My father was an Air Force Navigator in WW II. He was stationed in England. On D-Day he and a young pilot were scheduled for a training flight in some small, unarmed plane. D-Day of course was top secret and not known as D-Day at the time.
Anyway he was up flying around and suddenly there were hundreds of planes flying to France. With the amount of air traffic, they had to follow along, you just couldn't safely turn. So he flew across the English Channel in D-Day until things had thinned out enough that they could turn around and come back. .