North Atlantic Tracks (NATs) are daily high altitude transatlantic routes between western Europe and the eastern coast of North-America, which provide consistent separation between aircraft. Westward tracks are named incrementally from the beginning of the alphabet (A,B,C...), with the northernmost tracks named first. Similarly, eastward tracks are named incrementally from the end of the alphabet (Z,Y,X...), with the southernmost tracks named first. Daily updates for each direction allow for routing around weather systems and tracking of favourable tailwinds to improve efficiency.

The map below shows the current valid NATs and the upcoming published NATs, along with the permissible flight levels in each direction.
Track Valid From Valid To Route East Levels West Levels
A 12 May 1130 UTC 12 May 1900 UTC RESNO 56/20 57/30 57/40 56/50 JANJO 350 370 390
X 12 May 0100 UTC 12 May 0800 UTC RAFIN 45/50 46/40 48/30 49/20 SOMAX ATSUR 320 340 360 380 400
Y 12 May 0100 UTC 12 May 0800 UTC SLATN 41/60 44/50 45/40 47/30 48/20 BEDRA NASBA 320 340 360 380 400
Y 13 May 0100 UTC 13 May 0800 UTC RAFIN 45/50 47/40 49/30 50/20 SOMAX ATSUR 320 340 360 380 400
Z 12 May 0100 UTC 12 May 0800 UTC 35/60 39/50 44/40 46/30 47/20 48/15 OMOKO GUNSO 320 340 360 380 400
Z 13 May 0100 UTC 13 May 0800 UTC SOORY 44/50 46/40 48/30 49/20 BEDRA NASBA 320 340 360 380 400
Warning: Do not use this data for real-world aviation or navigation. No guarantee of current accuracy is given.