I’m not sure but it sure doesn’t seem like any of the world, outside of the usa, seems to understand the concept or the dangers of Jetstreems. I’m honestly really concerned about flying international and am really disappointed that they don’t seem to be considered. Mt winds are not really the issue as much as complete avoidance of the polar/ hadley currents.
Hitting a Jetstream perpendicular can drop a plane right out of the air. Similar to being hit by a train. There are going to be some serious, serious accidents if companies, pilots & fispatchers, don’t become more diligent. Where is the icao in this?