G-Force One is a cool 727 that is operated providing zero g experience to people who are willing to pay.  It shows up at Seattle periodically, presumably because one of the tech companies is giving rides to some employees (but maybe it is just a rich person chartering it themselves).  Zero G is the company although the plane is operated on their behalf by Kalitta Charters.  I have had mixed luck shooting this plane but I did okay on this visit.  I got it arriving and heading out on a flight.  I missed the return and was actually driving along I-5 south alongside Boeing Field as it departed back to Long Beach.  Not the perfect combination but at least I got a few good shots of it this time.