Originally Posted by
2016parks
I read yesterday an item written by a reputable person who is also a private pilot, seemingly indicating that he experienced a 168 mph tail wind on January 1, providing a ground speed of 657 mph, I believe heading east across the US toward Washington, D.C. Is that possible? I can't provide a link, but it's in a tweet dated January 1 of @JamesFallows.
Perhaps not perfect but I have a speedometer on my phone which operates via GPS. On a flight from Manchester to Tel Aviv in January 2017 on an easyJet A320, I recorded a maximum speed of 646mph. And we only landed about 30 minutes ahead of time. So 657mph seems perfectly reasonable.