Sustainability through tried and trusted methods

Air navigation service providers (ANSPs) have a big role to play in helping aviation reach its ambitious net-zero carbon emissions target by 2050.

Often, new technologies are touted as the primary source of hope. New systems offer a variety of opportunities from improving flight trajectories to reducing power consumption. Across the stakeholder chain, there is talk of hydrogen-powered aircraft, electric ground vehicles and smart airports.

But few aviation companies have money to spare at the moment. The global pandemic has brought the industry to its knees financially, making new technologies a distant prospect for many.

This doesn’t mean that ANSPs cannot have a major influence on the climate challenge, however.

“An era of cost constraints is not an excuse,” says Michelle Bishop, CANSO Director of Programmes. “ANSPs can still make a difference. In fact, there are tried and trusted methods to reduce carbon emissions that don’t cost anything.”

Airspace redesign

Perhaps the most obvious example is better use of airspace. Every ANSP already has the technology to improve airspace use but is constrained by a mixture of rules and mindset.

Cooperation with the military springs instantly to mind. India adopted a flexible use of airspace (FUA) strategy after negotiations between civil and military users. Some 40% of Indian airspace is reserved for military operations and such major hubs as Delhi also house military bases.

Following talks, the Airports Authority of India can now direct flights through portions of restricted airspace across India, saving up to 15 minutes and so cutting fuel use and carbon emissions.

Similar negotiations in the past have opened up time and fuel-saving routes in China, the Middle East and many other areas.

Indeed, optimising airspace is saving CO₂ emissions throughout the world. In the UK, NATS has completed what it terms “the biggest ever geographical airspace change” in the country. The Free Route Airspace (FRA) concept allows airlines to take the optimal route, considering such variables as weather and wind speed. It is estimated the initiative will save some 500,000 nautical miles of flying every year, equating to an annual reduction of 12,000 tonnes of CO₂.

Organised Track Structure

NATS is also involved with NAV CANADA in improving the heavily congested North Atlantic traffic corridor.

A University of Reading study that looked at the potential benefits if flights took better advantage of the prevailing winds across the North Atlantic concluded that close to 200 kilometres worth of fuel could be saved per flight.

“Upgrading to more efficient aircraft or switching to biofuels or batteries could lower emissions significantly but will be costly and may take decades to achieve,” said Professor Paul Williams, an atmospheric scientist at the University of Reading and co-author of the new study.

“Simple tweaks to flight paths are far cheaper and can offer benefits immediately. This is important, because lower emissions from aviation are urgently needed to reduce the future impacts of climate change.”

NATS and NAV CANADA are now experimenting with trials to remove the Organised Track Structure (OTS) to judge the results. The travel restrictions imposed as a result of the coronavirus pandemic have been, for once, something of an advantage. Around the turn of the year, there were about 500 flights a day instead of the usual 1,300 flights.

The OTS puts aircraft in single file 14 miles apart, with the highways 30 miles apart. Eastbound and westbound flights also fly at different levels. From a safety perspective, the concept can’t be questioned as there hasn’t been a collision in the area despite it being out of radar surveillance for much of aviation’s history.

Now that surveillance has vastly improved, the plan is to drop the OTS on days with favourable weather conditions.

Coming and going

Lots of work is also being done closer to the airport. In 2021, the Federal Aviation Administration (FAA) introduced 42 optimised descent profiles (ODPs) across the United States. It reports that these will save around two million gallons of fuel per airport, saving some 18,000 tonnes of CO₂ emissions each.

Spanish ANSP, ENAIRE, allowed 81% of all flights to employ continuous climb in 2021, part of its 2025 Flight Plan. The climb is the most fuel-consuming phase of flight, but relatively small improvements can yield enormous environmental benefits.

“ATM cannot decarbonise aviation, but we can make an important contribution to reducing excess emissions,” concludes Bishop. “It is important that we take that action in the near term. We have to remember that 2050 is the deadline and not the time to start. Fortunately, there is a lot ANSPs can do without waiting for technology advancements, such as the better use of airspace. It doesn’t need huge investment.

“By 2030, we should start to see an acceleration of the energy transition with new fuels, electrification and eventually power sources, such as hydrogen. Efficiency improvements we make now will not only reduce cumulative emissions but also will ensure the impact of these new fuels are maximised.”