Guidance concerning Air Navigation in and above the NAT MNPSA
On and to the north of the Night Datum Line FL360 and FL380 are delegated to Gander for use by Eastbound traffic.
To the south of the Night Datum Line FL360 will not be used for Gander eastbound traffic.
To the south of the Night Datum Line or the eastbound OTS, whichever is further South, FL380 will not be used for Gander eastbound traffic.
During the westbound OTS, FL330 is delegated by Gander to Shanwick for use by westbound traffic.
Between 0300Z and 0700Z, a static Datum Line, known as the North Datum Line, is established with the following coordinates:
LOMTA MOATT 60N50W 62N40W 63N30W
On and to the north of the North Datum Line FL380 is delegated to Reykjavik for use by Westbound traffic.
In the event of a high volume of North Random Flights and/or OTS Tracks the North Datum Line may be suspended to accommodate the dominate Eastbound flow.
NAT Doc 007