Hi Jeff, the link doesn't work on the computer im using (rarely does) but, for a moment there, I thought you might have come across one of those rarely awarded Low flying aircraft destruction strips. ;-))
It showed a line of various machine guns firing on a model plane as it flew back and forth in front of the guns. They had to shoot for a while to hit it.
I know its not a WW2 answer, but In the Falkland - UK Conflict, we would be lying on our belly because we had aircraft noise, we would wait for the Mirages to appear, by the time you heard them and lifted your rifle up to engage them, they were past and long gone, to shoot an aircraft down virtually impossible or you have to be very very lucky.