The North Atlantic Ocean is one of the busiest airspaces in the entire world. On average, about 1,800 flights cross the eerie ocean every day. The ocean connects two major markets, Europe and North America. Flights range from commercial to cargo to military personnel. Considering that there is minimal radar coverage above the ocean, how do airplanes continue on course without a hiccup? Even if the pilot has filed in a correct flight route, tower communication is still necessary. The answer is, The North Atlantic Organized Track System (NAT-OTS) is known in shorthand as the North Atlantic Tracks, or even as NATs.
The terminology refers to a set of pre-determined routes over the North Atlantic Ocean that must be followed by aircraft flying between Europe and North America on any particular day. The average altitude of aircraft operating over these routes is between 29,000 and 41,000 feet. To ensure separation between aircraft, dedicated oceanic control centers monitor entry and movement along these tracks. The main objective of these routes is to allow air traffic controllers to efficiently separate the aircraft. Allowing aircraft to set their coordinates would make ATC’s job much more difficult due to the volume of NAT traffic. They’re positioned to reduce the impact of headwinds while maximizing the influence of tailwinds on the aircraft. This increases efficiency by lowering fuel consumption and flying duration. The routes are created twice daily to account for the varying winds above and the main traffic flow to achieve such efficiency. The ‘Jetstream,’ which causes eastbound aircraft to encounter tailwinds, is the most significant of them. This is why a transatlantic airline service’s Europe-bound rotation has a considerably shorter planned flight duration. Storm Ciara, for example, helped a British Airways Boeing 747 travel from New York to London in only four hours and 56 minutes last February. It arrived 80 minutes ahead of schedule, setting a new record! As a result, the NATs are built to maximize the benefits of the tailwind while minimizing the consequences of headwinds for westbound aircraft. As a consequence, a set of pathways has been created that is optimized to save flying time.
Concorde did not fly on the North Atlantic Tracks because it flew at a significantly higher altitude than subsonic airliners, between 45,000 and 60,000 feet (14,000 and 18,000 meters). At these heights, weather differences were so small that Concorde flew the same route every day. These fixed tracks were designated as ‘Track Sierra Mike’ (SM) for westbound flights and ‘Track Sierra November’ (SN) for eastbound flights, with a third track known as ‘Track Sierra Oscar’ (SO) utilized if needed.
It will be exciting to watch what the future of the North Atlantic Tracks holds as coverage in the North Atlantic expands in the coming years. For the time being, they will keep airplanes safely separated along with this busy and lucrative sector, assuring the shortest possible journeys ‘over the border.’