Skyguide is overcoming one of the disadvantages of the ‘first come, first served’ principle where aircraft queuing at arrival route entry points just before the end of the night flying restrictions cause unnecessary noise and CO2 emissions.
As part of the iStream project at Zurich Airport, skyguide, together with other air navigation service providers, airlines, airports and regulators has undertaken early morning flight trials into Zurich. With the introduction of Target Time Management, a precise slot is assigned to each aircraft, with the aim of increasing the fluidity of air traffic and reducing noise as well as fuel consumption.
In the same vein, the extended arrival management, also known as XMAN, is optimising the arrival flow and cutting aircraft holding time at airports by adapting cruising speed while the aircraft flies through airspace managed by neighbouring control centres, often several hundred kilometres away from the airport, which reduces fuel burn and CO2 emissions. Less airborne congestion in terminal areas will also contribute to improving operational safety by reducing the workload of pilots and air traffic controllers and limiting noise.
“Our technical systems, airspace design and operational procedures are continuously improved to offer increased safety and capacity to airspace users. This in turn usually helps to shorten flight trajectories, thus saving fuel and lowering CO2 emissions.” said Thierry Brégou of Skyguide environmental affairs.
The improvement of procedures also makes it possible to improve flight trajectories in the vertical plan. International letters of agreement for the summer and winter seasons have been signed concerning the handover of responsibilities between the controllers of different centres. This will help to optimally adjust flight profiles according to the differences between low- and high-traffic periods, governed by the principle that the energy efficiency of an aircraft varies with its cruising altitude. Skyguide estimates that 7.8 GWh per year can be saved in keeping aircraft at their optimum flight level as long as possible.
Skyguide also plans to make major savings from the gradual introduction of more direct routes. Improvements are implemented every year within the framework of the Direct Routing Airspace project, enabling enables better planning of flights passing over Switzerland, with shorter flight routings. An even more ambitious project – Free Route Airspace – is intended to be implemented by 2022.
Eurocontrol meanwhile has recently reported on the ‘First Rotation Hours Optimisation Trial’, a partnership since summer 2017 with SWISS, Skyguide, Zurich Airport and the Central Office for Delay Analysis.
The trial aims to develop a procedure to minimise the number of misconnections at Zurich. Eurocontrol said that recurring air traffic flow management (ATFM) restrictions at Zurich and a lack of information on SWISS’ schedule meant the result is all too often very short connecting times for passengers.
Following 211 trial services by SWISS, Eurocontrol reported:
- 76% departed in accordance with their initially allocated calculated take off time (CTOT), arriving in Zurich on schedule;
- 24% departed outside their initially allocated CTOT window for operational or technical reasons (mostly slot revisions owing to late arrival, last minute loading or boarding;
- 99.12% of the transfer passengers from the selected trial flights were able to board their connecting flight on time thus helping reduce delays;
The services of other airlines were not affected negatively by the trial procedure, since the trade off between prioritised and non prioritised services was only done with suitable SWISS flights.
SWISS said it is convinced that user driven prioritisation processes are beneficial to all ATM stakeholders, and that they are an important prerequisite for enhancing operational control. The company now aims to develop the concept further and prioritise up to four daily services.