The concept of green flights consists of three aspects – green departure, direct route and green approach. Separately and together, they contribute to greener flights – which benefit both airlines and passengers.
Green approaches have been developed at Stockholm Arlanda Airport in a collaboration between Swedavia, international air navigation organisations and SAS. Today they are performed at all Swedavia airports. So far, at Stockholm Arlanda it has only been possible to perform green approaches in light traffic since green and standard approaches cannot be combined in heavy traffic.
Green approach – how it works
In a green approach, there is slightly less noise as well as a reduction in fuel consumption and atmospheric emissions. A green approach means that an aircraft descends continuously from its cruising altitude to the runway. By descending continuously, the aircraft requires almost no engine thrust, thereby saving fuel and reducing emissions.
Since the computer on board an aircraft is in continuous contact with ground equipment, the entire flight can be adjusted to an exact predetermined landing time. This also means the air traffic controller and the pilot can together plan an even approach − the plane “coasts” downward instead of descending in stages, which is the standard procedure. Such an approach can save an average of 150 kg of fuel and 450 kg of carbon dioxide emissions.
Green Connection – shorter flight paths
Swedavia took part in the project Green Connection, which was completed in 2012. In the project, which was aimed at optimising and shortening all flight paths, trials were conducted in which the flight path between Stockholm Arlanda and Göteborg Landvetter was shortened using modern satellite-based technology. The flights involved in the project generated a savings of at least 130 kg of carbon dioxide per flight. The shorter flight path remains in place and is still used today.
Green departures entail a reduced environmental impact during the departure stage by optimising ground movements and the operating of engines on the ground and by using the most efficient departure possible en route to cruising altitude. By planning take-off when the aircraft is still at the gate, the engines only need to be started when it is known that the aircraft will not need to queue en route to the take-off runway. When the aircraft takes off, engine thrust is optimised all the way to cruising altitude, which means fuel is saved.