Just saw this one pass over the Sim Building here at BFI on the way into SEA. I dont have a radio avail to hear Seatac… It didn’t look like a pax 747. In fact is was totally white, no ident markers anywhere on the body that I could see. And it was a cargo. No pax window at all. 3 Portholes on small upperdeck.
Also the only 747 in the flight path Ive seen since I got here at noon.