In short, we don't.
What we can do is make educated guesses.
The jet is very much the private jet of Mr Lerner.
It is based at East Hampton, NY, which is the far reaches of Long Island, and probably one of the more 'remote' areas of NY (if that's possible)
In order to fly transatlantic eastbound it needs to first go to West Hampton for enough runway with a full fuel uplift.
It is therefore fair to assume that if the flight originates in East Hampton without a pick up in a metropolitan area, then the man is on it.
For the record it landed at Luton 1014 on Friday and departed 0959 on Saturday. The time suggested in my Saturday evening arrival back in the USA posting was wrong. One of my resources sometimes recalculates times and sometimes doesn't!
I will continue to monitor things and advise if it points this way again. I will not advise times or arrival points until after any flight has been completed, which you may have noticed is the way that I have done things up until now.
Here's to another interesting week!
Fascinating stuff thetrees.
Think I'm going to knock this messageboard on the head.It just doesn't do it for me anymore.
Boeingtalk.com for me from now on