Brussels Airport and skeyes begin demonstration flights with steeper and innovative approach trajectories

Brussels Airport and air navigation service provider (ANSP) skeyes will commence demonstration flights as part of the HERON project from 1st October. The aim of these flights is to assess whether landings with a steeper approach than usual could offer benefits in terms of reducing noise impact for surrounding communities, as well as lowering CO2 emissions and fuel consumption.

skeyes and Brussels Airport have been participating in the "Highly Efficient Green Operations (HERON)" project since last year. They are contributing to the project by conducting operational flight demonstrations of green landings, which will begin on 1st October.

The purpose of the demonstrations is to assess the environmental impact of the 'Increased Second Glide Slope' solution, which specifically aims to reduce noise disturbance during the aircraft approach phase. By initiating landings at a steeper angle, aircraft will remain at a higher altitude for a longer time and will also fly at lower speeds, resulting in reduced noise impact for surrounding residents.

During the test period, aircraft will use new procedures with steeper descent angles of 3.2 and 3.5 degrees, instead of the usual 3.0 degrees, on the most frequently used runways, 25R and 25L. These adjustments required the development of specific RNP (Required Navigation Performance) flight procedures for these demonstrations. An important milestone in the implementation of these new procedures was achieved a few months ago with a successful validation and calibration flight. In the meantime, the necessary publications have been released and approved by the relevant aviation authorities.


Increased Second Glide Slope - Aircraft will remain at a higher altitude for a longer time and will also fly at lower speeds, resulting in reduced noise impact for surrounding residents

Demonstration flights in two phases

The first phase will run from October to December 2024, focusing on a descent angle of 3.2 degrees. During the second phase, from February to April 2025, flights with a 3.2 degrees angle will be conducted on runway 25R, while the descent angle on runway 25L will be increased to 3.5 degrees. The demonstration will take place in two phases, with airlines such as DHL, Brussels Airlines, TUI, and Vueling participating in the tests, while other airlines will continue to use the standard descent angle of 3.0 degrees.

The 'Increased Second Glide Slope' (ISGS) solution is developed in partnership with Eurocontrol and Airbus and is part of the SESAR program, an ambitious European initiative aimed at modernizing air traffic management. This project is supported by CINEA - the European Climate, Infrastructure and Environment Executive Agency - and is one of the flagship projects within SESAR 3 Joint Undertaking's Digital Sky Demonstrators.

With these demonstration flights, skeyes and Brussels Airport are taking a major step towards cleaner, quieter, and more efficient aviation.

These demonstrations are part of HERON (Highly Efficient Green Operations), a large international consortium. HERON is led by Airbus and aims to carry out a series of ambitious developments and demonstrations to reduce noise, flight delays, fuel consumption, and CO2 emissions in air transport by proposing reduction measures, including more efficient flight operations. HERON involves 26 partners from 11 countries and will be supported by 6 airlines, 8 air navigation service providers, and 5 airports across Europe.