[bertil]

Didn’t get down-voted overall so fine on that end.

I actually never though of the existence of a continuous cone of focus outside of the plane — the graph I had seen were all focused on the whether the plane heard it.

I guess an alternative option would be to find routes above the polar circle, or through the narrow of Central america — but the increased distance would make it less interesting at “just” Mach 2.2.