If you are seeing a B-24 "liberator" it belongs to the collings foundation.
http://www.collingsfoundation.org/ They own the only flying example in the world. They also have a B-17 and are touring in southern California right now.
Somehow my parents managed to buy a house that is right in the take off pattern of there "home base" in Stow Massachusetts. During the summer we pretty consistently have the single engine prop planes flying over and once a summer or so the B-17 and 24 will make a few passes. It is definitely very cool to see those things flying right above your head.