Towards Green ATM

SESAR realises already today environmental benefits through live trials or changes in real operations. See here below some examples of green procedures per domain of flight:

On the ground

The key achievement for ground is to minimise aircraft holdings and distance rolling on the ground. For example, in a number of airports Collaborative Decision Making (CDM) is already in place for organising departure sequences. The general idea is to have a target start time for each and every departure. This improves the predictability and allows a reduction of taxi-out and taxi-in times. Having the predictability and information single engine taxing out is allowed by absorbing any potential delays at the parking stand, minimum usage of the aircraft APU etc.

More examples of ground initiatives to reduce fuel:

  • CDM for departures and arrivals;
  • Implementation of DMAN (Departure management) and AMAN (Arrival Management) tools;
  • Pre-Departure Sequences;
  • Better weather information;

Green ground procedures are covered in SESAR work packages 6, 9, 11, 13, 14 and 15.

Realised projects:

 

Green Take-Offs - Green Departures

There is a large variety of how to perform the environmentally most advantageous take-off. Today, much consideration is given to noise constraints. However, a noise abatement departure procedure that is logical for one aircraft can be completely erroneous for another aircraft. Both in terms of noise and emissions. This indicates the importance of data availability and flexibility in the system.

Aircraft taking off are per definition in the segment of the flight where they are at their heaviest, meaning that they burn most fuel/time. In the early years of aviation, aircraft could climb away from airports in a simple continuous climb to make the most efficient use of fuel. However, with increasing air traffic there is a need to compromise with aircraft being assigned to certain routes and flight levels to keep them separated from each other. These compromises mean that aircraft often climb in a series of steps separated by periods of level flight, neither efficient nor environmentally friendly.

Examples of departures initiatives to reduce fuel:

  • Continuous climb;
  • Implementation of PBN procedures allowing unrestricted climbs;
  • Better weather information.

Green departure procedures are covered in SESAR work packages 5, 7, 8, 9, 11, 13, 15.

Realised Projects:

Green Cruise

Aircraft cruise differently, depending on factors such as airframe design, weight, range, weather conditions and the airspace they are flying in. Flight management systems onboard aircraft can determine the most efficient cruise altitude and speed to optimise fuel burn. ATM can assist in this process by enabling capacity in the en-route phase of flight to offer aircraft the cruise levels and speeds they request. Further efficiency gains also include route changes to take advantage of favourable wind conditions for example.

Examples of cruise/oceanic initiatives to reduce fuel:

  • Direct routing;
  • Better lateral and vertical profiles
  • Choosing the right Cost Index

Green cruise procedures are covered in SESAR work packages 7, 8, 9, 10, 11, 13, 15.

Realised projects:

 

Green Approaches

A successful Green Approach starts already at the Top of Descent. The target is to use all potential energy of the aircraft and convert it to kinetic energy which keeps the aircraft flying during the descent. The descent planning is therefore the critical part where all the potential energy must be balanced versus the needed kinetic energy during the descent. If the descent is started to early aircraft engines must be used to energy during the descent. If the descent is started to late valuable energy is burnt (from fuel) and must later be eliminated by the use of drag increasing device. The opportunities for fuel burn and emissions reduction in the descent phase through the reduction of ATM interference in planning of the descent is therefore crucial. It includes using sophisticated arrival management tools to better sequence aircraft ensuring shortest possible track distance, correct track distance information and minimal holdings. The aim is to allow all aircraft to descend uninterrupted from top of descent without using additional thrust, which burns fuel.

Examples of green approach initiatives to reduce fuel:

  • Continuous descent operations;
  • Idle reverse at landing;
  • Implementation of PBN procedures allowing unrestricted climbs .

Green approach procedures are covered in SESAR work packages 7, 8, 9, 10, 11, 13, 15.

Realised projects: