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	19 Sep 1130 UTC	19 Sep 1900 UTC	SOMAX 49/20 48/30 45/40 43/50 JEBBY CARAC		350 370 390
A	20 Sep 1130 UTC	20 Sep 1900 UTC	BEDRA 48/20 45/30 42/40 40/50 40/60 DOVEY		350 370 390
Y	20 Sep 0100 UTC	20 Sep 0800 UTC	RIKAL 53/50 56/40 57/30 57/20 PIKIL SOVED	320 340 360 380 400
Z	20 Sep 0100 UTC	20 Sep 0800 UTC	TUDEP 52/50 55/40 56/30 56/20 RESNO NETKI	320 340 360 380 400
Z	21 Sep 0100 UTC	21 Sep 0800 UTC	ELSIR 50/50 53/40 56/30 56/20 RESNO NETKI	320 340 360 380 400

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