With the launch of A-CDM or Airport Collaboration Decision Making initiative, airport partners such as airlines, groundhandlers and air traffic control share information on airport and flight operations to enhance operational efficiency.

The airport environment is fast-paced and complex, involving different agencies working together to achieve smooth and efficient operations. On the tarmac, a flurry of activities takes place – re-fuelling, loading and unloading of baggage, aircraft servicing and aircraft interior cleaning – once an aircraft lands and docks. Within the terminals, passengers check-in for their flights, go through security screening and get ready to board the aircraft. These activities happen 24 hours a day at Changi Airport.

However, most passengers may not be aware of the coordination work between the numerous airport agencies that is needed to achieve efficiency. In a dynamic airport environment, a flight may arrive or depart earlier or later than its scheduled time, which will affect the chain of operations that takes place after. With growing traffic, there is a stronger need to optimise the airport’s infrastructure and operational efficiency – through A-CDM. 

How does A-CDM-work?

The A-CDM concept involves two key components – Target Off-Block Time (TOBT) and Target Start-up Approval Time (TSAT). TOBT refers to the predicted time that all the groundhandling activities will be completed, while TSAT refers to the time an aircraft can expect to push back.

The airline or its ground handling representative is responsible to provide the TOBT for its departing flights while Air Traffic Control (ATC) provides the TSAT. These operational information is shared amongst airport partners through the Airport Operations Centre System (AOCS) which is a custom-designed software to facilitate the collaboration across all key airport partners. This process, which promotes the philosophy of ‘best planned, best served’, reaps benefits for many parties, including efficient use of infrastructure and resources, fuel savings for the airlines, reduced carbon footprint and enhanced experience for the travellers.

Benefits of A-CDM

One of the key benefits of the programme is the efficient utilisation of infrastructure and resources.  For instance, if the departure time of a flight from the origin destination is delayed, the airline can share this information with the destination airport and the rest of the airport community can initiate plans to mitigate this impact before its arrival. Resources already lined up for that flight, such as the baggage and aircraft interior cleaning teams, can be deployed to another flight which is arriving earlier than the former.

The sharing of information also benefits the departure process. With prediction of push-back readiness given by airlines and groundhandlers, ATC is able to optimise the departure sequence and reduce take-off waiting time of flights at the runway holding point. Before A-CDM was implemented, airlines took off based on first-come-first-serve principle. ATC could only process each departure flight sequentially based on the sequence at which the pilot calls for its clearance. With A-CDM, ATC is able to sequence the departure queue in advance based on expected readiness of flights. This sequencing helps to reduce the waiting time between subsequent departures, taxiing time and therefore the runway is used more efficiently. The reduced waiting time at the runway helps airlines save fuel costs and reduce their carbon footprint. . The overall passenger experience is also enhanced as the departure process they go through is smooth and their flights depart on time.

Mr Yeo Kia Thye, Managing Director for Airport Operations Planning & Airside, who heads the A-CDM team, said, “We are very happy to have implemented A-CDM successfully at Changi Airport. Since the implementation of A-CDM, taxiing time for aircraft is reduced and our runways are used more efficiently. This is only possible with the support of our key stakeholders.  The journey has been a fruitful one, and the investment in A-CDM programme has yielded significant benefits to the airport community and passengers. Together, we hope to achieve greater efficiency and productivity as ONE Changi.”