Yes, and birds don't fly all that fast, unless they are acting like dive bombers, in which case their wings are not propellering. And your point was? Personally, I am not interested in the aerodynamics of birds. If you are, I suggest you find another site. As far as responding to my "critical comments", I would appreciate it if you would stick to the subject and provide a rational, fact filled rebuttal. As far as quality is concerned, I have not seen one useful piece of information arise from your comments.