Every day 4,000 flights cross the North Atlantic, where there is very limited radar coverage. How is the flow controlled? KLM explains the process in one of their interesting “Cockpit Tales” videos. An aircraft flies on a track determined by ATC, which sets a precise entry point and time for each flight. Once in, the aircraft observes tight speed and altitude parameters, which are communicated by satellite back to ATC. The pilots monitor their progress very carefully. Note the paper checklists!
Another example of the complex behind-the-scenes planning which makes modern commercial flight safe and reliable!