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 table 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	04 Apr 1130 UTC	04 Apr 1900 UTC	DINIM 51/20 51/30 50/40 48/50 NICSO		350 360 370 380 390
A	05 Apr 1130 UTC	05 Apr 1900 UTC	DOGAL 55/20 55/30 54/40 52/50 TUDEP		340 350 360 370 380 390
Y	05 Apr 0100 UTC	05 Apr 0800 UTC	ALLRY 51/50 51/40 51/30 51/20 DINIM ELSOX	330 340 350 360 370 380 390 400
Z	04 Apr 0100 UTC	04 Apr 0800 UTC	LOMSI 55/50 56/40 57/30 57/20 SUNOT KESIX	320 330 340 350 360 370 380 390 400
Z	05 Apr 0100 UTC	05 Apr 0800 UTC	JOOPY 49/50 49/40 48/30 48/20 48/15 ETIKI REGHI	330 350 360 380 390 400

Pacific Organised Track System (PACOTS) tracks are daily high altitude pacific routes between eastern Asia and the western coast of North-America. Eastward tracks are named numerically (1,2,3...). Similarly, westward tracks are named incrementally from the beginning of the alphabet (A,B,C...). Daily updates for each direction allow for routing around weather systems and tracking of favourable tailwinds to improve efficiency. The table below shows the current valid PACOTS tracks and the upcoming published PACOTS tracks.

Track	Valid From	Valid To	Route