New standard arrival routes reduce flight emissions

ANS Finland wants to provide the most environmentally friendly airspace in the world, and the new standard arrival routes at Helsinki Airport are a step in this direction.

Helsinki Airport has three physical runways, each of which are used in both directions and each of which has from six to eight standard arrival routes. Jari Lanteri, ATS Deputy Chief and air traffic controller at the Air Traffic Control Centre (ATCC) Finland, explains that the standard arrival routes are designed to control approaching air traffic so that the traffic flow remains smooth and predictable. The flight routes are subject to noise regulations. In daytime, from 6 a.m. to 9 p.m., it is possible to use shorter routes than during the night.

Significant impact on annual level

Introduced in April, the new standard arrival routes shorten the travel distance of approaching aircraft by more than 11 kilometres depending on the direction of the approach. Is it a lot or a little?

Considering that there are about 300 landings on Helsinki Airport each weekday, the new practice means saving over 3,000 kilometres in flight distance per day.

When we look at the impact on an annual level, the scale becomes large. Last year, 94,000 flights landed at Helsinki Airport. At that volume of traffic, the six miles of an individual flight translates into one million kilometres. Over a period of one year, flights are thus shortened by a distance that equals 25 trips around the world.

This means significant fuels savings and, at the same time, a considerable reduction in CO2 emissions.

Increased predictability

Apart from shortening the journey, the change has also brought about other significant benefits.

“With this new practice, airlines and air traffic control can better predict the flight profile of a descending airplane, in other words, the plane’s altitude along the flight route,” explains Jari Lanteri.

Previously, if the approach air traffic controller at Helsinki Airport wished to shorten the route in order to speed up the traffic flow, she/he had to do a lot of manual work and instruct the pilot by ordering them to follow radar headings.

Now, it is often enough for the air traffic control to provide a single clearance to the aircraft to determine the flight path until the runway threshold. Once the report arrives, the on-board computer of an aircraft calculates the inbound tracks, based on which the aircraft makes the approach using its own navigation.

The new practice also improves safety because an aircraft approaching the airport will always need explicit permission to turn towards the final of the runway and other approaching traffic, and the that situation no longer needs to be prevented by the air traffic controller by means of radar headings issued for the aircraft.

Approach at optimal altitude

With the new method, the on-board computer can calculate the optimal altitude more accurately. This is a significant improvement. Previously, aircraft typically approached the airport at an unnecessarily high altitude due to old standard approach routes concept being usually too long.

“Then, as the aircraft lowered its altitude when the route was shortened due to the traffic flow, it had to control its speed and the energy the aircraft carries through aerodynamic braking or by manipulating the flight profile. In practice, this meant wasted energy and increased noise,” Lanteri points out.

Improved predictability maximises the use of the continuous descent approach, which saves fuel and noise. The method can reduce fuel consumption so that the emissions in the approach stage decrease by 10–30% with the noise level reduced as well.

Up to now, about 70% of descents at Helsinki Airport have been carried out using the continuous descent approach, which is a top-notch figure among airports around the world.

A win-win-win situation

The standard arrival route reform has required about 18 months of preparatory work at ANS Finland. Jari Lanteri explains that they have utilised the lessons and experiences obtained from the Paris Charles de Gaulle, Barcelona and Prague airports, among others.

“We explored the concepts used at these airports and came to the conclusion that we can achieve even a better solution,” Lanteri says proudly.

ANS Finland has collaborated closely with Finavia and air carriers to introduce the new standard arrival routes. The reform has also required training of all air traffic controllers working at Helsinki Airport.

“Airlines’ views on the reform have been encouraging. In the future, we will conduct a customer satisfaction survey to investigate whether the reform has achieved the targets set for fuel economy and more predictable flight profiles.”

The reform benefits both airlines and the environment.

“That is true, but air traffic control benefits as well, thanks to simpler working methods. The reform helps air traffic controllers form a clearer picture of traffic flows by providing better tools. The air traffic controller no longer needs to concentrate so much on manual route guidance, which also reduces radio traffic,” Lanteri points out.