Operations Co-ordinator for other Airlines Ground Operations Co-ordinator for Airline X Ground Operations Co-ordinator for Airline Y 17:00:00 17:01:30 17:01:00 17:02:30 XXX001 expected ready time 17:09 YYY002 expected ready time 17:10 ABC123 expected ready time 17:12 IJK001 expected ready time 17:13 ATC Tower Under CDM Ground Ops Co-ordinators try to advise ATC 10 minutes in advance of when a flight will be ready for start up/push back: click for next step ... click for next step ... click for next page ...

5. Departure Sequence Ready Estimate OBT Estimate TOT Estimate Flight CTOT ABC123 17:12 17:12 17:22 **** **** **** +5+10 XXX001 17:09 17:20 17:25 17:35 IJK001 17:13 **** **** **** YYY002 17:10 17:10 17:15 17:25 +5+10 ATC Tower ****** ***** **** **** **** Tower plans departure sequence : first come, first served (with some optimisation of sequence of wake vortex categories). 17:09 17:24 +5 17:15 17:27 17:14 17:29 ***** ***** click for next step ... XXX001 is ready before YYY002, so ATC plans XXX001 will depart first. click for next step ... YYY002 then has to wait until XXX001 has cleared the cul-de-sac - which takes 5 minutes - so YYY002 Off-Block estimate is 17:14. click for next step ... YYY002 now has 5 minutes to push back plus10 minutes taxi time - so YYY002 has a take-off time estimate of 17:29. click for next step ... This now means that YYY002 will miss its CFMU slot (CTOT) - TOT estimate for YYY002 is 4 minutes after CFMU latest Take Off Time. click for next page ...

6. Revised Departure Sequence Ready Estimate OBT Estimate TOT Estimate Flight CTOT ABC123 17:12 17:12 17:22 **** **** **** 17:09 17:24 XXX001 17:09 17:20 17:25 17:35 IJK001 17:13 **** **** **** 17:15 17:27 17:14 YYY002 17:10 17:10 17:15 17:25 17:29 ATC Tower ****** ***** **** **** **** ***** ***** • Airport Stand/Gate Manager (who would have to re-plan stand allocations if YYY002 given a later slot) ATC has prior estimates of ready time. Under CDM Tower is able to re-plan the departure sequence to avoid missing the slot: YYY002 17:10 17:10 17:25 17:10 17:15 17:25 XXX001 17:09 17:15 17:30 17:20 17:25 17:35 click for next step ... This improves efficiency for the :- • Airline • Passengers • ATC (who would have to request slot extension) click for next page ...

7. In the example we have just seen, a flight was given priority to allow it to meet its CFMU slot. There are other reasons why one flight may be given priority. For example: click for next step ... Stand and Gate Management If an incoming flight is waiting to use the stand or gate still occupied by a departing flight, that departing flight could be given priority over others. Apron congestion is reduced, and delays avoided. click for next step ... Destination airport curfew A departing flight has already been delayed (perhaps for technical reasons) and now runs the risk of arriving at its destination airport too late - after the curfew or after the airport has closed. Giving priority to that flight could save valuable minutes, avoiding the need to divert or cancel. click for next step ... Departure runway capacity ATC already tries to sequence departures according to their wake vortex category to optimise runway throughput. Advance notification of ready time may allow further optimisation, effectively increasing the runway capacity. click for next page ...

8. Collaborative Decision Making Visit the European CDM website at www.euro-cdm.org for more information Conclusion Collaborative Departures Sequencing allows flights that are time-critical, for whatever reason, to be givenpriority. Prioritising those critical flights means that some non-critical flights will be delayed a little. click for next step ... But the operational benefit from prioritising a single, critical flight outweighs the disadvantage of a slight delay to a non-critical flight. All airlines sometimes have flights that are time-critical, so all participating airlines benefit from the more flexible operations. • Collaborative Departures Sequencing also enables: • more efficient managementof stands and gates • increased runway throughput. click to end the show ...