On the common at Shipbourne,the local artist,pointed out this bird as it took flight.The undersides of it's wings were large white patches.Not covering the whole of the undersides of each wing.Use your zoom and get a reasonable shot,says he.LOL.This was at 400mm.
He said it was a Buzzard.Strangely,50 years ago,I would have known.Sadly,no more.
see http://www.rspb.org.uk/wildlife/birdguide/name/b/buzzard/index.aspx