ETOPS flights are regularly flown 3+ hours from a suitable place to land (single-engine flying time). Considering they are up to 370 minutes (about 6 hours) in

ETOPS flights are regularly flown 3+ hours from a suitable place to land (single-engine flying time). Considering they are up to 370 minutes (about 6 hours) in some extreme cases, I can certainly see this being a problem. If you had a 3h warning at any given moment, there's a strong possibility that some jetliner somewhere in the world is over an ocean and could not land in time.