What I saw was a large black bird with very conspicuous blocks of white on the TRAILING EDGE of the wings.
I glimpsed some bit of red on the head.
The total aspect of this bird was equally compelling. It flew with a generous grace, not the labored work that I associate with the Pileated. This may be a factor caused by the long slender wings, long pointed tail and less undulating flight. It took only a few wing beats to clear the area I was in.
The sun was still relatively low to the east. While looking at the bird, I needed to be sure that I was not looking at any sun reflections glinting off feather shafts. Because of the well defined shape of the trailing white blocks on this bird, I was fully confident that was not the case.
Also, I was sure that I was not looking at an abberant Pileated Woodpecker. Again, the well defined white features and the general shape and mannerisms of this bird ruled out that as a possibility in my mind.