I was on a Delta 777 (I think it was) coming out of Narita heading for Portland, and we got in one MONSTER of a jet stream, and the “entertainment system moving map” thing said we were over 760 MPH. Had never had that happen before, or since.
,,, many years ago I was on a SWISS A340-600 out of LAX to ZRH. The flight left around 7pm - difficult to calculate when the New Year actually clocked in. After dinner and Champagne the crew were about to serve coffee and cancelled that. There was severe turbulence. The plane was being pushed, for certain. It was the middle of the night and somewhere between Hudson Bay and Greenland I was wondering how long the rivets would hold out. I’m here to tell the story though. That was one of the roughest flights I’ve had. The worst of it ran for about two and a quarter hours.