Figure this. Only one aircraft can arrive/depart from a particular runway at a time, and aircraft need to be separated to avoid collisions. Hence, this leads to a capacity constraint at airports. Not just that, you can only have so many aircraft on the ground in one go as well, which is related to the number of boarding gates and other aircraft bay in use.
When an air traffic control unit reaches full capacity, they put aircraft in a holding pattern, which is when they circle around, until its their turn to land. However, this is an ecologically and financially wrong way of doing things, and hence, over a period of time, the preference has moved to keep the aircraft on the ground at their place of departure, till it is time for them to fly, in line with their time of arrival at the other airport. This move also saves fuel for airlines.
Air traffic flow management (ATFM) is this regulation of air traffic, to make sure that a particular airport does not exceed its airport or air traffic control capacity in handling traffic. The ATFM also ensures that available capacity is used efficiently.
Introducing the Centralised Air Traffic Flow Management System
Earlier, each and every Air Traffic Control made independent decisions about how to restrict and manage flights. This often resulted in less than optimal utilisation of available airspace, airports, and aircraft resources. This changed, when the Airport Authority of India (AAI) started implementing a Centralised Air Traffic Flow Management System (C-ATFM) in phases.
The C-ATFM system is primarily meant to address the balancing of capacity against the demand to achieve optimum utilisation of the major resources such as airport, airspace and aircraft at every Indian airport where there is a capacity constraint. The C-ATFM ensures enhanced safety in addition to cost savings to airlines resulting out of fuel savings approximately to the tune of INR 1,680 Crores per year.
The first phase went live on April 27, 2017, and saw the integration of the six major airports which handles almost 60% of India’s air traffic: Delhi, Mumbai, Kolkata, Bengaluru, Chennai and Hyderabad. The Central Command Centre (CCC), located in Delhi was inaugurated on January 26, 2017. On June 22, 2019, the new C-ATFM centre was inaugurated.
Under the second phase, the C-ATFM now covers 36 flow management positions (FMP) or traffic management units (TMUs) including 6 defence airports in India which report to the CCC in Delhi. The CCC receives strategic and tactical weather, airspace, traffic, airport information for accurate situational awareness and decides on needed ATFM measures. All the other airports in India are also connected via the internet to the C-ATFM
It manages and optimises traffic flows by actively collaborating with airlines, airport, defence and other stakeholders on a daily basis. The CCC advises the FMPs and they, in turn, implement the ATFM program at local area control centres, air traffic towers and so-on.
The C-ATFM helps in relieving the pressure and helping individual ATCs in case of delays and over capacity. This could be a pre-flight measure, which include rerouting, minutes in the trail (minimum safe distance between aircraft expressed as a time interval in minutes), a ground delay program or an airport stop program.
The second is in-flight measures for aircraft already in the air such as rerouting, miles in trails (minimum safe distance between aircraft expressed in miles, often used to manage arrival flow at an airport), fix balancing, airborne holding and level capping. The ATFM excludes flights experiencing emergency including unlawful interference, flights on search and rescue, medical evacuation flights, flights with Head of State status and other flights identified by the State.
India is seventh in the world after the US, Europe, Australia, South Africa, Japan and Brazil to successfully implement the C-ATFM. The C-ATFM is now being integrated with the Global ATFM programme.
So, the next time you are in the air, don’t fret if you are spending a little longer time on the ground before you take off. Your aircraft is now under the control of the C-ATFM.