Significant crop in high key sky. Barely salvageable image.
But even though this guy was quite far away, I used a different technique that I haven't been using on my camera and all images in flight were in pretty good focus. (Focus Area and on Continuous Mode)

I remembered afterwards that this was the technique I used early last year with great success on birds in flight.
Now why didn't I remember that afterwards?

PS. I was waiting for an eagle in a tree to fly so I could photography in flight. Saw this bird flying by in the corner of my eye, switched to this focusing mode and realized it was another eagle, to my surprise.

And this wasn't the same one I photographed on the River Road. Wow, 3 eagles captured in one day!