I had an AIRPROX with a Black Kite during last week. We were about 12 ft apart, and his wingspan is 5 ft. As they are supposed to, he/she dived, although that may have been an optical illusion resulting from my sharp pull up and right turn. Looked as big as I have ever seen a bird, and it is probably as well that his/her back wasn't turned towards me. No warning from the radar service I was getting either.