Off the Beaten Track: How Aer Lingus and NATS are cutting fuel burn and CO₂ over the North Atlantic

What happens when airlines challenge long-established operating habits and combine them with data-driven insight and close collaboration? In the case of Aer Lingus and NATS, the answer is clear: meaningful fuel savings, reduced CO₂ emissions and a compelling case for rethinking how we operate across the North Atlantic.

Last year, Aer Lingus and NATS partnered on a two-week trial to explore the operational and environmental benefits of flying ‘random’, user preferred routes North or South of the traditional Organised Track Structure (OTS).

The objective was simple but ambitious: to measure what fuel and CO₂ savings could be achieved when aircraft operate on routes outside of the OTS.

Historically, some airlines have tended to file on the OTS not because of any air traffic control requirement, but because the track system offers predictability, perceived ease of clearance and confidence in achieving planned entry points and flight levels. Over time, this has led to an operational preference for the OTS during peak traffic times, even though random ie non-OTS – routing has always been available and, in many cases, offers more direct and efficient flight profiles.

During the trial, the majority of Aer Lingus A321 flights between Ireland and North America filed random routes whenever fuel or time savings were expected. The NATS Analytics team closely monitored performance throughout, sharing daily insights on aircraft performance and operational outcomes to support informed decision-making.

Image courtesy of Aer Lingus

While there was a modest reduction in flights getting their planned oceanic entry point and level when operating random routes compared to the OTS, the impact was significantly less than anticipated by both flight crews and flight planners.

Such was the success of the trial that random routing has been deployed across all Aer Lingus fleets as a standard operating procedure where operational efficiencies and savings exist.

Chris Jones, Technical Pilot at Aer Lingus, said: “This ambitious trial was designed in close consultation with NATS. Both Aer Lingus and NATS, whilst optimistic, were unsure of the operational effect the trial would have. Thanks to daily analytics and updates throughout the trial, we were able to manage any risk to the operation effectively and see the immediate benefits the trial brought.

“After the two-week period, we reviewed the data in conjunction with NATS, adjusted our internal procedures to balance risk and fuel/time savings and several months later overhauled our SOPs for crews and flight planning. The results of this trial have delivered notable fuel savings. We hope to continue to review the data with NATS regularly, along with assisting them in future innovations.”

From a NATS perspective the value was clear, reflecting a combination of effective operational implementation, data-driven insights and strong collaboration with our customers. The analytical evidence demonstrated results above expectations and we’re looking forward to engaging with additional airline partners to build on this success with similar trials and further enhance operational performance across the North Atlantic.

Most importantly, this work directly supports the NATS strategy to move towards a carbon-negative future, showing how smarter routing and better use of data can deliver real progress on sustainability – without compromising operational performance.

Sometimes, the most effective route forward really is off the beaten track.