What ground speeds are found on flights over Japan. I remember in WWII the US Army Air Corps needed to switch from precision bombing to area fire bombing because wind speeds at B-29 bombing altitude sometimes exceeded 200 mph and the bombsights could not compensate for the variations of wind speed over the altitudes through which they fell. I remember my first trip from North America to Tokyo by the ground speed we making down the Kamchatka peninsula we were going to arrive a couple hours early. Then the ground speed started dropping, and dropping, and dropping, and I began to wonder if we were ever going to get there although Kamchatka is very scenic. I remembered war history and the wind problem - we arrived right on schedule. So flying from Tokyo to North America I thought 800 mph ground speeds would be quite common. After all flying toward Tokyo I remember reaching ground speeds lower than 350 mph on just a normal trip.