It was landing, it was low and slow, and I got a great look at it. I’m certain it was the Lockheed Martin F-35 Lightning II.
Image: http://upload.wikimedia.org/wikipedia/commons/f/fb/CF-1_flight_test.jpg
Very cool to see.
My office building in downtown Sunnyvale, CA is along the glide path for planes landing at Moffett Field. My window faces Moffett, and I’ve seen some interesting planes fly overhead as they land. I first heard it as it passed overhead, not in view, and then I saw it out the window, not far away.
Apparently it’s still in test and won’t be operational until late 2015.