Back in 1977, I was on an American Airlines flight from Los Angeles to Washington Dulles. It was a DC10 and we had a huge tailwind. Our flight was 2 hours and 40 minutes. Our ground speed was over 850 mph as we had to slow down for approach and landing. On the negative side, I was on the return flight and the same winds were there, so our trip back was over 6 hours.
Took a flight from Bozeman, MT to Atlanta one time in July of 2008. Arthur Blank was the first passenger off from the previous Atlanta to Bozeman flight that just came in. Got to meet him. Our flight home was less than 3 hours due to the tailwind. It was amazing.