My flight from Oslo to LHR was delayed by a couple of hours due to the need to change the inbound aircraft at that came from LHR. We departed OSL at 23.15 local and the pilot made every effort to make up as much time as possible. During the flight when I glanced up at the in flight map I was quite surprised to see a ground speed of 1000Km/h (622 Mph) for a short while. We did have a significant 150Km/h tail wind, but I don't think I've ever seen a 1000Km/h ground speed before.
I'm curious as to what's the fastest ground speed anyone else has seen?

I lost track of time a little on the flight but I think we did OSL-LHR wheels up to wheels down in about 85 mins. The cabin crew were certainly taken by surprise when the pilot announced 10 mins to landing with a mad scramble to clear everything away. Then when landing at LHR (23.45), no rush to slow down on the runway and we drove all the way down the runway to turn off right at T5. Only one immigration desk open and the e-gates closed. Certainly the quickest I've done OSL-LHR.