Originally Posted by
jonnyjetprop
The biggest issue with flying the North Atlantic is that your options for changing altitudes and tracks are limited by the lack of positive radar control. It doesn't matter if your going east or west. Time of day is a factor because the available altitudes and tracks vary with time of day. There are more westbound in the morning and eastbound at night.
Doesn't the captain retain captains authority to deviate when required? I recall seeing reports of how on occasion, captains will exercise their authority to move off the track to go around bad weather on the NATs. I think some amount of paperwork is required afterwards to justify the action.