On the B4U FLY app it shows you the airports in your current location that are within 5 miles of you. It states the law says you are supposed to notify any of the airfields within the 5 miles before you fly. I have little small privately owned backyard airfield's come up on the map and even some smaller airports. How are you supposed to look up all of these airports and private airfields that come up on the map and find a phone number for all of them? It would take you a week to do so! I don't understand it, there is no contact info on the app? Maybe I'm missing something here!