ATM Efficiencies a ‘Green’ Prerequisite

Perhaps the quickest means to help European aviation meet its plan for decarbonization rests with air traffic management and aircraft operations, which together account for one of four pillars of the industry’s response to achieving net-zero carbon emissions by 2050. Effective implementation of ATM efficiencies could result in a significant reduction in CO₂ and a major contribution toward the effort to meet interim targets within 15 years.

The European aviation sustainability Destination 2050 initiative identifies a route to achieving net-zero CO₂ emissions by 2050 through a combination of four key measures. Apart from ATM efficiencies, the three other “pillars” consist of improving aircraft and engine technologies, which could achieve emission reductions of 37 percent; using sustainable aviation fuels (SAFs), estimated to reduce emissions by 34 percent; and implementing economic measures that could result in reductions of 8 percent.

For the European ATM sector, the challenge involves making every journey as environmentally friendly as possible and achieving the “perfect green flight.” In a white paper published by Eurocontrol, a significant advance toward that end could actually happen through simply better use of existing measures, with all actors working together more effectively.

Even without factoring in major technological leaps such as hybrid/fully electric or hybrid/fully hydrogen-powered aircraft, the agency estimates that per flight, more effective use of existing tools could eliminate up to 4,286 kg of CO₂ emissions (25.8 percent) by 2030 compared with 2019, out of an average 16,632 kg of CO₂ for a total flight in the wider European area (ECAC – European Civil Aviation Conference, consisting of 44 states including all 41 Eurocontrol member states).

Better use of fuel-efficient air traffic management improvements could deliver 8.6 percent to 11.2 percent (up to 1,863 kg) of those reduced CO₂ emissions per flight. To realize the benefits, accelerating the transition from European research and development through the SESAR modernization program to deployment as well as improving the functioning and performance of the network to the greatest extent will require a network-centric cooperative decision-making (CDM) process that engages all network actors.

Such reductions will massively increase when emerging breakthrough developments (electric, hydrogen, or hybrid aircraft) enter into commercial service, although the two most short-term promising fuel/CO₂ savings accelerators derive from further use of the currently implemented continuous climb and descent operations (CCO/CDO), and free route airspace (FRA), where air navigation service providers (ANSP), airlines, airports, flight plan service providers, and the Eurocontrol Network Manager all play a key role.

Many measures have gotten underway as part of the European Commission Single European Sky (SES) initiative, with European ANSPs already implementing more than three-quarters of initial FRA—mandated by the end of 2022 under EU regulations. The FRA environment allows airspace users to plan more efficient flight paths between defined entry and exit points and, once fully implemented Europe-wide, potential savings could reach 3,000 tonnes of fuel per day and 10,000 fewer CO₂ tonnes per day. The resulting efficiencies could result in route-distance savings of up to 500,000 nautical miles and €3 million in fuel costs.

The takeoff phase offers a number of potential improvements, of which CCO generates the most important environmental benefit. Air traffic controllers should, as far as possible, clear flights to climb, avoid unnecessary level-offs, and permit more fuel-efficient CCOs. A 2018 Eurocontrol study showed that optimizing the CCO and CDO phases could deliver fuel savings of up to 350,000 tonnes per year for airlines, corresponding to more than 1 million tonnes of CO₂ and €150 million in fuel costs. Another Eurocontrol study carried out during the Covid-19 crisis showed that the average time in level during descent has fallen by 33 percent, suggesting that a 30 percent CDO target could be reasonable once traffic returns to normal.

Improved Network Flight Planning Delivers More Direct Flights

Over the past year, the Eurocontrol Network Manager Flight Efficiency Task Force identified more than 4,500 tailored rerouting proposals. The task force brings together the pan-European agency, airspace users, and ANSPs. Its proposals have helped save a typical airline more than 131,000 nm, around 800,000 kg of fuel, and more than €113,000 in route charges while reducing CO₂ emissions by at least 2,514 tonnes.

Eurocontrol NM’s automated group rerouting tool gives aircraft operators visibility on possible other options in the network. The tool displays proposals to the originator of the flight plan, taking into account their constraints through a set of pre-defined parameters set by each operator; it also considers wider variables such as the weather and the latest state of the network.

Applied during the pandemic, the improved network flight planning approach delivered more direct, ‘green’ flights due to a relaxation of 1,200 flight restrictions—the so-called Route Availability Document (RAD) measures—saving 26,000 nm per day. It also preceded Putin’s invasion of Ukraine, which has closed or restricted airspace, disrupted traffic flows, and canceled and re-routed flights, adding a huge additional layer of complexity to the network situation as the summer flight schedules take effect.

“Our focus is on the close collaboration with all aviation partners to optimize trajectories and minimize delays, costs, and aviation’s environment footprint,” said Iacopo Prissinotti, director of Network Management at Eurocontrol.

Latam Free Route Optimization Trials Show Big Benefits

Meanwhile, the early results from four end-to-end route optimization trials in Latin America and the Caribbean have demonstrated significant savings in time, fuel, and carbon emissions.

Carried out by the CANSO ATFM Data Exchange Network for the Americas (CADENA) as a Planned Airway System Alternative initiative, the trials took place for 90 days in the second half of 2021 and involved one aircraft from one airline on each of the selected routes. Over the course of the trials, each aircraft produced significant savings and showed how one could project those savings per aircraft over the course of a year.

Following their success, the use of the trial-completed routes has now been extended for one year. Airlines can continue to use the routes and benefit from operational savings until their publication in Aeronautical Information Circulars or Publications (AIC, AIP). The trials involved coordination with a range of stakeholders including airlines, ANSPs of the countries along each route, and regional aviation bodies.

“The savings and CO₂ reduction we’ve seen so far are remarkable and demonstrate the aviation community's commitment to a sustainable industry,” said Javier Vanegas, CANSO director of Latin America and Caribbean affairs. “The success of the trials has encouraged other airlines to submit more optimized proposals for testing and the CIIFRA project team is now working with states and ANSPs to publish the tested optimized routes within their AIPs. We are encouraged by these developments, and sharing knowledge and developing best practices always makes our industry stronger.”