Drudge just posted this: http://philadelphia.cbslocal.com/2017/08/29/officials-mysterious-jets-over-philly-were-actually-saudi-arabian-aircraft/
Article claims, training at Nellis AFB.
I assume they are getting trained up on the new toys from the saudi/trump arms deal.
And I BET there will be more than just fuel on that tanker on the return trip.