Proposals to allow twin-engined civilian passenger jets to fly over the Arctic will dramatically reduce flight times and make destinations on the other side of the globe a one-flight hop.
Until now, regulators have insisted the planes must always be within three hours of a suitable place to land.
This is because mechanical problems on a twin-engine plane a potentially far more serious than for a jet with three or four.
But US airline authorities have now nearly doubled the time limit to five-and-a-half hours to take into account the vast improvements in aircraft engine technology.
It is expected that the European Aviation Safety Agency will follow suit.